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WRc Ref: UC8720.05
February 2012
Analysis of Poly-Brominated Biphenyl Ethers
(PBDEs) in Selected UK Waste Streams:
PBDEs in waste electrical and electronic equipment
(WEEE) and end of life vehicles (ELV)
RESTRICTION: This report has the following limited distribution:
External: Defra
© WRc plc 2012 The contents of this document are subject to copyright and all rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted, in any form or by any means electronic, mechanical, photocopying, recording or otherwise, without the prior written consent of WRc plc.
This document has been produced by WRc plc.
Any enquiries relating to this report should be referred to the Project Manager at the following address:
WRc plc,
Frankland Road, Blagrove,
Swindon, Wiltshire, SN5 8YF
Telephone: + 44 (0) 1793 865000
Fax: + 44 (0) 1793 865001
Website: www.wrcplc.co.uk
Analysis of Poly-Brominated Biphenyl Ethers
(PBDEs) in Selected UK Waste Streams:
PBDEs in waste electrical and electronic equipment (WEEE)
and end of life vehicles (ELV)
Report No.: UC8720.05
Date: February 2012
Authors: James Peacock, Jane Turrell, Kathy Lewin and Edward Glennie
Project Manager: Jane Turrell
Project No.: 15613-0
Client: Defra
Contents
Glossary ................................................................................................................................... 1
Executive Summary ................................................................................................................. 2
1. Introduction .................................................................................................................. 8
1.1 Overview ..................................................................................................................... 8
1.2 Objectives .................................................................................................................... 9
1.3 Background ................................................................................................................. 9
1.4 Total UK WEEE and links to brominated plastics ..................................................... 10
2. Sampling and Testing ............................................................................................... 12
2.1 Sampling ................................................................................................................... 12
2.2 Testing ....................................................................................................................... 15
3. Results ...................................................................................................................... 18
3.1 Introduction ................................................................................................................ 18
3.2 XRFS screening ........................................................................................................ 18
3.3 GCMS analysis .......................................................................................................... 21
4. Discussion ................................................................................................................. 26
4.1 PBDEs in UK WEEE ................................................................................................. 26
4.2 Estimates of PBDEs in UK Waste stream ................................................................. 31
5. Conclusions and Proposals ....................................................................................... 35
5.1 Overview of PBDE congeners in UK WEEE ............................................................. 35
5.2 Levels of listed PBDEs in waste electrical and electronic equipment ....................... 36
5.3 Levels of PBDEs in ELV ............................................................................................ 36
5.4 PBDE Quantification by High Resolution GCMS ...................................................... 36
5.5 Suitability of XRFS as a screening tool ..................................................................... 37
5.6 Proposals for further work ......................................................................................... 37
References ............................................................................................................................. 39
Appendices
Appendix A PBDE Method Development ................................................................... 40
Appendix B Results ..................................................................................................... 43
List of Tables
Table 1.1 UK Waste electrical & electronic equipment (WEEE) collected in 2010
1 .................................................................................... 10
Table 1.2 UK Waste electrical & electronic equipment (WEEE) collected 2010
1 ........................................................................................ 11
Table 2.1 Details of samples collected for PBDE testing ........................................ 13
Table 3.1 PBDE congeners analysed in GCMS analysis ........................................ 19
Table 4.1 Unweighted range data (GCMS) for PBDEs Waste electrical and electronic equipment (WEEE) .......................................................... 26
Table 4.2 Weighted range data (GCMS) for PBDEs Waste electrical and electronic equipment (WEEE) .......................................................... 28
Table 4.3 Weighted average concentrations of the sum of Stockholm listed PBDEs and total PBDEs by WEEE stream ................................... 29
Table 4.4 Summary PBDE data for WEEE ............................................................. 30
Table 4.5 Estimated weights of Stockholm listed PBDEs in key UK WEEE streams ........................................................................................ 34
Table B.1 Samples submitted for GCMS analysis and XRFS screening data .......................................................................................................... 43
Table B.2 MSS GCMS PBDE test data ................................................................... 44
Table B.3 Detailed breakdown of MSS GCMS analysis data .................................. 46
Table B.4 Correlation in GCMS data between hepta- and deca-BDE ..................... 48
Table B.5 Estimated confidence limits for range estimates of PBDEs in UK waste stream ..................................................................................... 50
Table B.6 Samples tested for interlaboratory comparison ....................................... 51
Table B.7 Summary of MSS and Fraunhofer PBDE results .................................... 52
Table B.8 Comparison of MSS and Fraunhofer PBDE results ................................ 53
Table B.9 Summary of interlaboratory GCMS data comparison ............................. 54
List of Figures
Figure 2.1 Sampling approach for PBDEs in WEEE and ELV ................................. 14
Figure 3.1 Concentration of bromine in selected electrical components by portable XRFS unit ............................................................................. 20
Figure 3.2 Plot showing range of concentrations of Br in samples of computer casings by XRFS ..................................................................... 21
Figure 3.3 PBDE concentrations in various whole electrical components taken from UK waste sites ....................................................................... 22
Figure 3.4 Plot showing PBDE concentrations in a bulk sample of shredded computer casings .................................................................... 24
Figure 3.5 Plot showing PBDE concentrations in bulk sample (A17) of shredded computer casings excluding nona- and deca-BDE ................. 25
Figure 3.6 Plot showing PBDE concentrations in sample (A28) - television casings .................................................................................... 25
Figure 4.1 Plot showing PBDE concentrations in shredded bulk WEEE samples ................................................................................................... 27
Figure B.1 Histogram of hepta-BDE concentrations in all WEEE categories, excluding TVs ....................................................................... 47
Figure B.2 Histogram of hepta-BDE concentrations in sampled TVs ....................... 47
Figure B.3 Scatter graph hepta and deca PBDE concentrations (all ‘whole’ samples & sub-samples) ............................................................. 48
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Glossary
Aqua regia Mixture of hydrochloric and nitric acid, used hot to digest solid samples for determination of mineral acid soluble ‘total’ concentration
ASR Automotive shredder residue
BS EN 14899 British/European Standard Framework for the Development of a Sampling Plan
CEN/TC292 European Committee for Standardization Technical Committee 292 – on the characterisation of waste
ELV End of life vehicles
EU European Union
GCMS Gas chromatography – mass spectrometry – an analysis technique used for determination of PBDEs
HIP High impact polystyrene
ICER Industry Council for Electronic Equipment
LOD Limit of detection
MSS Marchwood Scientific Services
PBDEs Polybrominated diphenyl ethers – a group of compounds used as a flame retardant in plastics used in electronics
Printed circuit board Printed circuit board
PeCB Pentachlorobenzene
POPs Persistent organic pollutants
PUR or PU Polyurethane
RoHS Restriction of hazardous substances
TBBPA Tetrabromobisphenol A
UNEP United Nations Environment Programme
WEEE Waste electrical and electronic equipment
XRFS X-ray fluorescence spectrometry
(xxx)-BDE Brominated diphenylether – where (xxx) denotes the level of bromination (hepta-, octa-, nona- deca- etc.)
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Executive Summary
i Background
Polybrominated diphenyl ethers (PBDEs) have been in use as flame retardants in plastic and foam
items within electrical and electronic equipment and motor vehicles since the 1970s, and as such will
be present in the waste stream of these products when they are discarded. There are a total of 209
PBDE congeners, which are categorised into 10 groups on the basis of their level of bromination, using
a pre-fix i.e. tri-, tetra-, penta-, hexa-, hepta-, octa, nono- and deca-BDE.
As part of implementation of the Persistent Organic Pollutants Regulation (Regulation 850/2004/EC)
the EU intend to set limit values for new substances added to the annexes of the Stockholm
Convention on Persistent Organic Pollutants (2009) for specific waste streams which include waste
electrical and electronic equipment and end of life vehicles. The impact of such limit setting on UK
business is unclear as the data on PBDEs levels in these waste streams is sparse.
Newly listed substances under the Stockholm Convention include the fire retardants tetra- penta-, hexa-
and hepta-BDEs. Although their use in manufacture has been restricted within the EU since 2003-4,
they may still be present in items within waste electrical and electronic equipment and end of life
vehicles that are manufactured outside of the EU or that incorporate plastic recyclate that contains
listed PBDEs.
This report details the information collected through a Defra funded project to generate new data on the
ranges of PBDEs found in United Kingdom (UK) waste electrical and electronic equipment and end of
life vehicles to support Defra in the implementation of the Persistent Organic Pollutant Regulation. This
study provides initial quantification of the concentration ranges of PBDEs that might be expected in the
plastics and foam components of waste electrical and electronic equipment. Further testing is required
to confirm the extent of the concentration ranges found in waste electrical and electronic equipment
component stream. Samples of end of life vehicles will be collected in January 2012.
ii Approach
A laboratory based high resolution gas chromatography with mass spectrometry method was
developed by a UK laboratory to enable testing of PBDEs in plastic matrices. Target congeners, which
are the primary constituents of commercial flame retardant formulations were used as markers for each
of the bromination groups. WRc collected samples of waste electrical and electronic items from a
number of UK sites and processes where Waste Electrical and Electronic Equipment is treated to
assess the degree of contamination in the overall waste stream and attempt estimates for PBDE
concentrations in UK waste electrical and electronic equipment. The use of a portable X-Ray
fluorescence spectrometer to provide a crude screen for the presence of total bromine, as a potential
indicator of PBDE contaminated plastics was also investigated. A protocol was developed based on a
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30 second scan time. This provides a limit of detection for total bromine of circa 5-10 mg/kg, and
equates to a detection limit in a brominated compound containing 50% bromine (i.e. penta PBDE) of
approximately 10 to 20 mg/kg. The detection limit would be slightly better for a compound with a higher
level of bromination.
The aim of the sampling programme was to collect samples for testing by sensitive analytical
techniques and assess the usefulness of X-Ray fluorescence spectrometry as a screening tool for
PBDEs that could be used in the field.
The sampling programme aimed to encompass a good cross-section of waste electrical and electronic
equipment fractions to provide an indication of common contaminant concentration ranges. The
samples collected represent circa 97.5% of total UK waste electrical and electronic equipment waste
arisings. Sample collection and testing focussed on shredded ‘single component’ waste electrical and
electronic equipment rather than whole single items. This approach ensured that the majority of
samples, although spot samples in time, were representative of a large number of individual units and
therefore the wider UK waste stream.
iii Conclusions
Overview of PBDE congeners in UK waste electrical and electronic equipment:
Consistently low (in terms of fire retardant concentrations) but detectable levels of the newly listed
PBDEs of interest were seen in all items tested. Since it is believed that these samples are
representative of wider UK waste electrical and electronic equipment, this equates to widespread listed
PBDE contamination across this stream. The presence of listed PBDEs is usually, but not always,
associated with higher and more variable concentrations of nona-and deca-BDEs. Nona-206 and deca-
209 BDEs are the dominant PBDEs found in both single component waste electrical and electronic
equipment and shredded waste electrical and electronic equipment consisting of multiple components.
Both nona and deca PBDEs are still routinely used as flame retardants in manufacturing, but neither
are Stockholm Convention listed persistent organic pollutants.
Levels of listed PBDEs in waste electrical and electronic equipment: Typical weighted
average concentrations of the sum of listed PBDEs (i.e. tetra-, penta-, hexa-,and hepta- BDE) versus
total PBDE concentrations (i.e. including nona- and deca- BDE) are provided in Table 1. The table is
colour coded, showing highest concentrations in red, through orange to green which represent the
lowest concentrations. The significant concentrations of listed PBDEs in printed circuit boards, TVs and
industrial IT equipment are such that they may exceed future EU limits. This is of major significance if
we consider that the contribution of IT equipment and TVs is circa 34% of the total UK waste electrical
and electronic equipment stream and potentially poses a significant problem to waste electrical and
electronic equipment recycling in the UK. Management measures may be needed to remove
contaminated material prior to re-processing. The PBDE concentrations detected in all the waste
electrical and electronic equipment streams tested in this study would fail to meet some proposed lower
limits for some PBDE bromination groups. Of the listed PBDEs, hepta-BDE and to a lesser extent hexa-
BDE appear to be the predominant listed contaminants, particularly in TVs, IT equipment (PC monitors)
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and digiboxes. Each sample of shredded waste electrical and electronic equipment tested by GCMS is
representative of at least 100 units, although the number of samples tested in relatively small, 42 in
total (and smaller within each waste stream) the data is believed to provide a representative snap-shot
of each waste stream.
The concentrations of listed PBDEs vary from < 1 - 36,500 mg/kg but are generally below 5000 mg/kg.
This concentration is too low to be effective as a flame retardant and it is believed that these plastic
items have been contaminated through incorporation of plastic recyclate containing listed PBDEs into
new manufactured products.
Table 1 Average concentrations of Stockholm listed PBDEs versus total PBDEs in UK
waste electrical and electronic equipment as determined in this study
Category Average total tetra, penta,
hexa, hepta- PBDE (mg/kg)
Average total PBDE
(mg/kg)
TVs 5746 90777
Industrial IT equipment 4610 29073
Printed circuit boards 4473 26493
Digiboxes 858 5825
Large household appliances 512 1951
Small household appliances 57 847
Fridges 39 182
PC monitors 14 12353
Sum of Stockholm listed PBDEs Sum of total PBDEs
This suggests that although dilution of listed PBDEs will occur during repeated recycling, it will take a
considerable time to eradicate these substances from the waste electrical and electronic equipment
stream unless measures are put in place to remove them prior to re-processing or the process has a
suitable separation stage. From the initial findings of this study it could be a number of decades before
the UK might expect to see PBDE free consumer goods being discarded.
Estimates have been made of the proportion of waste contaminated by Stockholm Convention listed
PBDEs for the UK waste stream in Table 2, but these should be viewed with caution for a number of
reasons:
Firstly, data on waste arisings are only available at an amalgamated level for generic categories
e.g. the category ‘display equipment’ contains both TV and PC monitors that have been found to
have differing PBDE characteristics. The proportion of the total weight of the PBDE containing
components requires further verification and in some cases this data is not currently available.
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Table 2 Estimated weights of Stockholm listed PBDEs in key UK WEEE streams
Waste
Category
UK Arisings Data
2010
Brominated
plastics in
waste
(Empa)1
No.
Samples
Mean
PBDE UK
samples
Weight Stockholm listed
PBDEs UK WEEE (tonnes)
tonnes % % mg/kg Best
estimate
Lower
limit
(5%ile
Upper
limit
(95%ile)
Large household
appliances 141,236 31.0 0.29 6 762.2 0.312 0.067 0.817
Small household
appliances 22,870 5.0 0.75 1 57.4 0.003 0.001 0.009
Fridges 97,414 21.0 10.0 1 39.3 0.010 0.003 0.022
ICT & consumer
electronics 186,435 40.0 18.0 9 3140.2 123 53 242
Other waste (not
sampled) 13,265 3.0
Total 461,220 100.0
Note:
Single pieces from 6 items. Bulk sample from multiple shredded units. Empa do not provide a figure for the level of brominated plastics in cooling appliances, WRc have assumed that it is higher than other large household appliances due to the plastic internal construction of a fridge or freezer but less than ICT where the outer frame consists of brominated plastic.
Secondly, the sampling approach was developed on the working assumption that X-Ray
fluorescence spectrometry screening would show that the majority of plastic pieces (each
representing a unit) would not contain PBDEs and that certain waste streams could be excluded
from the gas chromatography mass spectrometry (GCMS) analysis. This would have meant that a
larger number of samples could be tested within selected component waste streams to increase
certainty in the range data produced. In the event the screening showed that the majority of the
data shows that that there was detectable contamination across all target waste electrical and
electronic equipment and it was therefore necessary to spread the available GCMS testing
resource across all component streams. The range of data for each congener group is wide and
the number of samples in each category smaller than was originally intended and this hinders any
attempt to estimate the quantities of PBDEs in the overall UK waste stream with acceptable
certainty. Specifically the estimates of listed PBDE in UK waste electrical and electronic equipment
would be substantially improved if the number of samples in each category is increased by further
1 Empa (Swiss Federal Laboratories for Materials Science and Technology ). Empa: http://ewasteguide.info/introduction/e-waste
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sampling and testing to allow the corresponding distributions of PBDE concentrations to be
estimated: i.e. confirmation of lognormality, and summary statistics including the mean, variance
and upper and lower percentiles.
Levels of PBDEs in End of Life Vehicles: Samples will be collected in January 2012 to address
the gap in new data for end of life vehicles. Data will be reported to Defra as a supplementary Annex to
this report.
PBDE Quantification by High Resolution Gas Chromatography Mass Spectrometry: A
PBDE test method was developed to support this programme of work. Despite extensive method
development the determination of PBDEs in plastic and foam matrices continues to be a challenge
although a UK laboratory is now in a position to test for target PBDEs in the plastic from waste electrical
and electronic equipment. However, the technique requires a specialist laboratory, a multi-stage
sample preparation and extraction procedure and high resolution gas chromatography mass
spectrometry to test the final sample. The method is capable of determining sub 0.05 mg/kg of
individual PBDE congeners in waste electrical and electronic equipment plastics, but the complexity,
and cost of the test, means it is not a tool that is applicable to routine process monitoring. This may also
have implications for regulatory monitoring of PBDEs. The analytical methodology used to undertake
analysis of plastic samples by Marchwood Scientific Services has been optimised for the determination
of PBDEs in plastic materials. The use of labelled internal standards allows concentration of PBDEs to
be determined using internal standardisation which allows recovery correction of PBDE data. This
approach eliminates the need for correction equations (or recovery factors), and is an established and
widely applied in a wide range of analytical applications. The method requires the assessment of PBDE
recovery from a matrix sample to provide full method validation (a ‘blank’ or low PBDE plastic reference
sample could not be obtained within the timeframe of the method development activities but this will be
addressed if further testing is required). Criteria for acceptance of calibration samples (including a
standard reference material) and internals standard recovery have been agreed for future testing. A
small interlaboratory comparison exercise indicates acceptable data comparability between the new
method and test data generated by a European test facility which has considerable experience of
testing WEEE matrices.
Suitability of X-Ray fluorescence spectrometry as a screening tool: X-Ray fluorescence
spectrometry provides a rapid technique for the assessment of total bromine in end of life vehicles and
waste electrical and electronic equipment. Any limitations in the technique arise from the fact that it
cannot distinguish between PBDEs and other bromine containing compounds or determine which
PBDEs are present in the sample i.e. whether the PBDEs listed in the annexes of the Stockholm
Convention on Persistent Organic Pollutants are present. This aside with the exception of printed circuit
boards which are known to contain tetrabromobisphenol A, the correlation between X-Ray fluorescence
spectrometry data and GCMS indicates that PBDEs appear to be the primary bromine containing
compound in other waste electrical and electronic equipment. Many of the samples tested provide low
<100 mg/kg total bromine but this could be consistently linked to low concentrations of listed PBDEs,
Such low concentrations of PBDE have little value as flame retardants and it is concluded that this is
consistent with recycling of listed PBDEs in the waste plastic stream into new products. Conversely
where bromine concentrations exceeded 1% w/w whilst the majority of this could be attributed to non-
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listed PBDEs that are legitimately being added during manufacture low levels of listed PBDEs are also
present. We conclude that X-Ray fluorescence spectrometry can be used as a crude but effective
screening tool to identify waste electrical and electronic equipment and end of life vehicle residues
containing bromine and potentially PBDEs. The results of this relatively limited study suggest that a
positive X-Ray fluorescence spectrometry bromine result provides a good indicator measure for the
presence of listed persistent organic pollutants. In particular very low total bromine concentrations
(<500 mg/kg) are often linked specifically to listed PBDEs.
iv Proposals for further work
The authors suggest that the precision associated with PBDE concentrations in the current dataset
could be improved with further analysis of the available sample bank collected for this study. This
should focus on the apparently high levels of hepta-BDE in all waste electrical and electronic
equipment streams.
Further sampling and testing should be targeted at:
establishing with further certainty the profile of PBDE concentrations in each
component and sub-component category; and
waste streams which exhibit the widest concentration ranges and which represent high
volume waste streams to improve both the weighted average and reduce uncertainty in
any grossing up estimates.
A detailed breakdown of UK waste electrical and electronic equipment arisings is required at a
finer level than currently published Environment Agency data to allow derivation of grossed up
averages of PBDEs in the total waste stream. Further data is required on the percentage
contribution of the hard plastic components to the total weight of each unit to further improve the
accuracy of any grossing-up activity.
v Résumé of Contents
Section 1 and 2 provide background to the project and the approach taken to sample collection and
testing. Section 3 presents summary test data for both X-Ray fluorescence spectrometry screening and
laboratory testing of waste electrical and electronic equipment. The conclusions from this work and
findings regarding the PBDE content of the UK waste electrical and electronic equipment waste stream.
Appendix A provides a summary of the method development work undertaken to enable the testing of
PBDEs in plastics and Appendix B provides the X-Ray fluorescence spectrometry and gas
chromatography with mass spectrometry test data by PBDE congener.
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1. Introduction
1.1 Overview
Polybrominated diphenyl ethers (PBDEs) have been in use as flame retardants in plastic and
foam items within electrical and electronic equipment and motor vehicles since the 1970s, and
as such will be present in the waste stream of these products when they are discarded. There
are a total of 209 PBDE congeners, which are categorised into 10 groups on the basis of their
level of bromination, using a pre-fix i.e. tri-, tetra-, penta-, hexa-, hepta-, octa, nono- and deca-
BDE.
As part of implementation of the Persistent Organic Pollutants Regulation (Regulation
850/2004/EC) the EU intend to set limit values for new substances (newly listed) added to the
annexes of the Stockholm Convention on Persistent Organic Pollutants (2009) for specific
waste streams which include waste electrical and electronic equipment (WEEE) and end of
life vehicles (ELV). The impact of such limit setting on UK business is unclear as the data on
PBDEs levels in these waste streams is sparse.
Newly listed substances include the fire retardants tetra- penta-, hexa- and hepta-BDEs.
Although their use in EU product manufacture has been restricted within the EU since 2003-4,
they may still be present in items within WEEE and ELV that are manufactured outside of the
EU or that incorporate plastic recyclate that contains listed PBDEs.
This report details the information collected through a Defra funded project to generate new
data on the ranges of PBDEs found in United Kingdom (UK) WEEE and ELV to support Defra
in the implementation of the Persistent Organic Pollutant Regulation. Data on the PBDE
content of the plastics and foam components of waste electrical and electronic equipment and
end of life vehicle residues requires some further refinement, although this study provides an
initial measure of the concentration ranges of PBDEs that might be expected in these waste
streams.
Method development was required to ensure that quantification of the PBDE content was
sufficiently robust to enable informed decisions to be taken about limits that could be
implemented within the EU.
WRc collected samples of different WEEE arisings from a number of UK collection and
reprocessing sites to assess the degree of contamination of listed substances PBDEs in the
overall UK waste stream. Access to the ELV waste stream will be achieved in December 2011
and new data will be produced for this stream.
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1.2 Objectives
To derive statistically sound estimates for PBDEs present in a wide-range of UK WEEE
and ELV waste-streams, using sensitive laboratory GCMS (Gas Chromatography with
Mass Spectrometry) analysis.
To determine the suitability of XRFS (X-Ray Fluorescence Spectrometry) for the
screening of WEEE and ELV wastes for PBDEs. Such screening may have value in
providing a means to separate high PBDE waste streams prior to re-processing and
facilitate removal of contaminated material from the reprocessed stream.
1.3 Background
Polybrominated diphenyl ethers are additive brominated flame retardants i.e. they are not
blended into the matrix and as such may be available for leaching from products and wastes
and therefore move into the wider environment. There are a total of 209 PBDE congeners,
which are categorised into 10 groups on the basis of level of bromination, with a pre-fix
referring to the level of bromination i.e. tri-, tetra-, penta-, hexa-, hepta-, octo-, nono- and
deca-BDE.
The current Defra study is focused on determining the levels of Stockholm listed POPs tetra,
penta-, hexa- and hepta-BDEs in selected waste streams. However, it was important to
determine the concentrations of other congeners because:
commercial ‘C’ formulations of the flame retardants nominally comprising one congener
group level are often a mix of congeners. For example, the main constituents of C-
Penta are 28-35% tetra BDE-47 and 44-51% penta BDE-99 and 100 in addition to
much smaller concentrations of tetra BDE-49 and -66, penta BDE-85, hexa BDE-138, -
153 and -158. C-Octa contains predominately octa BDE-203 and hepta BDE-183, but
up to 14% hexa BDE-153, 10% nona BDE-206 and trace levels of hexa BDE 154,
penta BDE-99 and tetra BDE-47. C-Deca which is not a Stockholm listed formulation
consists of >98% deca BDE-209. The exact composition of commercial formulations
vary. A single unit e.g. a fridge can contain components from a range of suppliers which
contain varying levels of PBDEs.
data produced using the portable XRFS can be compared with laboratory GCMS data
to assess its value as a screening tool. XRFS provides a measure of ‘total’ bromine in a
sample i.e. inorganic and organic species.
C-Penta BDE products are commonly added to polyurethane foams used in mattresses,
upholstered furniture and carpet padding. C-Octa BDE products are added to acrylonitrile-
butadiene- styrene (ABS) used in computer and appliance casings. C-Deca BDE is the most
widely used PBDE in the global market and is added to polystyrene, polypropylene and other
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thermoelastic polymers used in adhesives, insulation as well as casings for televisions and
computers.
1.4 Total UK WEEE and links to brominated plastics
The Environment Agency report that approximately 460 000 tonnes of WEEE was collected in
the UK in 20102. This predominantly comprised:
large household appliances (washing machines, dishwashers and electric cookers) at
31% by weight of the total;
cooling appliances (fridges and fridge freezers) at 21% of total weight; and
display equipment (televisions and computer monitors).
Arisings data for UK WEEE is provided in Table 1.1.
Table 1.1 UK Waste electrical & electronic equipment (WEEE) collected in 20101
Category Name Total separately collected
household WEEE
Proportion
(%)
Large Household Appliances 14,1236 31
Small Household Appliances 22,870 5
IT and Telecoms Equipment 29,548 6
Consumer Equipment 27,150 6
Lighting Equipment 0.4 0.0001
*Electrical and Electronic Tools 10,661 2
*Toys, Leisure and Sports 1,286 0.28
*Medical Devices 10 0.0022
*Monitoring and Control Instruments 606 0.13
*Automatic Dispensers 0.0 0.00
Display Equipment 12,9737 28
Cooling Appliances Containing Refrigerants 97,414 21
*Gas Discharge Lamps 701 0.15
Total 46,1220 100
Note: * Not sampled as part of this sampling programme, but the total weight of these streams represents 2.6% of
the total waste stream).
2 Environment Agency (2011) Waste electrical and electronic equipment UK data reports
http://www.environment-agency.gov.uk/business/topics/waste/111016.aspx
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The plastics fraction in WEEE varies between 10 to 40% of the total unit weight.
Empa (Swiss Federal Laboratories for Materials Science and Technology )3 have produced
data on the percentage of brominated plastics (PBDE, TBBA and PBB) in WEEE. This data
has been used to produce grossed estimates of PBDEs in UK WEEE in conjunction with the
data in Table 1.1.
Some assumptions have been made to align the two sources of information (Table 1.2).
Table 1.2 UK Waste electrical & electronic equipment (WEEE) collected 20101
Category Name Sub-categories
%
brominated
plastics,
% UK WEEE
stream
Large Household Appliances
Cookers, dishwashers, tumble dryers
0.29 31%
Small Household Appliances
Microwaves, kettles, toasters, hoovers,
0.75 5%
ICT and consumer electricals
PC monitors, TV’s, industrial IT equipment
18.0 40%
Cooling equipment Fridges and freezers 10.0 21%
Note:
percentage of the weight of an individual unit.
brominated plastics include PBDE, TBBA and PBB.
Empa do not provide a figure for the level of brominated plastics in cooling appliances, WRc have
assumed that it is higher than other large household appliances due to the plastic internal construction
of a fridge or freezer but less than ICT where the outer frame consists of brominated plastic.
This data has been used in conjunction with the test data from this programme for each of
these component categories to estimate the quantities of PBDEs in UK WEEE in Section 4.2.
3 Empa: http://ewasteguide.info/introduction/e-waste
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2. Sampling and Testing
2.1 Sampling
2.1.1 Development of sampling plan
The aim of the sampling programme was to collect samples that encompassed as many
common waste fractions as was possible, to provide an indication of common contaminant
concentration ranges. This dictated that the sampling approach required collection of multiple
samples of similar waste streams ensuring that sampling encompassed the range of
applications of PBDEs in WEEE and ELV.
A sampling plan was developed that followed the elements outlined in BS EN 14899 the
European framework standard for the sampling of wastes developed by CEN TC 292 Waste
Characterisation. The sampling approach was documented to allow future sampling activities
to be consistent with the current programme.
It was assumed that the production of WEEE and ELV is a UK wide activity and that the type
of waste and PBDE content of that waste would not be different by UK location. Sampling
effort was therefore focussed on the collection of samples from randomly selected ‘larger’
reprocessing sites that tend to accept a wider range of waste types rather than taking a small
number of samples from a large number of re-processors.
A higher proportion of samples were collected of shredded ‘single component’ WEEE rather
than whole single items. This approach ensured that the majority of samples were spot
samples taken from a large number of shredded units and the resulting test data is believed to
be a good representation of the wider UK waste stream.
2.1.2 Sampling exercise
Single visits were undertaken to a range of facilities which collect and bulk or shred, public
amenity waste collection sites and facilities that accept and reprocess shredded waste
streams. This approach provided a snap-shot (or spot samples) of the characteristics of these
wastes during February and March 2011.
The final sampling rationale was agreed following a meeting with Defra and is identified in
Figure 2.1. It was not possible to gain access to representative samples of ELV wastes during
the initial phase of testing and in the time frame of this report. However, a source of suitable
ELV samples has now been identified and sampling and testing are planned for
February/March 2012, the data from which will be reported in an Addendum to this report. The
samples collected were representative of two types of WEEE:
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‘Whole WEEE‘ - single whole components from WEEE awaiting re-processing – in this
instance the whole component e.g. an electronic razor or washing machine door catch
was prepared for testing; and
‘Shredded WEEE’ – single component waste from a generic WEEE category
e.g. casings from washing machines and videos where the component has been
separated and mixed for shredding. The samples from this stream represent pieces
from multiple items within the specified category.
Samples of WEEE were collected from four reprocessing sites as shown in Table 2.14.
Table 2.1 Details of samples collected for PBDE testing
Site Treatment type Materials Number of
samples
Date
sampled
Site A WEEE plastics TVs/ Computers/ small mixed WEEE/
and consumer items (e.g. coat-
hangers)
45 17/2/11
Site B Large WEEE/ELV
segregation
Printed circuit boards 20 22/2/11
Site C Small WEEE Computer equipment and telephones 10 23/2/11
Site D WEEE reuse/
reprocessor
White goods and small WEEE 25 8/3/11
By analysing whole components it was possible to establish the specific levels of PBDEs
associated with single items and specifically the proportions of different congeners. However,
analysis of single components is of limited use for assessing the levels of PBDEs in the UK as
a whole as a large number of items would need to be tested to obtain representative data.
Testing of shredded WEEE will provide such data. The shredded WEEE was commonly
stored in large bags or heaps that are a random snap-shot of the consumer waste streams
comprising more than 100 units. The shredding process serves to mix these components and
the incremental sampling procedure employed ensured a representative sample from the
primary heap. Preparation of the whole sample ensures the test data provides a reliable
average of the primary sample and larger number of units and increases confidence in
subsequent estimates about the wider population. This approach prevents range data being
gathered on an individual sample basis but allows estimation of a more reliable mean to be
derived for the number of samples taken.
4 WRc are currently arranging access to an ELV (polyurethane foam, textiles and ASR plastic)
reprocessing site to collect a range of samples, testing will be carried out using existing budget and
results will hopefully be available in early February 2012.
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Figure 2.1 Sampling approach for PBDEs in WEEE and ELV
Screen on site using XRF to determine which waste inputs
and output streams contain bromine – identify high, medium
and low items/streams
Confirm process inputs and priority process outputs during site
visit with process operators (to ensure information is accurate)
Submit 100 samples to primary contract lab for fine grinding
Submit draft final report to Defra
Stream 1 Stream 2 Stream X
Screen all samples on-site using XRF and select sub-set of
samples on-site for laboratory screening and testing
Select samples for laboratory testing on the basis of XRF
screening (high, medium, low Br) and sample source
Shredded single component WEEE Whole WEEE
Obtain figures on total tonnages of each WEEE waste stream
to derive the proportion of waste contaminated with PBDEs
figures for average and range of PBDEs in England and Wales
Collect and label whole items of single component WEEE.
Samples of shredded single component WEEE consisted of
at least 5 increments from either a falling stream on an
hourly basis over a 4 hour period or by taking at least 5
increments from a storage container
Commentary and justification of approach
Site Visits to collect wide range of WEEE
Determine range data for PBDE data
Identify range of
WEEE items
Plants selected to provide comprehensive range of WEEE. On-site discussion used to identify range of inputs and priority waste streams handled at each site with mass flow data where appropriate.
Screen all input and output field samples using triplicate XRF
measurements
Whole and shredded waste plastic and foam screened using portable XRF to identify detectable Br. On-site screening and sampling was focussed on waste items/streams with higher concentraions of Br as these wastes have the greatest impact on the variability of the final estimated mean PBDE concentrations. Where appropriate the age or serial numbers of high Br input items were noted. On-site screening was undertaken on approximately 300 samples using a single 30 second scan. All samples were returned to WRc.
Whole WEEE: selected low and high Br ‘whole components’ were collected for detailed screening at WRc (where possible individual components were tested separately to identify the source of Br). Selected components were sent to the test laboratory. Good laboratory practice was employed to ensure that the sample integrity was maintained.
WRc on-site activities
Shredded WEEE: Incremental samples were separately bagged for on-site screening and more intensive analysis at the WRc laboratory. A total of circa 100 samples would be returned to WRc using the XRF screening data to provide a range of Br concentrations. All bagged samples were screened in triplicate using the portable XRF. Those samples that exhibited high variability were un-bagged and selected items within the samples individually tested.
WRc laboratory activities
Greater emphasis will be given to samples with detectable Br concentrations to facilitate estimation of the correlation between XRF and GCMS and improved accuracy in range data for each PBDE group. Whilst the majority of samples were tested by the primary contractor using solvent extraction and High Resolution GCMS, a number were sent to a second test laboratory using Low Resolution GCMS to provide a measure of between laboratory variability (this will include all PUR samples). Testing will be scheduled to allow a basic estimation of between site, and between material variability.
Laboratories would both employ solvent extraction to maximise PBDE recovery. WRc would supply a QA specification to be followed by the test laboratory include use of internal standards, blanks, replicates and spiked samples. This approach will allow quantification of PBDE recovery and estimation of analytical method precision and confidence. PBDE congeners would include as a minimum: BDE-47 (tetra); -99 and -100 (penta); -153 and -154 (hexa); and -175 and -183 (hepta) as required by the Stockholm Convention. Additional congeners that are present C-Penta, C-Octa and C-Deca commercial products that are used in PUR, ABSand HIPS respectively would include: BDE -17 and 28 (tri); -196, -197 and 203 (octa); -206 and -207 (nona); and -209 (Deca).
Reporting
45 samples to be tested using HR-GCMS, in addition 10
samples were sent to a second laboratory for HR-GCMS for
QA purposes
All samples to be prepared at one laboratory to avoid introduction of bias using good laboratory practice to avoid cross-contamination.
Discuss report with Defra and obtain feedback
Submit final contract report to Defra
Activities
Overall Objectives: 1. Identify concentration of Stockholm BDEs by waste arising at national level. 2. Assess the feasibility of using XRF as an on-site screening tool to identify ‘PBDE contaminated’ products.
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The shredded WEEE was commonly <50 mm particle size and approximately 10 increments
were taken from either a falling stream across a five hour time period or at various positions
within a stockpile or holding bag to produce a 1 kg representative sample for testing.
This approach allowed an assessment of the levels of specific PBDE congener groups in both
individual components, and the production of average concentrations by waste stream.
2.2 Testing
2.2.1 XRFS Screening
This project was used to trial the application of XRFS as an on-site screening tool and to
calculate correlations with confirmatory laboratory analysis.
A portable X-Ray Fluorescence spectrometer (XRFS) can be used to provide a semi-
quantitative measure of total bromine in a sample. There are many variables affecting the
sensitivity of this technique which include the smoothness and density of the surface to be
tested, sample heterogeneity and total bromine content. A handheld Niton XL3t 700 unit was
used for this study. The limit of detection of the XRFS spectrometer for bromine is dependent
on the length of time a sample is scanned. A detailed plot to illustrate the change in the limit of
detection (LOD) with scan time is provided in Appendix A. A 30 second scan time provides a
LOD for total bromine of circa 5-10 mg/kg and equates to a detection limit of approximately
10 to 20 mg/kg for bromine containing compounds if we assume the compound contains
approximately 50% bromine (i.e. penta PBDE). The detection limit would be slightly better
with a higher level of compound bromination. The variability within a single piece of moulded
plastic was very low (<10%) and within the error of the spectrometer. The potential limitations
of XRFS include:
background levels of 40 mg/kg bromine have been recorded in many waste streams:
XRFS cannot distinguish PBDEs from other flame retardants containing bromine such
as hexabromocyclododecane (HBCD) dimethyltetrabromobisphenol A (MeTBBPA) and
polybrominated byphenyls (PBB); and
the technique cannot identify the level of PBDE bromination i.e. which congener groups
are present.
Each sample bag was initially scanned six times and an ‘average’ concentration recorded.
The XRFS unit reports concentrations for all elements with an atomic weight greater than
chlorine (therefore carbon, hydrogen and nitrogen are not determined). Instruments have a
pre-set factory calibration, and this was checked before and after use with a standard
reference disk, containing a known amount of bromine in a plastic matrix, supplied with the
instrument. The results for the reference disk remained consistent and within ± 5% of the true
value of the standard over the hire period of the instrument (two weeks). Using a 30 second
scan time the XRFS is capable of processing circa 12 samples per hour and therefore
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provides the opportunity to rapidly screen a large number of samples on-site and use this data
to select suitable samples for either further laboratory scanning or GCMS analysis.
On the basis of this data, selected samples were scanned in detail. Individual pieces of plastic
were scanned in a number of places, and the process completed across the entire sample to
produce a weighted average of the entire bag. Levels of bromine did not vary to any large
extent within each piece of plastic, a single scan was therefore subsequently taken of each
fragment, and this was taken to be representative of the whole piece. A total of 35 individual
components were screened by XRFS. In the samples selected for detail analysis upward of
80 pieces of plastic were scanned.
2.2.2 Sample selection for laboratory analysis
From the primary sample four sub-samples were produced during XRFS screening, according
to the following categories:
less than limit of detection (LOD) (approximately 5-10 mg/kg Br)
>LOD to 1000 mg/kg Br
1000 mg/kg to 5000 mg/kg Br
>5000 mg/kg Br.
These sub-samples provide a measure of within sample variability, which is in effect a
measure of the differences between component units. Whole samples provide a measure of
between sample variability.
Results from the XRFS screening were used to select the sub-set of 55 samples for
laboratory testing. The testing programme was developed to identify and quantify the PBDE
congeners present at both the bag level and for selected individual pieces to quantify the
relative amounts of PBDEs present in terms of the total sample to allow national grossing-up
of the data. Characterising the high and the low fractions separately allowed a more precise
estimate to be derived, and to relate the concentrations back to the original waste material.
2.2.3 GCMS analysis
The determination of PBDEs in WEEE and ELV plastic and foam matrices poses many
challenges. PBDEs are photosensitive and will degrade if exposed to sunlight or UV light and
care was taken to keep the samples stored in the dark as far as is possible. As the samples
have all been in environmental use prior to testing the results represent residual
concentrations of PBDEs in the waste plastics. No single UK laboratory was found that could
undertake the determination of full PBDE congener suites to the required limit of detection
(LOD) in both plastic and foam matrices, although a number have expertise in one or other of
these matrices. UK laboratories either had experience of testing sludge and soil matrices
using high resolution GCMS techniques (which offer the lowest LOD) or they routinely
analysed plastics but with a restricted congener suite and a poor LOD. None of the
laboratories had accreditation to relevant certification bodies for these matrices. The selected
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UK laboratory, Marchwood Scientific Services (MSS) undertook substantial method
development and validation to extend their existing sludge method to both plastic and foam.
The method relies on fine grinding of the sample to <1 mm particle size, followed by a 12 hour
soxlet based toluene extraction. Following vacuum rotary evaporation to reduce the solvent
volume to 1 ml the sample is purified on a 500 mg Silica SPE column and any PBDEs present
in the sample eluted with hexane. The analytical methodology used to undertake analysis of
plastic samples by MSS has been optimised for the determination of PBDEs in plastic
materials. Additionally the use of labelled internal standards allows concentration of PBDEs to
be determined using internal standardisation which allows recovery correction of PBDE data.
The use of internal standards eliminates the need for correction equations (or recovery
factors). This approach to analysis is established and applied in a wide range of analytical
applications. The method is capable of determining sub 0.05 mg/kg of individual PBDE
congeners in WEEE plastics (see Appendix A for full details).
A total of 45 samples were submitted to MSS for PBDE analysis. A further 10 samples were
submitted for analysis to the Fraunhofer Institute in Germany who have considerable
experience in testing these types of material to provide method comparison. All samples were
prepared by MSS. The test samples consisted of processing whole bag samples, processing
the sub-samples of the four bags of differing bromine concentrations produced during XRFS
scanning as detailed in Section 2.1.1 and finally specific individual pieces of plastic taken from
these bags. MSS took each of these samples and produced a fine ground powder from the
entire sample. The use of a specialist grinder (see Appendix A section A2.2 for details) to
undertake sample preparation avoided the production of excessive heat which can lead to
melting of the sample and degradation of PBDEs. Prepared samples were stored in dark
bottles to limit photo-degradation. The Fraunhoffer Institute confirmed that the appearance,
odour of the sample and PBDE fingerprints obtained on testing were consistent with samples
that had been appropriately prepared.
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3. Results
3.1 Introduction
The sampling programme targeted the main categories of waste electrical and electronic
equipment (WEEE) generated in the UK. Within the timeframe of the project it was not
possible to obtain samples for some of the minor categories of WEEE (see Table 1.1) or
arrange access to representative ELV waste streams. The samples collected and tested
account for >97% of all household WEEE produced in the UK. The samples collected from
selected collection and re-processing facilities are believed to provide a representative cross
section of WEEE waste being generated UK wide. The screening and analytical test data
therefore provides a useful initial data base on the concentration of PBDEs in UK WEEE.
XRFS: The XRF analysis was used to identify bromine containing waste which might be
indicative, of PBDE contaminated waste. Results are presented first from the XRF
screening in Section 3.2.
GCMS: Following selection of ‘bromine containing’ samples using XRFS, high
resolution GCMS was used to quantify the concentrations of specific PBDE congeners
in the sample. There are 209 possible congeners of PBDE compounds and reference
standards are not available for all of these. In line with standard practice target
congeners were chosen for this test programme for each of the brominated groups on
the basis that they are either widely accepted as being indicator compounds of the
common commercial preparations or they are known breakdown products from
commercially used PBDEs (e.g. nona-BDE is a breakdown product of deca-BDE). The
target congeners identified were matched to those commonly used in a range of
commercial C-Penta, C-Octa and C-Deca products. With the exception of octa-, nona-
and deca-BDEs the analytical suite included more than one congener for each PBDE
bromination group, reflecting those used in commercial products to provide a reliable
estimate of the ‘total’ PBDE concentration for each bromination group based on the
sum of the concentrations of only specified congeners. Table 3.1 lists the PBDEs
selected for testing. Results for the GCMS analysis are presented in Section 3.3.
3.2 XRFS screening
A portable XRFS can be used as an indicative and rapid screening tool to identify bromine
containing compounds. The XRFS provides a reliable measure of whether a sample contains
bromine. It cannot distinguish between inorganic and organic bromine, the type of brominated
compound (e.g. tetrabromobisphenol A (TBBPA) used in printed circuit boards or PBDE) or
differing levels of bromine substitution. The presence of bromine can, however, be used as an
indicator for the possible presence of PBDEs.
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Table 3.1 PBDE congeners analysed in GCMS analysis
Number Group Name
17 Tri 2,2',4-Tribromodiphenyl ether
28 Tri 2,4,4'-Tribromodiphenyl ether
47 Tetra 2,2',4,4'-Tetrabromodiphenyl ether
66 Tetra 2,3',4,4'-Tetrabromodiphenyl ether
71 Tetra 2,3',4',6-Tetrabromodiphenyl ether
85 Penta 2,2',3,4,4'-Pentabromodiphenyl ether
99 Penta 2,2',4,4',5-Pentabromodiphenyl ether
100 Penta 2,2',4,4',6-Pentabromodiphenyl ether
128 Hexa 2,2',3,3',4,4'-Hexabromodiphenyl ether
138 Hexa 2,2',3,4,4',5'-Hexabromodiphenyl ether
153 Hexa 2,2',4,4',5,5'-Hexabromodiphenyl ether
154 Hexa 2,2',4,4',5,6'-Hexabromodiphenyl ether
175 Hepta 2,2',3,3',4,5',6-Heptabromodiphenyl ether
183 Hepta 2,2',3,4,4',5',6-Heptabromodiphenyl ether
190 Hepta 2,3,3',4,4',5,6-Heptabromodiphenyl ether
203 Octa 2,2',3,4,4',5,5',6-Octabromodiphenyl ether
206 Nona 2,2',3,3',4,4',5,5',6-Nonabromodiphenyl ether
209 Deca Decabromodiphenyl ether
3.2.1 Whole WEEE – single component, single item
A range of selected electrical components were screened using the XRFS unit to determine
total bromine content. Over 300 different components were tested. The results of the XRFS
analysis are summarised in Figure 3.1. The results represent single samples of each of the
components and provide a crude snapshot of these waste streams.
The large majority (74%) of hard plastic components screened had a concentration of
<100 mg/kg bromine, with many components containing <20 mg/kg bromine. A small number
(12%) had a very high concentration of total bromine of up to 150,000 mg/kg (15% w/w). The
large range of bromine concentrations leads to an overall average of 11 000 mg/kg bromine,
although 85% of scanned samples had a lower concentration.
The value in this data is to provide a comparison with GCMS PBDE concentrations to assess
the practicality of using XRFS as a PBDE contamination screening tool rather than the
concentrations detected in each item.
The types of components that contained bromine at significant (>1 % w/w) concentrations
tend to be plastics associated with electrical components (covers, printed circuit boards,
switches etc.). These levels are presumed to be indicative of primary PBDE added at the
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0
10
20
30
40
50
60
70
Fre
qu
en
cy
Bromine concentration (mg/kg)
point of manufacture, at levels which commonly exceed 5%. A number of materials contained
medium levels of bromine, this is thought to be associated with PBDEs added during the
manufacture of new products in process that utilise recycled plastics containing PBDEs.
Figure 3.1 Concentration of bromine in selected electrical components by portable
XRFS unit
Results of scanning over 300 individual components of WEEE from large household appliances, refrigerators and
small WEEE
3.2.2 Shredded WEEE – single component, multiple items
Detailed scanning has identified a typical fingerprint for XRFS bromine in shredded WEEE. A
typical histogram for shredded plastic from computer monitor casings is provided in Figure 3.2
for scan results on individual pieces in sample A17. This data is typical of that produced for
other waste streams. Many of the plastic pieces show two distinct concentration ranges 1).
less than 500 mg/kg and 2) >5000 mg/kg bromine. The greatest proportion of readings was
found in the first group with the majority of readings at much lower levels, some 66% around
5 mg/kg bromine. A small number of samples had a very high total bromine concentration of
>100 000 mg/kg. Sixty-six percent of the samples had <10 mg/kg total bromine. Analysis of
the data for individual samples shows that whilst the average bromine concentration for this
sample was 15 000 mg/kg, this is influenced by a small number of plastic pieces that had
extremely high values.
Although the average concentration is an important outcome of the testing, to test the
usefulness of XRFS as a screening tool test samples were split into indicative bromine
concentration ranges, as described in Section 2.2.1 and the categories generated were then
analysed by GCMS to provide a comparison between the two techniques. Sample A17 was
tested in this way. The XRFS and GCMS data are presented in Figures 3.2 and Figure 3.3.
These sub-samples provide a measure of within sample variability, which is in effect a
74% very low total bromine
14% medium total bromine
12% high total bromine
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measure of the differences between component units. Whole samples provide a measure of
between sample variability. The high level of within sample variability shows the importance of
robust sampling procedures for these waste streams.
Figure 3.2 Plot showing range of concentrations of Br in samples of computer
casings by XRFS
3.3 GCMS analysis
The analytical methodology used to undertake analysis of plastic samples by MSS has been
optimised for the determination of PBDEs in plastic materials. Additionally the use of labelled
internal standards allowed concentration of PBDEs to be determined using internal
standardisation which allows recovery correction of PBDE data. The use of internal standards
eliminates the need for correction equations (or recovery factors). This approach to analysis is
established and applied in a wide range of analytical applications. The method developed by
MSS for the determination of PBDEs in plastics requires the assessment of PBDE recovery
from a matrix sample to provide full method validation (a ‘blank’ or low PBDE plastic reference
sample could not be obtained within the timeframe of the method development activities but
this will be addressed if further testing is required). Criteria for acceptance of calibration
samples (including a standard reference material) and internals standard recovery have been
agreed for future testing.
Five samples were tested by both MSS and the Fraunhofer Institute in an interlaboratory
comparison trial to judge the validity of the new test data (Appendix B4). The test data for
sample S10 ‘High’ showed poor correlation between the two laboratories and this could be
0
5
10
15
20
25
30
0 5 20 500 1000 5000 100000 200000 More
Fre
qu
en
cy
Br concentration (mg/kg)
Medium (11%) Low (66%) High (23%)
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attributed to sample heterogeneity at even the small particle scale (XRFS analysis indicate a
wide range in concentrations between individual plastic pieces in this sample). Results from
MSS are also consistently higher than Fraunhofer’s for three congeners: 183, 154 and 100.
However, if these three congeners and the S10 ‘High sample’ are excluded, there is a fair
measure of agreement between the laboratories (Table B.8).
The most prevalent congener of PBDE found in all test samples was deca BDE-209, which
accounted for 85% of all PBDEs detected. Deca BDE-209 is not a listed Stockholm
compound. This does mean that XRFS screening could give false positives where the
presence of bromine is used as a presumptive indicator for listed PBDEs.
3.3.1 Whole WEEE – single component, single item
Components that did contain significant levels of bromine using XRFS were submitted for
analysis by GCMS, to quantify concentrations of PBDEs. The results are summarised in
Figure 3.3. The sum of the target congeners selected for this programme, which are those
predominately used in commercial formulations have been used to provide a measure of the
total concentration of each listed brominated BDE group.
Figure 3.3 PBDE concentrations in various whole electrical components taken from
UK waste sites
The blue diamonds represent calculated total PBDE concentrations for each congener suite
for each WEE category. The concentrations for each WEEE category should be taken from
the right hand axis and are in decreasing concentration of total PBDE from left to right. The
histogram style bars illustrate the proportion of individual PBDE groups in terms of the total,
as measured by the sum of the each target congener suite. The proportions of each congener
0
10000
2000030000
4000050000
60000
7000080000
90000
0.0%10.0%20.0%30.0%40.0%50.0%60.0%70.0%80.0%90.0%
100.0%
Tota
l PB
DE
(mg/
kg)
Pro
po
rtio
n P
BD
E co
nge
ne
r
deca
nona
octa
hepta
hexa
penta
tetra
tri
Total PBDE
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are presented on the left hand axis. For example, a TV unit contained over 83,820 mg/kg total
PBDE which consisted of 5.8% (4800mg/kg) hexa, 27.4% (23,000 mg/kg) hepta, 5.1% (4300
mg/kg) octa, 0.9% (720mg/kg) nona, 60.7% (51,000) deca PBDEs. The raw data on PBDE
concentrations in individual samples is provided in Table B.2 in Appendix B.
The data are for single examples of each WEEE component type and should not be
considered to be representative of UK waste arisings but are useful to illustrate the
differences in congener groups and total PBDE concentrations in different WEEE categories.
The dominant PBDE congener is clearly deca-BDE (as measured by deca-209), which is still
in legitimate use. Only one sample from a TV casing contained significant levels of hepta- and
octa-BDE groups. This sample also contained high levels of deca-BDE (87% of the total
PBDE concentration). This observation is consistent with data for shredded WEEE. The
GCMS data provides sound evidence that mixes of PBDE congeners and bromination groups
are used in components rather than one specific congener. Low levels of ‘listed PBDEs were
seen in all samples. This low level contamination could be attributed to the proportion of
recycled plastic in the component tested. Of the 45 samples of whole and shredded samples
tested, none contained below detection limit levels of Stockholm-listed PBDEs.
3.3.2 Shredded WEEE – single component, multiple items
The GCMS data confirms that XRFS is effective in identifying component pieces within a
waste stream that contain bromine. In the majority of samples then tested by GCMS
detectable XRFS bromine could be matched to quantifiable levels of PBDEs in WEEE items.
Low XRFS bromine could be specifically linked to low PBDE concentrations by GCMS and
specifically listed PBDEs. Figure 3.4 illustrates the differing concentrations of PBDEs in a
single sample prepared from a large number of pieces of computer cases from multiple units.
The PBDEs in the shredded components are dominated by nona- and deca-BDE congeners.
Ten samples were submitted for GCMS testing each consisting of circa 80 pieces from
different units. The samples are therefore considered to be representative of the wider UK
waste stream.
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Figure 3.4 Plot showing PBDE concentrations in a bulk sample of shredded
computer casings
Figure 3.5 provides the same data but excludes nona- and deca-BDEs. Although the ‘high’
sample still has the largest proportion of BDEs, the difference in concentrations of the other
PBDE bromination groups is much less marked. The ‘high’ sample has over 1000 times the
concentration of total BDEs compared to the ‘low’ sample, whereas it only has four times the
concentration of BDEs that are not nona- or deca-. This would seem to indicate that these
groups are present due to the addition of recycled plastic waste containing non nona- or deca-
PBDEs rather than they have been added at percentage levels to provide flame retardant
properties. GCMS concentration data by PBDE congener is provided in Table B2 in
Appendix B.
0
2000
4000
6000
8000
10000
12000
14000
16000
A17 High A17 Medium A17 Low
Tota
l PB
DE
(mg/
kg)
deca
nona
octa
hepta
hexa
penta
tetra
tri66% 11% 23%
Very small
proportion of
PBDEs that are
not nona- or
deca- BDE in all
three fractions
Defra
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© WRc plc 2012 25
Figure 3.5 Plot showing PBDE concentrations in bulk sample (A17) of shredded
computer casings excluding nona- and deca-BDE
Figure 3.6 details the test data for a sample of TV casings, consisting of 80 plus pieces of
different shredded units. Very low levels of PBDE were detected in the medium and low
samples separated by XRFS screening.
Figure 3.6 Plot showing PBDE concentrations in sample (A28) - television casings
0
5
10
15
20
25
30
A17 High A17 Medium A17 Low
PB
DE
con
cen
trat
ion
(m
g/kg
)
octa
hepta
hexa
penta
tetra
tri
tetra seen in medium stream
Difference between
high and low fraction
much less pronounced
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4. Discussion
4.1 PBDEs in UK WEEE
Samples collected for this study represented the following categories of WEEE: large
household appliances, lighting equipment and small household appliances (all single items
from single units only), IT and telecoms equipment, consumer equipment, display equipment
and cooling appliances containing refrigerants. These categories represent 97% of the total
weight of WEEE collected in the UK (Table 1.1)5. Range data for the indicator PBDE
congeners is presented in Table 4.1. In deriving range data the test data has been assumed
to be log-normally distributed, which is supported by the data analysis in Appendix B3.
Table 4.1 Unweighted range data (GCMS) for PBDEs Waste electrical and electronic
equipment (WEEE)
Material No.
Range data for PBDEs for WEEE categories (mg/kg)
tri tetra penta hexa hepta octa nona deca
TVs 7 <0.001 -
21
0.005 -
2100
0.01 –
4410
0.03 -
14000
0.1 -
36500
<0.001 -
1880
<0.001 -
901
21 -
138000
Industrial IT
equipment 5
0.0029 -
25.4
0.0002 -
254
0.0004
– 435
0.001 -
1210
0.0047 -
5960
<0.001 -
47.7
0.0106 -
625
0.162 -
32400
Printed circuit
boards 2 1.3 - 2.4
5.93 -
11.2
6.97 –
16
307 -
582
2790 -
5230
<0.001 -
173
268 -
638
42500 –
129000
Digiboxes 4 0.0002 -
2.28
<0.001 -
215
0.0035
– 462
0.009 -
1470
0.03 -
4990
<0.001 -
1690
<0.001 -
288
4.4 –
5720
Large
household
appliances
13 0.0005 -
6.5
0.0071 -
14.2
0.042 –
65
0.138 -
308
0.178 -
3850
<0.0005
- 426
<0.0005
- 790
912 -
45700
Small WEEE 1 0.37 3.2 5.1 8 41 5.43 5.51 778
Coat hangers
4 0.002 -
0.76
0.03 -
3.45
0.06 -
5.61
0.1 -
74.9
0.725 -
3440
<0.001 -
645
0.1 - 288 22 –
80400
Fridges 2 0.3 - 0.5 0.5 - 3.2 1.6 - 4.5 11 - 14 <0.001 -
44.5 4.2 - 6.4
12.2 -
28.3 79 - 155
PC monitors 4 0.01 -
0.08
0.129 -
0.556
0.209 -
1.05
0.8 -
3.07 4.7 - 20
<0.001 -
2.79
0.163 -
490 6 - 13900
Stockholm Annex listed PBDEs
5 The 3% of WEEE not captured in this study includes electrical and electronic tools, toys, leisure and
sports; gas discharge lamps; monitoring and control instruments; medical devices; lighting
equipment; and automatic dispensers.
Defra
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© WRc plc 2012 27
The table is colour coded by congener – the highest concentration seen for each congener is
coloured red, through orange to green for the lowest concentration. For example, for hepta-
BDEs, the highest concentration was seen for IT equipment, and the lowest for PC monitors.
The data provides an initial estimate of the PBDEs in the UK WEEE waste stream. The
ranges are wide and this is a reflection of high within sample variability and where we have
tested low, medium and high material (as screened by XRFS) separately. This shows the
importance of collecting samples that consist of a large number of shredded pieces and which
are representative of multiple units to avoid bias.
Weighted average PBDE concentrations for each congener by WEEE stream are shown in
Figure 4.1. The concentrations are derived from the weighted average of the GCMS data for
each of the ‘high’, ‘medium’ and ‘low’ fractions (as defined by XRFS screening) as a
proportion of the overall sample to give an overall concentration for each of the categories.
Household appliances have not been included in this plot as data is only available for a limited
number of single pieces from a small number of individual units.
Figure 4.1 Plot showing PBDE concentrations in shredded bulk WEEE samples
As with previous plots the proportion (left hand axis) of each PBDE group is shown by the
bars, and the total concentration of PBDEs (right hand axis) shown by the red diamonds. The
highest concentration of total PBDEs were found in printed circuit boards (PCBs), TVs and IT
equipment. The most frequently detected congener present in the highest concentrations was
209-deca BDE. Significant proportions of hepta-BDE were also seen in TVs, IT equipment
and digiboxes. The number in brackets (x axis) represents the number of samples tested for
each component type. Testing of the ‘low’, ‘medium’ and ‘high’ sub-samples produced from a
single sample is counted as a single sample. Although a relatively small number of samples
were tested in total each sample consisted over 80 pieces and is considered to represent
greater than 100 individual units. Table 4.2 provides this range data in tabular form, the
Defra
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© WRc plc 2012 28
ranges are much tighter but overall sample numbers need to be increased to improve data
certainty. Note where only one combined sample has been tested the figure quoted is a
minimum value.
Table 4.2 Weighted range data (GCMS) for PBDEs Waste electrical and electronic
equipment (WEEE)
Material No.
Weighted average range data for PBDEs for WEEE categories (mg/kg)
tri tetra penta hexa hepta octa nona deca
TVs 2 2.5-3.3 6.6-338 13.0-
707
273-
2251
2051-
5852 168-302 145-168
8446-
37419
Industrial IT 1 14.9 149 255 711 3495 9.9 372 21486
Printed circuit
boards 2 1.3-2.4 5.9-11.2 7.0-15.1
307-
582
2785-
5231 0.0-173 268-638
42481-
129045
Large HH
appliances¹ 6 0.0-1.8 0.0-7.4 0.0-30.0
0.1-
310.0 1.0-3800
0.0-
430.0 0.0-180
910-
46000
Digiboxes 1 0.4 25.9 55.5 176 601 203 34.7 855
Small WEEE 1 0.4 3.3 5.1 8.0 41.0 5.4 5.5 778
Fridges 1 0.4 1.8 3.0 12.2 22.2 5.3 20.2
PC monitors 2 0.0-0.0 0.2-0.4 0.3-0.8 1.5-2.6 9.2-13.6 0.8-2.8 15.7-116 3488-
7998
Stockholm Annex listed PBDEs
Note: ¹ 6 items from 6 individual units
Weighted average data for Stockholm listed POPs (tetra-, penta-, hexa- and hepta-PBDEs)
along with total PBDE concentrations are presented in Table 4.3. These concentrations are
derived from the weighted averages of the ‘high’, ‘medium’ and ‘low’ fractions and bulk
samples that were tested as a whole sample.
As in previous tables, the table is colour coded, showing highest concentrations in red,
through orange to green for the lowest concentrations. It can be seen that in general, high
concentrations of total PBDEs are correlated with the Stockholm list of PBDEs. A notable
exception to this is the PC monitor category where the majority of PBDEs present in this
material are nona and deca congeners. Data for large household appliances should be
viewed with extreme caution as it is based on a small number of component parts from
individual units rather than a sample that represents a large number of shredded units
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Table 4.3 Weighted average concentrations of the sum of Stockholm listed PBDEs
and total PBDEs by WEEE stream
Category Average total tetra, penta,
hexa, hepta- PBDE (mg/kg)
Average total PBDE
(mg/kg)
TVs 5746 90777
Industrial IT equipment 4610 29073
Printed circuit boards 4473 26493
Digiboxes 858 5825
Large household
appliances 762 16945
Small WEEE 57 847
Fridges 39 182
PC monitors 14 12353
Sum of Stockholm listed PBDEs
Sum of total PBDEs
(listed and unlisted)
The key implications of the data for each WEEE category, presented in Tables 4.1 to 4.3 are
summarised in word form in Table 4.4, but the following main conclusions can be drawn:
Listed PBDEs were detected in all WEEE tested, if as we believe, the ‘snapshot’
samples tested are representative of the wider UK wide WEEE stream (each sample is
representative of some 100 units) this points to a widespread issue for future waste
management practice.
The concentrations of listed PBDEs vary substantially by WEEE stream. Fridges, larger
household appliances and PC monitors generally have lower concentrations than TVs,
industrial IT equipment, printed circuit boards and digiboxes.
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Table 4.4 Summary PBDE data for WEEE
Number Findings
Fridges Concentrations of all PBDEs were quantifiable but lower than in most
waste plastic streams. All Stockholm Annex listed PBDEs were
detected by high resolution GCMS. The levels of deca-BDE were x5
those of the Stockholm list.
Large household
appliances
Although 85% of samples scanned by XRFS contained no or low levels
of bromine, many components from large household waste appliances
were found to contain significant levels of deca-BDE. Some samples
were also found to contain medium levels of hepta-BDEs.
PC monitors The vast majority of BDEs detected by GCMS were deca-BDEs. PC
monitors were found to have medium levels of deca-BDE and low levels
of all other congeners, despite having some of the highest levels of
bromine by XRFS scanning. This raises the possibility that there may
be other brominated flame retardants present in these samples, as
much of the bromine observed in XRFS cannot be accounted for by the
PBDE test data.
TV TV casings contained some of the highest levels of hepta-BDEs and
high levels of many of the lower substituted congeners. TVs had the
highest levels of deca-BDE.
IT equipment High concentrations of most PBDE congeners, with some of the highest
levels of Stockholm list tetra- and penta-BDEs in any waste category.
High levels were found in many different component fractions.
Digiboxes Medium to high levels of PBDEs were observed for most bromination
groups, 11% of all samples had a bromine concentration of >1%. The
observed concentration of the Stockholm list BDEs other than deca
were in the medium range, suggesting they have been added via plastic
recycling as they would be present at much higher concentrations if
they were being added specifically as flame retardants.
Small WEEE Low levels of all BDEs were found in this single sample of WEEE.
Printed circuit
boards
High levels of bromine were found in >95% of samples, much of which
is likely to be present as TBBPA. However, the samples also contained
very high concentrations of nona-, deca-BDEs.
Coat hangers Coat hangers contained medium-low levels of all PBDE congeners.
Very high levels of deca-BDE were found in some samples.
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4.2 Estimates of PBDEs in UK Waste stream
WRc have used the weighted average data presented in Table 4.3 to calculate estimates of
the total quantities of Stockholm listed PBDEs in the UK WEEE stream, these are presented
in Table 4.5. Published Environment Agency data on UK waste arisings (total tonnes by
specified WEEE categories - Table 1.1) has been combined with the mean concentration
value for PBDEs in each stream (Table 4.4) and data on the percentage of brominated
plastics by total unit weight (Empa - Table 1.2) to produce a gross estimate.
Confidence limits have been estimated for the derived weights of PBDEs in UK WEEE. The
confidence limits assume that samples have been chosen randomly and that the published
data for UK waste arisings and the weight of brominated plastics in consumer items are
correct.
Current estimates of the quantities of listed PBDEs in WEEE suggest that effective measures
for separation of PBDE contaminated components would be most beneficial for large
household appliances and the ICT and consumer electronics category. The data set for large
household items is limited by the fact that the samples tested represent single items from
single units and the sample may not be representative of the wider UK waste stream. The
large weight of total arisings for this waste stream, and potentially high levels of listed PBDEs
associated with some individual components mean that it could provide a substantial
proportion of the total listed PBDEs in UK WEEE. Further sampling is recommended to
reduce uncertainty in PBDE concentrations in this waste stream. Within the ICT stream it has
been necessary to combine TVs and PC monitors which have quite different PBDE profiles
and concentration ranges. A more detailed assessment is required for individual target sub-
categories to provide more reliable estimates of the quantity of listed PBDEs in UK WEEE.
The estimates provided in Table 4.5 are based on a relatively limited number of samples of
UK WEEE (at the aggregated ‘whole’ sample level) and should be used with caution and with
due consideration of the following assumptions and facts.
Estimated percentage weights of brominated plastics versus the total weight of each
WEEE component unit (Empa) are only available for the following gross categories:
large household appliances, small household appliances and ICT and consumer
electronics. In the production of grossed estimates it has therefore been necessary to
assume that the percentage weight of brominated plastics as a proportion of the total
weight remains constant for each of the combined sub-categories (e.g. ovens, tumble
driers, dish washers) within each overall category (large household appliances) etc.
Data on the weight of plastic components containing PBDEs within each sub-category
is required to reduce grossing errors.
Data on the quantity of PBDEs as a percentage of the total weight of brominated
plastics is also not currently available. Brominated plastics include PBDE, TBBA and
PBB, but for the purpose of the current estimation exercise it has been assumed that
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the quoted weight of brominated plastics (Empa) are all PBDEs. The gross estimate
therefore represents a maximum. Data on the weight of brominated plastics as a
percentage of the total weight of plastic is not available for cooling appliances and it
has been assumed that the weight percentage of brominated plastics is greater than
other large household appliances but lower than ICT and a figure of 10% has been
adopted.
WEEE sub-categories have been combined into four overall categories for which data
on waste arisings and levels of brominated plastics are available. The gross categories
therefore contain a wide variety of materials and components which, on the basis of this
study for Defra can have different levels of PBDE contamination. Waste arisings data
at a more detailed level would improve the accuracy of any estimation of PBDEs in the
UK waste stream.
The sampling approach was developed on the working assumption that X-Ray
fluorescence spectrometry screening would show that the majority of plastic pieces
(each representing a unit) would not contain PBDEs and that certain waste streams
could be excluded from the gas chromatography mass spectrometry (GCMS) analysis.
This would have meant that a larger number of samples could be tested within selected
component waste streams to increase certainty in the range data produced. In the
event the screening showed that there is low level contamination from tetra-, penta-,
hexa- and hepta-BDEs across all target WEEE and that a significant proportion are
present at a higher level of contamination most probably due to mixing of contaminated
recycled plastics in new products and it was therefore necessary to spread the
available GCMS testing resource across all component streams. The range of data for
each congener group is wide and the number of samples in each category smaller than
was originally intended and this hinders any attempt to estimate the quantities of
PBDEs in the overall UK waste stream with acceptable certainty. The accuracy of the
range data is limited by the variability within and between samples and the relatively
small number of ‘whole’ samples tested in each category. Collection of additional
samples in key target categories would improve this situation.
Specifically the overall estimates would be substantially improved if the number of
samples in each category was increased by further sampling and testing, ideally to
make the total number of samples in each category up to 12 to allow the corresponding
distributions of PBDE concentrations to be estimated: i.e. confirmation of log-normality,
and summary statistics including the mean, variance and upper and lower percentiles
to be calculated. There is some scope for reducing the sample numbers down to a
minimum of say eight per material, at the cost of greater uncertainty in the estimates.
Further examination of the test data to further determine the correlations between
congener concentrations, and between the GCMS and XRFS results could be used to
gain the maximum information from sampling and analysis at minimum cost. High
correlations imply scope for analysing a small number of parameters and estimating the
values of other parameters.
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Within sample variability is high and it is therefore critical that a large and well mixed
sample is collected for analysis to keep differences in the PBDE concentrations of
individual component units biasing the mean.
The total concentration of Stockholm listed PBDEs in each bromination group is based
on summing a relatively small number of indicator congeners, which are present as the
main constituents in commercial PBDE preparations. Low levels of other congeners
may be present and these will not be accounted for using this approach.
The analytical methodology used to undertake analysis of plastic samples by MSS has
been optimised for the determination of PBDEs in plastic materials and the use of
labelled internal standards allows concentration of PBDEs to be determined using
internal standardisation which avoids the need for recovery correction of PBDE data.
Whilst this approach to analysis is established and applied in a wide range of analytical
applications additional quality assurance is required to fully validate the test method.
The test samples and detected levels of PBDEs are considered to be a representative
snapshot of UK WEEE, with the exception of large household appliances and some
individual consumer products e.g. a razor the majority of test sample contain upward of
100 component units.
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© WRc plc 2012 34
Table 4.5 Estimated weights of Stockholm listed PBDEs in key UK WEEE streams
Waste Category
UK Arisings Data
2010
Brominated
plastics in waste
(Empa)
No.
Sample
Mean PBDE concentrations in UK test
samples (mg/kg)
Estimated wt. Stockholm
listed PBDEs UK WEEE
tonnes % % tonnes tetra penta hexa hepta
Total
Stockholm
listed
PBDEs
Best
estimate
Lower
limit
(5%ile
Upper
limit
(95%ile)
Large household
appliances 141,236 31.0 0.29 410 6 2.9 7.4 63.9 688.0 762.2 0.312 0.067 0.817
Cooling appliances 97,414 21.0 10.0 9,741 1 1.8 3.0 12.2 22.2 39.3 0.010 0.003 0.022
Small household
appliances 22,870 5.0 0.75 172 1 3.3 5.1 8.0 41.0 57.4 0.003 0.001 0.009
ICT & consumer
electronics 186,435 40.0 18.0 33,558 9 71.1 136.5 519.3 2413.4 3140.2 123 53 242
Other waste (not
sampled) 13,265 3.0
Total 461,220 100.0
Note:
Single pieces from 6 items.
Bulk sample from multiple shredded units.
Empa do not provide a figure for the level of brominated plastics in cooling appliances, WRc have assumed that it is higher than other large household appliances due to the plastic internal construction of a fridge or freezer but less than ICT where the outer frame consists of brominated plastic.
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5. Conclusions and Proposals
5.1 Overview of PBDE congeners in UK WEEE
Consistently low, with respect to flame retardant effect, but detectable levels of listed PBDEs
were seen in all items tested. Since it is believed that these samples are representative of
wider UK WEEE, this equates to widespread listed PBDE contamination across this stream.
The presence of listed PBDEs is usually, but not always, associated with higher and more
variable concentrations of nona-and deca-BDEs. Nona-206 and deca-209 BDEs are the
dominant PBDEs found in both single component waste electrical and electronic equipment
and shredded waste electrical and electronic equipment consisting of multiple components.
Both nona and deca PBDEs are still routinely used as flame retardants in manufacturing, but
neither are listed persistent organic pollutants.
Estimates have been made of the proportion of waste contaminated by Stockholm Convention
listed PBDEs for the UK waste stream (Table 4.5) but these should be viewed with caution for
a number of reasons:
Firstly, data on waste arisings are only available at an amalgamated level for generic
categories e.g. the category ‘display equipment’ contains both TV and PC monitors that
have differing PBDE characteristics. The proportion of the total weight of the PBDE
containing components requires further verification and in some cases this data is not
currently available.
Secondly, the sampling approach was developed on the working assumption that X-Ray
fluorescence spectrometry screening would show that the majority of plastic pieces (each
representing a unit) would not contain PBDEs and that certain waste streams could be
excluded from the gas chromatography mass spectrometry (GCMS) analysis. This would
have meant that a larger number of samples could be tested within selected component
waste streams to increase certainty in the range data produced. In the event the
screening showed that the majority of the data shows that that there was detectable
contamination across all target waste electrical and electronic equipment and it was
therefore necessary to spread the available GCMS testing resource across all
component streams. The range of data for each congener group is wide and the number
of samples in each category smaller than was originally intended and this hinders any
attempt to estimate the quantities of PBDEs in the overall UK waste stream with
acceptable certainty. Specifically the estimates of listed PBDE in UK waste electrical and
electronic equipment would be substantially improved if the number of samples in each
category is increased by further sampling and testing to allow the corresponding
distributions of PBDE concentrations to be estimated: i.e. confirmation of lognormality,
and summary statistics including the mean, variance and upper and lower percentiles.
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5.2 Levels of listed PBDEs in waste electrical and electronic equipment
The significant concentrations of listed PBDEs in printed circuit boards, TVs and industrial IT
equipment are such that may exceed future EU limits. This is of major significance if we
consider that the contribution of IT equipment and TVs is circa 34% of the total UK waste
electrical and electronic equipment stream and potentially poses a significant problem to
waste electrical and electronic equipment recycling in the UK. Management measures may be
needed to remove contaminated material prior to re-processing. The PBDE concentrations
detected in all the waste electrical and electronic equipment streams tested in this study
would fail to meet proposed lower limits for some PBDE bromination groups.
Of the listed PBDEs, hepta-BDE and to a lesser extent hexa-BDE appear to be the
predominant listed contaminants, particularly in TVs, IT equipment (PC monitors) and
digiboxes. Each sample of shredded waste electrical and electronic equipment tested by
GCMS is representative of at least 100 units, although the number of samples tested in
relatively small, 42 in total (and smaller within each waste stream) the data is believed to
provides a representative snap-shot of each waste stream.
The concentrations of listed PBDEs vary from < 1 - 36,500 mg/kg but are generally below
5000 mg/kg. This concentration is too low to be effective as a flame retardant and it is
believed that these plastic items have been contaminated through incorporation of plastic
recyclate containing listed PBDEs into new manufactured products. This suggests that
although dilution of listed PBDEs will occur during repeated recycling, it will take a
considerable time to eradicate these substances from the WEEE stream unless measures are
put in place to remove them prior to re-processing or the process has a suitable separation
stage. From the initial findings of this study it could be a number of decades before the UK
might expect to see PBDE free consumer goods being discarded.
5.3 Levels of PBDEs in ELV
Samples will be collected in January 2012 to address the gap in new data for ELV. Data will
be reported to Defra as a supplementary Annex to this report.
5.4 PBDE Quantification by High Resolution GCMS
A PBDE test method was developed to support this programme of work. Despite extensive
method development the determination of PBDEs in plastic and foam matrices continues to
be a challenge, although a UK laboratory is now in a position to test for target PBDEs in the
plastic from waste electrical and electronic equipment. However, the technique requires a
specialist laboratory, a multi-stage sample preparation and extraction procedure and high
resolution GCMS to test the final sample. The method is capable of determining sub
0.05 mg/kg of individual PBDE congeners in waste electrical and electronic equipment
plastics. However, the complexity, and cost of the test, means it is not a tool that is applicable
to routine process monitoring nor indeed is this method likely to be suitable for routine
regulatory testing. The analytical methodology used to undertake analysis of plastic samples
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by MSS has been optimised for the determination of PBDEs in plastic materials. Additionally
the use of labelled internal standards allows concentration of PBDEs to be determined using
internal standardisation which allows recovery correction of PBDE data. The use of internal
standards eliminates the need for correction equations (or recovery factors). This approach to
analysis is established and applied in a wide range of analytical applications. The results from
the UK laboratory were successfully correlated with test data on a selected number of
samples to a European test facility which has considerable experience of testing WEEE
matrices.
5.5 Suitability of XRFS as a screening tool
XRFS provides a rapid technique for the assessment of total bromine in ELV and WEEE. The
limitations of the test arise from the fact that it cannot distinguish between PBDEs and other
bromine containing compounds or determine which PBDEs are present in the sample i.e.
whether the PBDEs listed in the annexes of the Stockholm Convention on Persistent Organic
Pollutants are present. This aside with the exception of printed circuit boards which are known
to contain tetrabromobisphenol A, the correlation between XRFS data and GCMS indicates
that PBDEs appear to be the primary bromine containing compound in other WEEE. Many of
the samples tested provide low <100 mg/kg total bromine but this could be consistently linked
to low concentrations of listed PBDEs, Such low concentrations of PBDE have little value as
flame retardants and it is concluded that this is consistent with recycling of listed PBDEs in the
waste plastic stream into new products. Conversely where bromine concentrations exceeded
1% w/w whilst the majority of this could be attributed to non-listed PBDEs that are legitimately
being added during manufacture low levels of listed PBDEs are also present. We conclude
that XRFS can be used as a crude but effective screening tool to identify WEEE and ELV
containing bromine and potentially PBDEs. The results of this relatively limited study suggest
that a positive XRFS bromine result provides a good indicator measure for the presence of
listed POPs. In particular very low total bromine concentrations (<500 mg/kg) are often linked
specifically to listed PBDEs.
5.6 Proposals for further work
The authors suggest that the precision associated with PBDE concentrations in the
current dataset could be improved by testing additional samples. Further analysis is
recommended of the key waste streams identified as contributing significant quantities
of listed PBDEs to the UK waste stream i.e. large household appliances and ICT and
consumer electronics. This is either because they contain high listed PBDE
concentrations or they form a substantial proportion of WEEE arisings. WRc already
hold a number of additional samples of TVs, PC monitors and digiboxes in the ICT
category that have not been tested by GCMS, but further sampling would be needed to
acquire shredded large household appliances as single items were only available for
the current study. A minimum of 8, but ideally 12 samples should be tested for each of
these categories. Further testing will improve both the weighted average and reduce
uncertainty in any grossing up estimates.
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A detailed breakdown of UK waste electrical and electronic equipment arisings is
required at a finer level to allow derivation of more accurate gross estimates for PBDEs
in UK WEEE. Combining categories such as TVs and PCs, which have different list and
non-listed PBDE concentrations and congener profiles will not lead to accurate
grossing data. Further corroborated data is required for the percentages of PBDE
containing components in some WEEE categories e.g. cooling equipment. Similar data
is required for ELV.
The current study has provided valuable information on the levels of PBDEs in the UK
WEEE stream, and it is hoped that samples of ELV will be available for testing in the
January 2012.
These sub-samples provide a measure of within sample variability, which is in effect a
measure of the differences between component units. Whole samples provide a
measure of between sample variability. The high level of within sample variability
shows the importance of robust sampling procedures for these waste streams.
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References
DIRECTIVE 2002/95/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 27 January
2003 on the restriction of the use of certain hazardous substances in electrical and electronic
equipment.
DIRECTIVE 2002/96/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 27 January
2003 on waste electrical and electronic equipment (WEEE) Official Journal of the European Union
13.2.2003.
REGULATION (EC) No 850/2004 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 29
April 2004 on persistent organic pollutants and amending Directive 79/117/EEC.
WRAP (2005) The Waste & Resources Action Programme, Develop a process to separate brominated
flame retardants from WEEE polymers - Interim Report 2, 20 August 2005, ISBN: 1-84405-147-1.
Stockholm Convention (2009) UNEP Stockholm Convention on Persistent Organic Pollutants (2009):
Revised draft risk profile: short-chained chlorinated paraffins. 9 November 2009.
European Commission (2010) Study on waste related issues of newly listed POPs and candidate
POPs.
WRc (2011) Sampling plan for assessment of PBDEs in WEEE streams.
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Appendix A PBDE Method Development
A1 XRFS Scanning
A1.1 Scan time
A handheld Niton XL3t 700 XRFS (X-Ray Fluoresence Spectrometer) was selected for the
determination of total bromine in the plastics samples. The unit works by placing the sample
in front of the X-Ray beam for a selected scanning period to determine the total bromine
content of the sample. The error associated with each reading is inversely proportional to the
length of time the sample is scanned. The plot in Figure A.1 shows this error decreases with
the amount of time taken to scan the sample.
Figure A.1 Plot showing error associated with XRFS reading against time taken on
scan
The plot shows the inverse exponential relationship between time and error. This indicates
that after the first minute of scanning, the benefit decreases exponentially with the period of
scanning time. It was subsequently found that 30 seconds was the optimum length of time to
scan samples for optimum balance between getting accurate measurements for single
samples, and scanning as many samples as possible.
A1.2 Sample variability
The variability within a single piece of moulded plastic was investigated. From 16 readings it
was found that variability within a single piece was very low, with a relative standard deviation
y = -2.124ln(x) + 12.689 R² = 0.9189
0
2
4
6
8
10
12
0 20 40 60 80 100 120 140
Time versus error
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of 8.4%. Much of this observed variability can be attributed to the average error on these
readings of 6.9%. It was therefore considered that the variability within a single piece of
plastic was insignificant.
A2 Method for GCMS
High resolution GCMS analysis was carried out by two laboratories, Marchwood Scientific
Services (MSS) and the Fraunhoffer Institute in Germany. The Fraunhoffer Institute were
contracted to provide confirmatory data on four samples following the development of a new
method by MSS. A mixed sub-sample of the laboratory test sample prepared by MSS was
tested by the Fraunhoffer Institute. The congener suites used by the two test laboratories
differed slightly but provided good overlap.
The methods adopted by these two laboratories are summarised in the following sections.
A2.1 Fraunhoffer Institute
Applied methods were in accordance with IEC 62321. The Fraunhoffer laboratory considered
that UK sample preparation was acceptable, both in terms of avoiding excessive heating
(which would be indicated by the smell of degraded polymers) and from the quality of the
measured PBDE fingerprints. Materials were extracted /dissolved with tetrahydrofurane and
extracts solutions were first purified by precipitation with hexane. Precipitated polymers were
re-extracted and precipitated twice with the resulting extracts combined. The combined
extract was reduced to 1 ml by vacuum rotary evaporation and then purified on a 500 mg
Silica SPE (Strata Si -1, Phenomonex). SPE was preconditioned with hexane and PBDEs
were eluted with hexane.
Cleaned extracts were again reduced to 0.5 to 1 ml by a gentle stream of nitrogen. A 10 μl
aliquot of the extract was combined with 10 μl of an internal standard mixture (BFR-LCS,
Wellington) and subjected to GCMS (Shimadzu 2010). The GCMS was operated in SIM
monitoring to fragment ions per analyte. Recovery data for the stated clean-up procedures
and matrix spiked samples met internal quality control requirements.
A2.2 Marchwood Scientific Services
The majority of analysis for PBDEs that has been undertaken worldwide is on environmental
samples, typically for water, soil, sediment and aquatic mammals. MSS has successfully
analysed a large number of this type of sample previously using established methods using
High Resolution Gas Chromatography-Mass Spectrometry. MSS undertook an intensive
period of method development to undertake the analysis of PBDEs in commercial plastic
samples. C13 labelled standards were sourced to assist in method validation.
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The first step involved defining a sample preparation protocol to produce a <1 mm particle
size fine ground laboratory sample for extraction of PBDEs. A Retsch grinder (a ZM1 ultra-
centrifugal mill) was purchased to prepare a <1 mm ground sample for testing. This
equipment avoids the production of undue heat which both melts the plastic and leads to
degradation of the PBDEs). Prepared samples were stored in dark bottles to limit
photodegradation. A 0.1 gram representative sub sample of the ground material was then
taken for analysis. The 0.1 gram portion was placed in a soxhlet thimble and inserted into a
soxhlet extraction apparatus. A toluene solvent extraction was then undertaken for
approximately 12 hours. At the end of the extraction period the solvent phase was cooled and
subjected to vacuum rotary evaporation to reduce the solvent volume to 1 ml. The sample
was then purified on a 500 mg Silica SPE column and any PBDEs present in the sample were
eluted with hexane. An aliquot of the clean extract was then analysed by High Resolution Gas
Chromatography-Mass Spectrometry (Waters Micromass). Considerable work was
undertaken to optimise the preparation, extraction and analytical methods and get acceptable
recovery of labelled C13 compounds in all stages. Final concentrations of PBDEs were
calculated based on the original weight of sample presented for extraction. The analytical
methodology used to undertake analysis of plastic samples by MSS has been optimised for
the determination of PBDEs in plastic materials. Additionally the use of labelled internal
standards allows concentration of PBDEs to be determined using internal standardisation
which allows recovery correction of PBDE data. The use of internal standards eliminates the
need for correction equations (or recovery factors). This approach to analysis is established
and applied in a wide range of analytical applications.
The method developed by MSS for the determination of PBDEs in plastics requires the
assessment of PBDE recovery from a matrix sample to provide full method validation (a
‘blank’ or low PBDE plastic reference sample could not be obtained within the timeframe of
the method development activities, but this will be addressed if further testing is required).
Criteria for acceptance of calibration samples (including a standard reference material) and
internals standard recovery have been agreed for future testing.
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Appendix B Results
B1 Samples selected for GCMS analysis and tests data
Table B.1 Samples submitted for GCMS analysis and XRFS screening data
Category Sample code No. Samples Average Br content
of the bag by XRFS
(mg/kg) Small WEEE A3 1¹ 400 Coat hangers A11 4 1000 TVs A14 4 6000 Computer monitors A26, A28, A33 7 10000 Fridges A6 2 450 Digiboxes A9 4 1200 Industrial IT equipment F1 1 20000 Mixed IT waste and
telephones F2 4 20000
Printed circuit boards S10, S19b 2 25000* Granulated plastic
output A41 1 40000
Small WEEE A3 1 400
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Table B.2 MSS GCMS PBDE test data
Component description Concentration (mg/kg)
XRFS tri tetra penta hexa hepta octa nona deca Sample code
Cloth from car headrest - 0.0032 0.025 0.031 0.058 0.35 - - 20 C16
Coat hangers <LOD 0.0025 0.029 0.056 0.14 0.72 0.073 0.11 21 A11
Coat hangers – high High 0.76 3.5 5.6 75 3400 640 290 80000 A11
Coat hangers – low Low 0.0031 0.039 0.075 1.3 7.7 0.97 2 93 A11
Coat hangers – medium Medium 0.055 0.3 0.74 2.3 7.2 - 18 2800 A11
cordless telephone - 0.0014 0.032 0.064 0.2 1 0.046 1.5 790 C11
Digiboxes (high impact plastic - HIPs) Low 0.0002 0.0029 0.0039 0.0091 0.039 - - 4.4 A8
Digiboxes (high impact plastic - HIPs) Medium 0.27 - 0.0035 0.33 2.8 - 0.27 520 A8
Digiboxes (high impact plastic - HIPs) High 2.3 220 460 1500 5000 1700 290 5700 A8
Digiboxes (high impact plastic - HIPs) - 0.0015 0.026 0.049 0.16 0.83 0.042 1.4 290 A8
Dishwasher switch cover - 0.043 0.096 0.53 2.8 3.3 1.2 180 2000 C9
dishwasher timer - 0.00095 0.036 0.08 0.28 1.5 - 5.2 910 C10
Facia washing machine - 0.0035 0.029 0.042 0.14 0.95 0.036 0.13 1300 C5
Fridges Fines 0.32 0.51 1.6 13 44 4.2 28 160 A6
Fridges >1mm 0.5 3.2 4.5 11 - 6.4 12 79 A6
Industrial IT waste High 25 250 430 1200 6000 - 620 32000 F3
Industrial IT waste Medium 0.12 3.3 6.7 15 95 48 37 12000 F3
Industrial IT waste Low 0.0029 0.0084 0.019 0.14 0.41 0.052 0.011 2.9 F3
Industrial IT waste <LOD 0.019 0.00022 0.00038 0.00097 0.0047 - 0.04 0.16 F3
Industrial IT waste - 0.44 3.1 3.6 10 55 - 960 50000 F3
Microwave door - 0.0005 0.0071 0.047 0.2 0.18 - 3.6 2500 C6
PC cover - 2.1 6.9 9.9 24 110 - - 5800 C13
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Component description Concentration (mg/kg)
XRFS tri tetra penta hexa hepta octa nona deca Sample code
PC monitors High 0.08 0.17 0.21 3.1 20 1.8 490 14000 A17
PC monitors Medium 0.021 0.56 1 2.4 14 - 26 2400 A17
PC monitors Low 0.011 0.13 0.27 0.82 4.7 0.65 0.16 6.1 A17
PC monitors - 0.031 0.41 0.85 2.6 14 2.8 16 8000 A26
Printed circuit board cover - wash machine - 0.55 3 7.4 23 72 - 180 28000 C3
Printed circuit boards High 2.4 11 15 580 5200 170 640 130000 S10
Printed circuit boards High 1.3 5.9 7 310 2800 - 270 42000 S19b
Processed dense fraction - 0.16 2.2 4.2 340 930 12 4 2400 A41
Processed plastic - 0.14 1.8 4.5 290 840 10 3.5 2600 A31
Razor - 0.0056 0.035 0.062 3.8 21 3.3 0.61 40 C12
Small WEEE - 0.37 3.3 5.1 8 41 5.4 5.5 780 A3
Transformer cover - 6.5 14 65 310 450 180 790 23000 C1
TVs - 2.3 13 16 640 5200 63 15 140000 A39.1
TVs - 1.7 6.6 8.5 310 2800 360 85 44000 A39.2
TVs Medium 3.2 5.1 16 130 440 42 280 1600 A39.3
TVs - 0.028 0.42 0.94 2.9 17 3.2 13 11000 A13
TVs - 0.28 4.1 7.6 19 110 8.6 130 98000 C4
TVs - 5.2 30 56 4800 23000 4300 720 51000 C8
TVs Low - 0.0049 0.011 0.026 0.12 - - 21 A28
TVs high 21 2100 4400 14000 36000 1900 900 53000 A28
TVs <LOD - 0.16 0.32 0.96 5.5 0.71 0.07 34 A28
Washing machine door catch - 1.8 7.1 6.6 310 3800 430 88 46000 C14
Washing machine door - 1.5 7.4 30 47 250 - - 18000 C7
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Table B.3 Detailed breakdown of MSS GCMS analysis data
Sample type Average RSD Count Mass % >10000 mg/kg Sample code
Coat hangers 1105 3.5 50 67.8 2 A11
Digiboxes 11007 2.9 50 134 20 A8
Fridges 305 4.1 20 1061 0 A1
PC monitor 9769 2.8 66 605.3 15 A33
PC monitor 15591 2.2 50 534.5 14 A17
PC monitor 608 1.4 20 1068 0 A15
PC monitor 6962 3.4 36 221.3 8.3 A33
PC monitor 7943 3.2 36 246.3 8.3 A33
Printed circuit boards 41888 0.7 30 198.7 83 S16
Printed circuit boards 47675 0.6 30 235 86 S10
Printed circuit boards 43045 0.5 30 332 90 S19b
Small WEEE 790 2.3 20 1068 0 A3
Telephones 39999 1.1 51 290.5 39 C3
TVs 16754 2.2 65 271.1 15 A14
TVs 12299 2.5 54 260.5 18 A28
TVs 10782 3.4 49 257.34 8 A39
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B2 Statistical data review (to support range estimates)
Figures B.1 and B.2 summarise the hepta-BDE GCMS results as histograms, and suggest
that the PBDE concentrations can be regarded as log-normally distributed.
Figure B.1 Histogram of hepta-BDE concentrations in all WEEE categories,
excluding TVs
Figure B.2 Histogram of hepta-BDE concentrations in sampled TVs
The concentrations of PBDEs of different groups are also highly correlated (Table B.4 and
Figure B.3) as would be expected from widespread use of a limited number of commercial
formulations.
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Table B.4 Correlation in GCMS data between hepta- and deca-BDE
log10 concentrations Tetra Penta Hexa Hepta Deca
Correlation coefficients
with hepta 0.93 0.91 0.99 - 0.80
Mean -0.21 0.05 0.86 1.54 3.21
Figure B.3 Scatter graph hepta and deca PBDE concentrations (all ‘whole’ samples
& sub-samples)
0.001
0.01
0.1
1
10
100
1000
10000
100000
0.1 1 10 100 1000 10000 1000001000000Hep
ta c
on
cen
trati
on
m
g/k
g
Deca concentration mg/kg
B3 Estimates of PBDE concentration ranges in UK WEEE
Concentration ranges have been estimated for PBDE in UK WEEE by congener group (Table
4.2) and for Stockholm listed PBDEs (Table 4.3) for UK WEEE using the results in Table B.2
and assuming that the data is log-normally distributed. For TVs the ranges are wider than the
observed minima and maxima, because of the small number of samples. The overall
estimates would be substantially improved if the number of samples in each category was
increased by further sampling and testing, ideally to make the total number of samples in
each category up to 12. This would allow the corresponding distributions of PBDE
concentrations to be estimated: i.e. confirmation of log-normality, and calculation of summary
statistics including the mean, variance and upper and lower percentiles. There is some scope
for reducing the sample numbers down to a minimum of say 8 for each component waste
stream, at the cost of greater uncertainty in the estimates. Further examination of the test data
to further determine the correlations between congener concentrations, and between the
GCMS and XRFS results could be used to gain the maximum information from sampling and
analysis at minimum cost. High correlations imply scope for analysing the samples for a small
number of parameters and estimating the values of other parameters. The range data
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illustrates that the 'within sample' variability is substantial and care must therefore be taken to
collect representative samples for testing that contain pieces from a large number of units.
Confidence limits have been estimated for the PBDE range data. The confidence limits
assume that samples have been chosen randomly. Published data for UK waste arisings
(Table 1.1) and the weight of brominated plastics in consumer items (Table 1.2) are assumed
to be correct. Estimated range data and confidence limits are provided in Table B.5.
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Table B.5 Estimated confidence limits for range estimates of PBDEs in UK waste stream
Waste category
UK waste (2010) Brominated
plastics in waste
No. of
samples Mean PBDE concentrations in samples (mg/kg) Weight in UK waste (tonnes)
Tonnes % by
weight % Tonnes Tetra Penta Hexa Hepta
All
Stockholm
listed
Best
estimate
Lower
limit
(5%ile)
Upper
limit
(95%ile)
Large household
appliances 141,236 31.0% 0.29% 410 6 2.9 7.4 63.9 688.0 762.2 0.312 0.067 0.817
Cooling appliances
containing
refridgerants 97,414 21.0% 0.29% 283 2 1.9 3.1 6.5 25.2 36.6 0.010 0.003 0.022
Small household
appliances 22,870 5.0% 0.75% 172 3 1.1 1.7 2.8 14.1 19.7 0.003 0.001 0.009
ICT & consumer
electronics 186,435 40.0% 18.00% 33,558 15 26 51 582 3002 3661 123 53 242
Lamps 0.4 0.0%
Other waste 13,265 3.0%
Total (tonnes/year) 461,220
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B4 Interlaboratory comparison of GCMS data
Direct comparison between the MSS and Fraunhofer results is possible for 5 samples (Table
B.6) and 14 PBDE congeners. To illustrate the similarities and differences between the two
sets of laboratory results, MSS concentrations reported as being less than 50 ppb (or
recorded as ‘-‘) were replaced with half the Fraunhofer limit of detection, i.e. 25 ppb. Similarly
Fraunhofer results of ‘<50’ were replaced with 25 ppb (Table B.7).
Logs to base 10 were calculated for all the results, and the differences between the log values
(MSS – Fraunhofer) were calculated. Thus a difference of 1.0 would show that the MSS result
was a factor of 10 greater than the Fraunhofer result; these are shown in bold type in Table
B.8. A zero difference occurs when the results from both laboratories were below the
detection limit; these are shown in italic type in Table B.8. A number of conclusions can be
drawn from the data:
MSS results for sample S10 High are much higher than Fraunhofer’s.
MSS results are higher than Fraunhofer’s for 3 congeners: 183, 154 and 100.
If these 3 congeners and the S10 ‘High sample’ are excluded, there is a fair measure of
agreement between the laboratories (Table B.9). As the data comparison between
other samples is acceptable, the poor correlation in data in Sample S10 high may be
explained by sample heterogeneity, XRFS showed that the individual pieces of plastic
in this sample had widely differing concentrations of PBDEs, this may impact on the
homogeneity of the sample even when it is finely ground.
Table B.6 Samples tested for interlaboratory comparison
Sample Description
A17 High TV casings
A41 Dense (high Br) fraction from reprocessor
C10 Washing machine door
C11 Circuit board casing (washing machine)
S10 High Printed circuit boards, mixed
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Table B.7 Summary of MSS and Fraunhofer PBDE results
Congener 17 28 47 66 71 85 99 100 138 153 154 183 203 209 Total tetra
- hepta tri tri tetra tetra tetra penta penta penta hexa hexa hexa hepta octa deca
Fraunhofer
A17 High 25 25 25 25 99 25 25 25 154 320 25 578 173 13,557,000 1,301
A41 25 25 1,180 25 25 25 1,532 25 275 8,045 612 69,222 9,524 746,000 80,966
C10 25 25 25 25 25 25 25 25 25 20 25 25 25 178,000 245
C11 25 25 25 25 25 25 25 25 242 25 25 88 81 1,157,000 530
S10 High 25 25 25 25 25 189 25 25 25 25 25 25 25 676,000 414
MSS
A17 High 25 69 139 25 25 25 25 184 25 418 2,588 19,013 1,815 13,921,404 22,466
A41 25 140 2,202 25 25 101 616 3,519 344 36,306 302,450 929,570 12,201 2,354,575 1,275,157
C10 25 25 25 25 25 25 25 66 25 25 235 1,496 25 911,818 1,972
C11 25 25 25 25 25 25 25 55 25 25 179 1,042 25 791,748 1,451
S10 High 1,393 1,017 9,639 1,272 318 25 1,637 13,450 25 42,101 540,261 5,231,142 172,978 129,045,077 5,839,870
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Table B.8 Comparison of MSS and Fraunhofer PBDE results
Sample
Congener Total tetra
- hepta 17 28 47 66 71 85 99 100 138 153 154 183 203 209
tri tri tetra tetra tetra penta penta penta Hexa hexa hexa hepta octa deca
A17 High 0.0 0.4 0.7 0.0 -0.6 0.0 0.0 0.9 -0.8 0.1 2.0 1.5 1.0 0.0 1.2
A41 0.0 0.7 0.3 0.0 0.0 0.6 -0.4 2.1 0.1 0.7 2.7 1.1 0.1 0.5 1.2
C10 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.4 0.0 0.1 1.0 1.8 0.0 0.7 0.9
C11 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.3 -1.0 0.0 0.9 1.1 -0.5 -0.2 0.4
S10 High 1.7 1.6 2.6 1.7 1.1 -0.9 1.8 2.7 0.0 3.2 4.3 5.3 3.8 2.3 4.1
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Table B.9 Summary of interlaboratory GCMS data comparison
Log10(M/F) <-0.5 -0.5 to +0.5 >+0.5 Total
Sample S10 High 5 37 (25) 28 70
Congeners 100, 154 & 183 4 36 (24) 16 56
4 samples * 11 congeners 4 34 (24) 6 44
Note 1: the numbers in brackets in the middle column show the sample – congener combinations for
which both laboratories’ results were below the detection limit
Note 2: log10(M/F) is the log to base 10 of the MSS to Fraunhofer ratio. A value of 0.5 corresponds
roughly to a factor of 3 difference.