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Inventory Review Report 2012

Annex F - Review of POP Emission Inventories

AEA Technology plc, United Kingdom

Robert Whiting (ETC-ACM)

CONTENT

1 Introduction................................................................................................................................... 2

1.1 Methodology .......................................................................................................................... 2

1.1.1 Developing source profiles ............................................................................................. 3

2 Results and discussion ............................................................................................................. 5

2.1 Review of completeness and consistency ........................................................................ 5

2.2 Review of emission factor variability ............................................................................... 7

2.2.1 Review of emission factors for PCDD/F in Iron and Steel ......................................... 7

2.2.2 Review of emission factors for PAHs in domestic fuel use ..................................... 11

3 Summary .................................................................................................................................. 13

4 Recommendations .................................................................................................................. 14

5 Appendix:................................................................................................................................. 15

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1 Introduction

POPs (Persistent Organic Pollutants) are a set of pollutants which have caused considerable

international concern over potential effects to the environment and human health. This is due to their

persistent nature in the environment, capability to bioaccumulate up food-chains and perceived health

effects, with a number of them being recognised as carcinogens. Their persistent nature also makes

the likelihood of long range transport a possibility.

The UNECE Convention on Long-Range Transboundary Air Pollution (CLR-TAP) provides

intervention under the 1998 Aarhus protocol on POPs. The protocol puts in place a set of defined

criteria for identifying POPs and annexes (numbered I, II and III) to manage substances banned from

sale, restricted or unintentionally released respectively. This latter annex (annex III) places reporting

requirements on the ratified nations to provide emission inventories annually for the unintentionally

released POPs covered under annex III (dioxins and furans, polychlorinated biphenyls,

hexachlorobenzene and poly aromatic hydrocarbons (limited to 4 specific congeners)).

The emission inventories for POPs submitted under CLR-TAP provide vital context to emission

trends and identification of key sources. This element is vital to meeting the overall requirements of

the protocol, which require emission reductions for POPs released to air. Therefore the completeness

and consistency of different national inventories when compared at international level is of key

concern to ensure that the data provided is of the best quality possible.

The current review commissioned by the European Environment Agency provides analysis of the data

submitted under CLR-TAP. The specific objectives of the review were to assess the POPs inventories

developed by reporting nations for completeness, overall consistency across all reporting nations and

a deeper assessment to provide better understanding of any issues surrounding data gaps or use of

emission factors which would affect overall totals.

1.1 Methodology

The derivation of emission estimates for POPs is complicated by a number of factors. Dioxins and

furans, PCBs (polychlorinated biphenyls) and PAHs (poly aromatic hydrocarbons) are families of

chemicals rather than a single substance, and the environmental impacts of individual members of

each family differ in magnitude. For this reason, emission estimates for dioxins and furans make use

of Toxic Equivalent Factors (called TEQs) in order to present comparable emissions data for different

sources. This adds to the complexity and cost of researching emission factors, for example through

source testing, and leads to a scarcity of new data. There is a danger of emission factors that are

reported in the literature being recycled and reproduced continually with the potential for loss of

context and misinterpretation of the data in subsequent uses. In worst cases, errors can be introduced

into data, further diluting the usefulness of the already limited data set. A further complication for

PAHs in particular is the use of different conventions for the reporting of emission factors, with use

made of aggregate emission factors covering variously 4, 6, 8, or 16 congeners.

To assist in the compilation of POPs emission inventories, EMEP (European Monitoring and

Evaluation Programme) provides an inventory guidebook. The Stockholm Convention also makes

available a dioxins and furans ‘toolkit’ with guidance on the use of factors, and identification of

sources to help in inventory development. These resources are intended to provide guidance to the

inventory compiler in identifying the relevant emission sources for their nation and to assist in

producing estimates across a time-series of years beginning with an emission year of 1990.

The current review assessed existing inventories on a number of issues:

How complete are the inventories?

Where incomplete, what are the key gaps in terms of emission sources?

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How consistent are emission estimates across all nations?

What impact does emission factor variability have on estimates and, thereby, on consistency across

national reporting?

The review carried out has adopted a ‘back to basics’ approach to review the inventories submitted

under CLR-TAP for the 2010 emission year. The methodology involved two principle steps.

i) Review for completeness and consistency of inventories

This stage began with a review of existing core reference materials to build up source profiles for each

POP (PAHs as sum of 4 congeners). These source profiles were then used to evaluate the inventories

submitted under CLR-TAP, assessing the likelihood of gaps in those inventories, and therefore

providing an initial review of completeness for each individual inventory.

As well using the source profiles to assess the consistency of inventories a series of manual checks

were made based on expert judgement to look for source gaps and overall integrity of all inventories

compared alongside one another. Using the source profiles as a guide, inventories at the national level

were checked for the number of sources per POP and in particular where any one source accounted

for more than 50% of the total emission for that POP from a given inventory. It should be noted that

in some cases it is possible for a single source to dominate to this extent, and therefore due care is

needed to assess each inventory, using in part the other inventories as a guide of likely correctness.

ii) Review of emission factor variability

The second stage of the review looked to assess the impact of variability in emission factors for key

sources. Based on the results of the first stage and expert knowledge, two key of the most significant

source categories (dioxins and furans from iron and steel, and PAHs from domestic combustion of

fuels) were selected. The sources selected were found in the majority of national inventories.

Statistical activity data was then used to take the reported emissions and derive emission factors. This

process was carried out using standard emission inventory compilation guidelines as per EMEP. The

resulting factors were then reviewed for variation and comparison to guidebook factors. As variation

within emission factors for significant sources has a knock on effect for overall emission estimates the

impact of emission factor variation on total emission was also considered in this process.

1.1.1 Developing source profiles

The first process within stage i of the review was to develop of new source profiles for each POP in

turn based on the NFR classification scheme for emission sources. The reasoning behind developing

new source profiles was that there are significant differences in the source lists given by different

reference sources. The source profiles that were derived document which of the reference materials

provide support for the inclusion of each emission source through use of a numbering scheme:

1) Stockholm Convention – dioxins and furans toolkit

2) EMEP guidebook

3) Joint Research Centre – BREF Notes

4) UK POPs inventory

5) European Pollutant Release and Transfer Register (E-PRTR)

6) TNO POPs database.

Figure 1 shows the source profile for PCBs and the full source profiles are also detailed in appendix I

of this document. Once the source profiles had been completed they were further disaggregated into

two pools:

- generic sources, which all nations should have.

- non-generic sources, which may only apply to specific nations.

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The source profiles were also given an indicative assessment for likely key sources based on personal

experience. The generic sources in figure 1 are highlighted in green with key generic sources in light

green. NFR 2F – use of PCB in di-electric equipment has also been highlighted (in yellow) as a key

source. While use of PCBs in di-electric was widespread it is unclear whether it would occur for all

nations and so has been marked as non-generic.

Figure 1 – Source Profile for PCBs

*Generic sources in Green, with key generic sources in light green. NFR 2F highlighted in yellow as a

key non-generic source.

NFR Category Description Reference Generic Major Source

1A1a Power Plants - fossil fuels 2,4,5,6 Y -

1A1a

Energy from Waste (formerly Incineration -

Municipal Waste) 2,3,4,5,6 Y Y

1A2fi

Industrial/manufacturing Combustion of

Fossil Fuels 2,4,6 Y -

1A4bi Domestic Combustion - Solid fuels 2,4,6 Y -

1A4ci Agricultural combustion of fossil fuels 2,4 Y -

6A Landfills - emissions to air 4 Y -

6A Sewage Sludge spreading to land 4 Y Y

6Ce Backyard burning and bonfires 4 Y Y

6D Accidental vehicle fires 4 Y Y

7A Accidental building fires 4 Y Y

z_11C Accidental forest and vegetation fires 4 Y -

1A1b Petroleum Refinery - Fuel Combustion 6 - -

1A1c Manufacture of solid smokeless fuel 4 - -

1A1c Town Gas 4 - -

1A1c Coal Mining - Coal combustion 4,5 - -

1A2a Iron and Steel - fuel use 2,4 Y

1A2fi Cement Manufacture - waste fuels 2,3,4,5 - -

1A2fi Lime Manufacture - Fuels 4 - -

1A3dii Coastal Navigation 2,4 -

1B1b Manufacture of solid smokeless fuel 6 - -

2A7d Glass Manufacture 5 - -

2C1 Coke Production 2,3,4 - -

2C1 Iron and Steel - Sintering 2,3,4,5,6 - -

2C1 Iron and Steel - EAF 2,4 - -

2C1 Iron and Steel - Blast Furnace 2,4 - -

2C1 Iron and Steel - Basic Oxygen Furnace 2,4,6 - Y

2C1 Pig Iron 2,5 - -

2C5a Secondary Copper Production 2 - -

2C5b Secondary Lead Production 2 - -

2C5d Secondary Zinc Production 2 - -

2D1

Paper and Pulp Manufacture (Chlorine

processed - Kraft) 3 - -

2F

Di-electric Equipment - Transformers and

capacitors 2,4 * Y

3C organic chemical manufacture 3 - Y

4F Agricultural field burning 4 - -

6Ca Incineration - Clinical Waste 2,4,6 - Y

6Cb Incineration - Hazardous Waste 3,4,5,6 - Y

6Cb Incineration - Sewage Sludge 4 - -

6Ce Agricultural Waste burning 4 - -

6D Manufacture of Refuse Derived Fuel 4 - -

z_1A3di(i) International Navigation - Fuel Oil 2 - -

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2 Results and discussion

The results and discussion of the review are given in this section under the headings of the two steps

carried out in the methodology.

2.1 Review of completeness and consistency

The results of the review for completeness and consistency provide some very clear messages. This

section is intended to provide a summary of the key details; tables providing the comparison of source

profiles to inventories submitted under CLR-TAP are provided in appendix II at the end of this report.

The initial review of the emission estimates submitted to CLR-TAP revealed different numbers of

inventories submitted for different POPs. The total numbers are shown in table 1 but highlight that 25

inventories for PCB were submitted compared to 35 for PAHs. Please note one additional national

inventory (including dioxins and furans, HCB and PAH) was submitted after the review timeframe

and has not been included in the findings of the data analysed.

Table 1 – number of POPs inventories submitted for review

Persistent Organic Pollutant Number of national inventories submitted to

CLR-TAP 2010 (emission year)

Dioxins and Furans 34

Polychlorinated Biphenyls 25

Hexachlorobenzene 28

Poly Aromatic Hydrocarbons 35

The source profiles developed for this phase were used to analyse the inventories submitted, based on

the ‘generic pool’ of sources only. This takes into account that it was not possible to state for the non-

generic pool whether a given country should genuinely have a source at a given NFR classification.

The review using source profiles was intended to highlight source gaps and general completeness; it

was not possible to use this method alone to comment on the variance in quantity of emissions for any

given source between different reporting nations.

The results of the review highlight a high level of response for sources where the required ‘activity’

and ‘emission / emission factor’ data are likely to be readily available. For example PAH emissions

associated with NFR 1A1a – combustion of fuels in public power generation shows 91% of the

reported inventories have a source under this classification. A similar result is found for other POPs

with another example being NFR 1A2fi – combustion of fuels for power in industry, where 94% of

the reported inventories contain a source for dioxins and furans.

For the NFR sources where the required ‘activity’ data is scarce or difficult to calculate the reverse is

true, for example under NFR 6Ce – domestic combustion of wastes, only 32% of inventories have a

source for dioxins and furans, and only 26% for PAHs. This potentially represents a significant gap

within the POPs emission inventories. Regulation of industrial sources of POPs, particularly

incineration has resulted in a significant decline in emissions from these sources; however this in turn

will increase the importance of emissions from diffuse sources such as domestic waste burning and

accidental fires.

The total dioxins and furans emissions for NFR 6Ce reported for all inventories in the 2010 emission

year was 116 g I-TEQ compared to NFR 1A1a (97 g I-TEQ) and NFR 1A2fi (129 g I-TEQ). This

shows broadly comparable levels of emission across all three sources, however it should be noted that

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only 32% of the reported inventories calculated estimates for NFR 6Ce compared >90% for NFR

1A1a and 1A2fi.

One further area of concern was highlighted by the source profile review. As stated the review was

based solely on the ‘generic pool’ of sources with one exception. The use of PCBs within di-electric

equipment as a heat transfer fluid was wide-spread and would likely appear in most countries,

however it was not possible to confirm whether this would be the case for all, hence it was added to

the non-generic pool. During the review of the submitted inventories NFR 2F for PCB was also

reviewed this showed that only 4 out of the 25 inventories contained a source for this entry. One other

nation included the PCB di-electric emissions under NFR 2G.

PCBs were widely used in transformers and capacitors as heat transfer fluid. Open use of PCBs was

banned within Europe in the 1970s but continued to be used in di-electric equipment until a full ban

was introduced in 1985 under Directive 85/467/EEC. Given their wide-spread use, this ban was

limited to ‘new’ equipment with existing stock allowed to remain in place with suitable requirements

drafted for waste and end of life issues. This has meant that the PCB stockpiles within di-electric

equipment have produced a legacy issue, with the key emission route through leaking older

equipment.

The life-span of such equipment is difficult to gauge but industrial based goods are expected to have a

typical life-span of 20 years, with potential life-span of up to 40 years. This reflects the fact that the

items form part of electrical networks that can face logistical issues for replacement and upgrade. This

issue is further complicated where equipment is ‘re-filled’ with new fluids without properly

decontaminating the item first, meaning the new fill becomes contaminated with a smaller dose of

PCB.

PCBs from di-electric equipment still represent the key source for emission inventories. The total

PCB emission from all inventories for NFR 2F is 1.6 tonnes (based on 4 inventories of 25), the next

most significant source is NFR 6Cb – Industrial waste incineration which is 1 tonne. However it

should also be noted that the uncertainty in estimates for NFR 2F will be high.

Alongside the source profile review of inventories a manual check was also carried out. This was

intended to look at composition of each inventory for the number of sources and also quantity of

emission between different sources in the same inventory. Table 2 provides the results of these

manual checks, again with a clear set of messages.

The manual checks observed whether particular source categories dominated emission inventories,

and also looked to see where inventories had very few sources (assumed to be 3 or less). Based on the

source profiles developed the majority of the annex III POPs are linked to fuel combustion so for the

‘generic pool’ theses should include as a minimum the following five: 1A1a – Public power

generation, 1A2fi – power generation in industry, 1A4ai – power and heat for institutional and public

buildings, 1A4bi – domestic combustion of fuels, and 1A4ci – agricultural combustion of fuels, this

sits outside of the emissions which will be associated with metal manufacture and incineration.

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Table 2 – table of completeness for sources

Persistent Organic

Pollutant

Number of countries

with >50% emission

from one source

Number of countries

with three or less

sources

Total number of

inventories submitted

to CLR-TAP

Dioxins and Furans 16 2 34

PCBs 16 4 25

HCB 23 7 28

PAHs 29 2 35

The results from table 2 illustrate that for a number of inventories one source dominates the

emissions, for dioxins and furans and PAHs this was linked to domestic combustion of fuels and

public power generation, and for PCBs this was dominated by iron and steel manufacture. The HCB

inventories reviewed were more variable. From the 28 inventories submitted there were 17 different

main key sources, with the main categories being domestic combustion of fuels and public power (4

inventories each). At the same time 25% of the HCB inventories submitted had three or less sources

with a number reporting all emissions from a single source.

The results shown in table 2 together with the source profile review suggest that a number of sources

are missing from the emission inventories, particularly where activity data is less well documented, or

viable emission factors are more difficult to source. For HCB this is particularly the case with less

clear agreement on what is a defined source, both within the emission inventories submitted, but also

within the EMEP guidebook. The source profile for HCB (see annex I) shows that multiple reference

sources agree on ‘some’ of the recognised NFR categories, particularly with regard to combustion of

fuel for power. However for other sources, particularly some of the non-ferrous metal manufacture

and incineration processes there is less agreement over which should be considered sources and

suitable emission factors.

2.2 Review of emission factor variability

The second stage of the review provided more detail on variation for emission factors within two key

source sectors. The results of the review are intended to provide context on the potential impact that

substantial variation in factors can have on overall emissions. This is of even greater importance

where a specific source category dominates for the overall inventory.

2.2.1 Review of emission factors for PCDD/F in Iron and Steel

Iron and steel production while not a ‘generic’ source is still likely the single most important point

source for the emissions of dioxins and furans, with 27 nations (from 34) reporting emissions for NFR

1A2a+2C1 (combined) in the 2010 year.

In order to derive emission factors based on the reported emissions for iron and steel production,

statistics were taken from the world steel organisation http://www.worldsteel.org/statistics/statistics-

archive/annual-steel-archive.html. One further issue which requires clarification relates to the reported

emissions themselves. For the purpose of deriving emission factors under this review the reported

emissions from NFR 1A2a – fuel use in the iron and steel industries and NFR 2C1 – process

emissions from iron and steel production, were combined. The reporting templates for emission

inventories allow compilers to disaggregate fuel use from process emissions, however in practice

emissions reported under either category could include both combustion and process emissions, for

example, emissions from fuels used in furnaces and any process emissions from those same furnaces

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might well be reported together. Review of the reported emissions (2010 emission year) under 1A2a

and 2C1 for dioxins and furans shows that for 12 nations NFR 2C1 is the key source, for 4 nations

1A2a is the key source and for 8 nations emissions are broadly even. In order to take account of the

possibility of national differences in reporting, we have combined the reported emissions for 1A2a

and 2C1 for the review of iron and steel sector emissions.

Based on the world steel statistics (for 2010) the key iron and steel manufacturing nations covered

under the reporting to CLR-TAP are:

Table 3 – List of major iron and steel producing countries with 2010 steel production.

Germany – 43.8 mt United Kingdom – 9.7 mt

Italy – 25.7 mt Poland – 8.0 mt

Spain – 16.3 mt Belgium – 8.0 mt

France – 15.4 mt Austria – 7.2 mt

Canada – 13.0 mt

Figure 2 illustrates proportionately the dioxin and furan emissions for 2010 from the CLR-TAP

submitted inventories based on the combined NFR 1A2a and 2C1 sources.

Figure 2 – dioxin and furan emissions from CLR-TAP inventories as a proportion of total emission

The results from table 3 and figure 2 show some broad agreement on the emissions vs production for

nations covered under the CLR-TAP reporting, albeit with a couple of notable differences in figure 2

such as the prominent contribution from the Czech Republic. Figure 3 displays the derived emission

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factors based on the data displayed (it was not possible to derive a factor for Ireland due to a lack of

iron and steel production data), with comparison to the guidebook factor given in the box at the top

right hand corner of the graph. The results show a large range in derived emission factors from 0.0019

µg/tonne of steel to 17.7 µg/tonne of steel.

Further discussion on the emission factors is difficult as the NFR 2C1 covers a variety of process

types for the manufacture of iron and steel. Dioxin and furan emissions will be associated with all

process technologies such as basic oxygen furnace, electric arc furnace, as well as sintering and

pelletizing. The NFR 2C1 will also include emissions from grey iron foundries and re-melting

processes for iron and steel.

Broadly the derived emission factors for the major iron and steel producing countries range from 0.75

µg/t to 4.25 µg/t of steel. The results provide some confidence that the variance for what are likely

large integrated steel works is small and the factors in use will have a good level of uncertainty. The

EMEP guidebook factor is 2 µg/t of steel; again within the range of factors for the major iron and

steel producing countries. For the biggest derived emission factor (17.7 µg/t) linked to the Czech

Republic it is worth noting the emission share between 1A2a and 2C1 is broadly even.

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Figure 3 derived emission factors for iron and steel.

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2.2.2 Review of emission factors for PAHs in domestic fuel use

The second key source category to be reviewed was PAH (as the sum of 4 congeners) emissions from

the use of domestic fuels. This particular source category is of high importance: the first review stage

highlighted that in many of the countries where one source of PAH dominated emissions (>50% of

total emission), this was the domestic fuel use sector as shown in table 2.

Fuels are used within the domestic sector primarily for heating, but also for cooking, powering

machinery and smallscale electricity generation. A wide range of appliances are used, such as wood

burning stoves, advanced closed-faced boilers, open fireplaces and hearths, and more traditional

boilers. These appliances will make use of a variety of fuel types including solid fossil fuels such as

coal and anthracite; ’biomass‘ – which covers pre-treated wood pellets and waste wood (both virgin

and treated) as well as green waste; liquid fuels such as gas oil and kerosene, and natural gas and

other gases. Not all fuel types will likely generate emissions of POPs, and so it is important that this is

taken into account when deriving emission factors for the purposes of intra-country comparisons. .

The derived emission factors for the domestic sector have been based on the net calorific values

(NCVs) based on energy budgets for each reporting nation. The energy totals (as TJ) were derived for

solid fuels and biomass only – the fuels that would be expected to cause most emissions of PAH from

domestic combustion, since emissios from liquid and gasesous fuels are thought to be negligible.

Emission factors were then derived using the energy totals and the sum of the reported emissions of 4

PAH congeners (benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene and indeno,(123-

cd),pyrene) for the NFR 1A4bi source category.

Figure 4 displays the derived emission factors for domestic fuel use. It was not possible to derive

acurate factors for Albania, Belarus, Canada, Montenegro, and Serbia as NCVs were not available.

Factors for Switzerland (0.001 kg/TJ) and Ukraine (0.00007 kg/TJ) were very much lower than those

for other countries, and are not included in figure 4, and Georgia, Iceland, Liechtenstein and Portugal

do not report emissions under NFR 1A4bi for PAHs. As with the factors derived for iron & steel

production, there is a broad range in the calculated factors. In this case the values appear to be

grouped broadly into three ranges, with the highest values between 0.74 – 0.54 kg/TJ (11 nations), a

middle group between 0.36 – 0.2 kg/TJ (7 nations) and a group with factors in the range 0.1 – 0.05

kg/TJ (6 nations). As described above, factors for Switzerland and Ukraine were lower still and were

both atypical.

The EMEP guidebook value for sum of PAHs is 0.8 kg/TJ for solid fossil fuels and 0.7 kg/TJ for

biomass. Neither the derived emission factors or the guidebook provides sufficient detail to allow any

assessment of the potential for intra-country differences to be assessed due to differences in appliance

types and/or the age and design of appliances. But it is highly likely that issues such as those will have

a profound impact on PAH emissions and may contribute to differences between the derived emission

factors for different countries. In the absence of detailed information on the influence of appliance

types and other factors on intra-country variations, there is significant uncertainty over whether the

range of emission factors derived reflects real differences in emissions, or merely differences in

inventory methodology. It is worth noting that the group of factors illustrated in figure 4 covering the

range 0.1 – 0.05 kg/TJ are approximately an order of magnitude smaller than the highest factors in

use, which are in the range 0.74 – 0.54 kg/TJ. A worst case scenario might, therefore, assume this

variation in factors was the result of methodological differences only, and therefore that a significant

number of countries were under- or overestimating emissions by upto an order of magnitude.

As stated within the introduction to the report, transparency in the choice of emission factors is

needed in order to help check the consistency and reliability of inventory approach across all nations.

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Figure 4 derived emission factors for the sum of 4 PAH congeners

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3 Summary

The current review has assessed the POPs emission inventories submitted under CLRTAP with

specific objectives to review the overall completeness and consistency in emission estimates across all

nations, and to provide detailed assessment of inventory approach and variation in emission factors

where possible, in order to assess their impact on overall emission estimates.

The review has found:

i) There are varying numbers of inventories submitted to CLR-TAP for the POPs included under

annex III of the POPs protocol, ranging from 25 countries submitting inventories for PCBs to 35

for PAHs. Which suggests that a number of inventories are missing, particularly for PCB and

HCB

ii) Comparison of inventories against the ’generic pool‘ of sources that all nations should have show

that there is a high level of inclusion for sources where activity data and viable emission factors /

emission monitoring are readily available. However, for sources where activity data in particular

are scarce, far fewer inventories include estimates. This potentially represents a key gap in

emission inventories, particularly since regulation is typically reducing emissions from well-

characterized industrial sources, making the absence of estimates for diffuse sources such as

domestic waste burning and accidental fires increasingly important.

iii) One key gap is PCB emissions from NFR 2F – PCB use in dielectric equipment such as

transformers and capacitors. Only 4 out of 25 nations submitting an inventory include estimates

for this source with one further inventory including the estimates under NFR 2G. PCBs within

di-electric equipment represent a legacy issue for POPs but are also likely to be one of the most

significant sources in the majority of countries. This therefore represents a key omission from the

existing inventories.

iv) A significant number of the inventories are dominated by a single source (>50% of total

emission), which will mean the emission factors used and approach for that source will have a

big impact on overall estimates. A single dominant source within a POPs inventory is not

impossible, but in some cases where a single source dominates, it is also true that the inventory

covers only a small number of sources, suggesting that the dominance of one source is at least

partially due to the incompleteness of the emissions data. This is particularly the case for the

HCB inventories where 25% of the reported inventories contain 3 or fewer sources.

v) There is a lack of consistency in the identification of sources and magnitude of sources for HCB

inventories submitted under CLRTAP with 17 different main sources recorded in the 28

inventories submitted. Equally the EMEP guidebook has a lack of viable emission factors for a

number of sources which may lead to further omissions or confusion with national emission

estimates.

vi) More in-depth analysis of emissions data for two key sources has suggested that a broad range of

emission factors is used. Although there are reasons why different countries could need to apply

different emission factors to reflect country-specific issues, it is also possible that methodological

differences are important.. A greater level of transparency and clarity in emission inventories

would be helpful when assessing the consistency and reliability of data sets.

vii) Due to the complexity of the science and the cost of research, the development of new emission

factors is limited. Factors and other emissions data can be repeatedly re-quoted within scientific

literature with a resulting risk of mis-quoting/mis-interpreting the data. Due care is required in

understanding the factors selected for use. This includes values quoted within the EMEP

guidebook.

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4 Recommendations

The current review has highlighted some issues of completeness and consistency within the POPs

emission inventories submitted under CLRTAP. As a follow on from this review it is therefore

possible to make some recommendations for improvement applying a simple ’back to basics’

approach which should assist in improving overall completeness and consistency without undue

effort.

The recommendations listed here are intended to promote communication and discussion between

POPs inventory compilation teams and in particular shared learning between peers.

i) It is strongly recommended that emission estimates are provided for all relevant sources where-

ever possible. The EMEP guidebook provides guidance for tier 1, 2 and 3 approaches where

applicable. A tier 1 emission estimate is better than no estimate at all and is designed to be

relatively easy to derive.

ii) Inventory compilers should check the completeness of their data sets and try to identify sources

that may be missing. One practical method for this would be to review a number of the Informal

Inventory Reports (IIRs) from other nations as a means of benchmarking. However, care is

required when comparing inventories for different countries, and it is recommended that inventory

compilers maintain contact in order to discuss inventory methodologies and emission factors used,

particularly when seeking to generate data to fill perceived gaps in inventories..

iii) For sources where activity data in particular are scarce, it may be necessary for a higher tier

authority such as the TFEIP to work with inventory compilers to help provide guidance and

assistance on a standardized approach to tackle gaps for particular sources such as backyard

burning. Again better co-operation and awareness of what research has been conducted by

different national authorities would help inform this process.

iv) The current review has highlighted the potential for variation in emission factors and has discussed

the potential for literature factors to become cyclic. The recommendation for improving

consistency in this case are three-fold:

a) Firstly there is a need to be transparent and provide as much information as possible regarding

referencing of emission factors when compiling IIRs, and for as much evaluation of the

appropriateness of each emission factor for national conditions as possible (for example, a

statement of whether the emission factor relates to the same or similar technology and

abatement equipment and, if not, how these country-specific factors differ from those for the

emission factor used.

b) Secondly, there is a need for open discussion, reporting, and documentation of emission

factors by the POPs inventory community. Currently, the Finnish inventory team at SYKE

provide a reference library source which should be maintained and improved by inventory

compilers providing current data.

c) Measures are needed to improve awareness of new research projects, and dissemination of

results, especially given the relatively infrequent nature of new research, and, therefore, the

value of new data. We would encourage inventory compilers to assist each other by providing

details of on-going research and to publicize results as widely as possible.

Annex F

15 /22

5 Appendix:

i) Source Profiles for POPs

ii) Results of comparison of source profiles

Annex F

16 /22

I Source Profiles for POPs

Reference codes for dioxins and furans, PCBs and PAHs.

Number Source

1 Stockholm Convention Tool-Kit

2 EMEP Guide-Book

3 EU Joint Research Centre ‘BREF’ Notes

4 UK Inventory POPs inventory

5 European-Pollutant Release and Transfer Register

6 TNO POPs database

Reference codes for HCB

Number Source

1 Stockholm Convention Tool-Kit

2 EMEP Guide-Book

3 EU Joint Research Centre ‘BREF’ Notes

4 UK Inventory POPs inventory

5 European-Pollutant Release and Transfer Register

6 Bailey, R.E. 2001. Global hexachlorobenzene

emission. Chemosphere 43, 167-182.

7 TNO POPs Database

*Generic sources in Green, with key generic sources in light green. NFR 2F for PCB highlighted in

yellow as a key non-generic source.

Annex F

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Dioxins and Furans

Annex F

18 /22

PCBs

NFR Category Description Reference Generic Major Source

1A1a Power Plants - fossil fuels 2,4,5,6 Y -

1A1a

Energy from Waste (formerly Incineration -

Municipal Waste) 2,3,4,5,6 Y Y

1A2fi

Industrial/manufacturing Combustion of

Fossil Fuels 2,4,6 Y -

1A4bi Domestic Combustion - Solid fuels 2,4,6 Y -

1A4ci Agricultural combustion of fossil fuels 2,4 Y -

6A Landfills - emissions to air 4 Y -

6A Sewage Sludge spreading to land 4 Y Y

6Ce Backyard burning and bonfires 4 Y Y

6D Accidental vehicle fires 4 Y Y

7A Accidental building fires 4 Y Y

z_11C Accidental forest and vegetation fires 4 Y -

1A1b Petroleum Refinery - Fuel Combustion 6 - -

1A1c Manufacture of solid smokeless fuel 4 - -

1A1c Town Gas 4 - -

1A1c Coal Mining - Coal combustion 4,5 - -

1A2a Iron and Steel - fuel use 2,4 Y

1A2fi Cement Manufacture - waste fuels 2,3,4,5 - -

1A2fi Lime Manufacture - Fuels 4 - -

1A3dii Coastal Navigation 2,4 -

1B1b Manufacture of solid smokeless fuel 6 - -

2A7d Glass Manufacture 5 - -

2C1 Coke Production 2,3,4 - -

2C1 Iron and Steel - Sintering 2,3,4,5,6 - -

2C1 Iron and Steel - EAF 2,4 - -

2C1 Iron and Steel - Blast Furnace 2,4 - -

2C1 Iron and Steel - Basic Oxygen Furnace 2,4,6 - Y

2C1 Pig Iron 2,5 - -

2C5a Secondary Copper Production 2 - -

2C5b Secondary Lead Production 2 - -

2C5d Secondary Zinc Production 2 - -

2D1

Paper and Pulp Manufacture (Chlorine

processed - Kraft) 3 - -

2F

Di-electric Equipment - Transformers and

capacitors 2,4 * Y

3C organic chemical manufacture 3 - Y

4F Agricultural field burning 4 - -

6Ca Incineration - Clinical Waste 2,4,6 - Y

6Cb Incineration - Hazardous Waste 3,4,5,6 - Y

6Cb Incineration - Sewage Sludge 4 - -

6Ce Agricultural Waste burning 4 - -

6D Manufacture of Refuse Derived Fuel 4 - -

z_1A3di(i) International Navigation - Fuel Oil 2 - -

Annex F

19 /22

HCB

* Fireworks have been identified as a potential source of HCB, where HCB is used to make green

colours more vivid. Note the use of HCB within fireworks is illegal in Europe.

NFR Category Description Reference Generic Major Source

1A1a Power stations - fossil fuels 2,6,7 Y Y

1A1a

Energy from Waste (formerly

Incineration - Municipal Waste) 2,4,5,6,7 Y Y

1A4ai

Commercial and Institutional Fuel

use - Coal 2,6,7 Y -

1A4bi Domestic Combustion - Solid fuels 2,6,7 Y Y

1A4ci

Agricultural combustion of fossil

fuels 2,6 Y -

z_11C

Accidental forest and vegetation

fires 6 Y -

1A1a Power Plants - Biomass 2,6 - -

1A2a Iron and Steel - fuel use - coal 2,6,7 - -

1A2fi

Cement Manufacture - waste

fuels 2,4,6 - Y

1A3dii Coastal Navigation 2,4,7 - Y

2C1 Iron and Steel - Sintering 2,3,6,7 - Y

2C3 Secondary Aluminium Production 2,3,6,7 - Y

2C5a Secondary Copper Production 3,6 - Y

2C5c Nickel Production 6 - -

2C5e Magensium Production 6 - -

3C organic chemical manufacture 3,6 - -

3C chlor-alkali plant 3,6 - -

4G Use of pesticidal products 2,4,6 - Y

6Ca Incineration - Clinical Waste 7 - Y

6Cb Incineration - Hazardous Waste 2,4,6,7 - Y

6Cb Incineration - Sewage Sludge 6 -

7A fireworks * -

7A Military smoke grenades 6 - -

z_1A3di(i) International Navigation - Fuel Oil 2,7 - Y

Annex F

20 /22

PAHs

Annex F

21 /22

II Results of comparison of source profiles

Dioxins and furans

PCBs

HCB

Annex F

22 /22

PAHs