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Final version 12 October 2015

Guidance on a semi-field test method for materials that are treated with biocides

to fulfil requirements of the European Biocidal Products Regulation

This guidance document describes a semi-field method for determining the leaching of active

substances or other compounds from materials that contain biocidal products of main group 2

‘Preservatives’ according to the BPR [Regulation (EU) No 528/2012], i.e.

Product-type 7 Film preservatives

Product-type 9 Fibre, leather, rubber and polymerised materials preservatives

Product-type 10 Construction material preservatives

that are intended to be used under outdoor conditions out of ground contact and exposed to rain.

This guidance was developed on the basis of

CEN/TR 16663:2014: Durability of wood and wood-based products - Determination of

emissions from preservative treated wood to the environment - Wooden commodities exposed

in Use Class 3 (Not covered, not in contact with the ground) - Semi-field method

and

NT509 build: NORDTEST Method Leaching of active ingredients from preservative-treated

timber – Semi-field testing

NOTES

The specifications of test conditions, sampling regime and chemical analysis of collected leachates for

the materials considered in this guidance document are the same as in CEN/TR 16663:2014.

Wood preservatives (product-type 8) are not considered in this guidance document since handling of

treated wood is described in CEN/TR 16663:2014.

This guidance applies to materials that are intended for large-area applications. Small-area application

like sealants, or special application techniques require adopted procedures for the preparation of test

specimens. Leachates may be collected and analysed as described in this document.

Treated articles can contain active substances that originate from preservatives for products during

storage (product-type 6).

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Content

1 Description of the test method

2 Terms and Definitions

3 Equipment

4 Test setup

4.1 General

4.2 Sampling of test material

4.3 Preparation of test specimens

4.3.1 Number and size of test specimens

4.3.2 Preparation of test specimens from prefabricated treated articles

4.3.3 Preparation of test specimens from treated articles to be applied to a substrate

4.3.3.1 Substrate

4.3.3.2 Preparation of substrate panels for test specimens

4.3.3.3 Application of test material

4.3.3.4 Conditioning

4.4 Preparation of test setups from test specimens

5 Test procedure

5.1 Exposure test site

5.2 Duration of the test

5.3 Collection of the leachates

5.4 Chemical analysis

6 Results

6.1. Results in concentrations

6.2. Results in terms of emissions

7 Test report

Annex A (informative) Test setup and weathering rack

Annex B (informative) Stability study

Bibliography

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1 Description of the test method

Test setups of test materials are prepared and placed outdoors out of ground contact and exposed to

weathering. The runoff from the test setups is retained and the leachate is monitored by chemical

analyses of the target substances.

Prior to testing customer and appointed laboratory have to clarify which active substances, relevant

transformation products (e.g. metabolites) and other substances of concern according to the BPR

528/2012 (guidance in preparation) and additional physical-chemical parameters have to be analysed

in the leachates.

2 Terms and Definitions

For the purposes of this document, the following terms and definitions apply.

analyte determinant, element, ion or substance to be determined by an

analytical method; synonym for target substance

emission E liberation of chemical substances from a material, into soil, surface

water or groundwater or into the leachant of a test facility

NOTE The emission is expressed in units of released mass per

surface area, i.e. milligrams per square metre.

leachate solution obtained by a field leaching test of a solid product in contact

with rainwater

leaching release of inorganic and/or organic substances from a solid product

by a leachant (in field studies it is rain)

NOTE The leaching is expressed in units of released mass per

surface area, i.e. milligrams per square metre.

prefabricated treated article treated article that is produced and marketed in a way that it can be

used as test specimen without further substrate

test material used synonymously for ‘treated article’ in this document

release synonym for emission

sampling period p period during which a (merged) leachate sample is collected

substrate material used as a base to apply treated articles in order to

produce a test specimen

target substance substances (active substances, transformation products and/or

substances of concern) to be tested

test setup test specimen with installations to be fixed on a weathering rack

test specimen body that is tested for leachability of target substances, may be either

a prefabricated treated article or a treated article applied to a

substrate

transformation product substance derived from the original substance, e.g. due to

metabolism, hydrolytic or photolytic degradation

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treated article according to BPR 528/2012 Art. 3 (1l) any substance, mixture or

article which has been treated with, or intentionally incorporates, one

or more biocidal products

weathering rack installation to hold the test setups during outdoor exposure

NOTE

A coating material is a product, in liquid, paste or powder form, that, when applied to a substrate,

forms a film possessing protective, decorative and/or other specific properties [EN ISO 4618:2006];

and a coating is a continuous layer formed from a single or multiple application of a coating material

to a substrate.

3 Equipment

3.1 Preparation of test specimens

Equipment suitable to cut panels or pieces from test materials and substrates.

3.2 Application of test materials (optional)

Equipment suitable for carrying out vacuum, vacuum-pressure, immersion or surface treatment of

specimens.

3.3 Balance

A balance capable of weighing to the nearest 0.1 g.

3.4 Condition chamber

Conditioning chamber, well ventilated, controlled at (22 ± 3) °C and (60 ± 10) % relative humidity.

3.5 Preparation of test setups

Devices (e.g. clamps) to attach the test specimens on the weathering rack.

3.6 Exposure site

An open area, free from tall vegetation and not excessively influenced by industrial or agricultural

pollution.

3.7 Weathering rack

The weathering rack, to which the test setups are attached, should be robust to maintain the test

setups in the required orientation for the duration of the test. Racks which have been found to be

suitable are illustrated in Annex A.

All construction materials used to fix and support the test setups (e.g. screws, hookes) and to collect

the rainwater (gutter) shall be inert.

NOTE

Stainless steel has been found to be suitable (see Annex A).

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3.8 Vessel for receiving water

Leachates are collected in coated laboratory glass flasks that are protected from direct solar radiation

or plastic jars with no impurities which can influence the target substances. Channelings have to be

installed close to the test specimens. The receiving vessels are closed allowing only the incoming

water from the weathering rack.

NOTES

Laboratory brown glass flasks are preferred when the preservative contains organic biocides and

plastic jars when the preservative contains inorganic biocides. Plastic jars cannot be used if the target

substances are hydrophobic. It has to be verified that target compounds do not sorb to the plastic jar.

EN ISO 5667-3 gives the good practices to preserve water samples. The brown glass flasks or plastic

jars shall be protected from heat and sunlight. The capacity of the vessels depends on the exposure

scenario. If the expected annual precipitation is approximately 700 mm and the test setup is placed

horizontally 25 l containers are recommended. If the test setups are exposed vertically 5 l containers

are recommended. Depending of the target substances, a preservative may have to be added to the

vessels in order to prevent abiotic and/or biotic degradation.

3.9 Weather station

A weather station capable of monitoring the temperature, quantity of rainfall, the wind direction and

wind speed at the test site continuously shall be used. The kind of precipitation (rain, snow, hail) has to

be noted.

3.10 Refrigerator/Freezer

A refrigerator or freezer (-18 °C or less).

3.11 Chemical analysis equipment

Analytical equipment appropriate to determine the target substance(s) in the leachate.

3.12 Safety equipment and protection clothing

Appropriate for the test product, to ensure the safety of the operator.

4 Test setup

4.1 General

Test setups are prepared from either test specimens from prefabricated test materials or test

specimens prepared by application of a test material (e.g. a coating material) onto a substrate.

The test specimens are representative or typical of commercial treated articles, and exposed to mimic

service exposure. Alternatively the test specimens may be prepared to be a ‘realistic worst case’

estimation of the emission for a treated article under outdoor exposure.

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NOTE

Test specimens of treated articles into which the biocides are usually brought by means of industrial

processes (e.g. impregnation of textiles, treatment of fibres and plastics) have to be obtained as

prefabricated treated articles from these procedures, and shall not be prepared by laboratories

themselves.

4.2 Sampling of test material

The sample of the test material shall be representative of the product to be tested.

Samples shall be stored and handled in accordance with any written requirements from the supplier.

The sampling and conditioning procedure should be recorded in a sampling report

The product shall be analysed for the target substance(s) prior to use if possible.

NOTE

It has to be reported whether the original content of target substance(s) was confirmed or not.

4.3 Preparation of test specimens

4.3.1 Number and size of test specimens

Prepare 2 test specimens for each test or combination of test parameters.

The minimum dimensions of the front face (vertical exposure) or top face (horizontal exposure) are

(760 ± 5) mm in length and (760 ± 40) mm in width.

Alternatively the pieces of treated articles can be prepared in a way typical of commercial practice.

The actual dimensions shall be stated in the test report.

Each test specimen shall be marked to identify it throughout the test.

NOTE

For treated articles that are usually applied on large vertically oriented areas, test results from larger

test specimens (particularly in the vertical dimension) represent use conditions better than results from

test specimens with the proposed dimensions. The defined dimensions can be considered as worst

case situation concerning exposition to rain and amount of runoff per surface area.

4.3.2 Preparation of test specimens from prefabricated treated articles

Test specimens with dimensions given under 4.3.1. are cut from the prefabricated treated articles.

NOTE

It can be necessary to fix pieces of prefabricated treated articles (e.g. textiles) onto appropriate

frames.

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Lateral faces of porous or water absorbing materials are end-sealed by a material which prevents

water entry and damage of the material. The end-sealer shall remain effective during long-term

exposure to the weather and may not contain biocides or other target substances.

Calculate the amount of active substance(s) for each test specimen and express the result in grams of

active substance(s) per square metre of exposed surface area.

4.3.3 Preparation of test specimens from treated articles to be applied to a substrate

4.3.3.1 Substrate

The substrate used to carry the material shall have a homogeneous planar surface, shall be inert and

test products shall adhere well to it during the outdoor exposure. As the substrate can influence the

results, it shall be stated in the test report.

NOTES

See examples for substrates in Annex A.

Substrates might influence the leaching (e.g. concrete, mineral renders and fibre cement board and

wood substrates).

The test material has to be intended for the selected substrate, e.g. coatings have to be stable

towards alkalinity if fibre cement is selected as substrate.

4.3.3.2 Preparation of substrate panels for test specimens

Cut panels of the substrate with dimensions given under 4.3.1.

4.3.3.3 Application of test material

Test materials have to be applied on substrates according to the manufacturers instruction.

NOTE

Apply the maximum amount if a range is given for the application of a coating material.

The substrate shall be clean and dry. The substrate shall be coated with the test material in the

specified quantity in accordance with the recommendations of the manufacturer. Determine and record

the total mass applied.

The test material is applied only to the exposed front face if the test specimen is intended to be

installed vertically on the weathering rack.

The test material is applied to the exposed top face and the lateral faces if the test specimen is

intended to be installed horizontally on the weathering rack. In this case the surface areas of the

lateral faces are included in the calculation of area-based emissions.

Follow the supplier’s instructions for applying surface coating or water-repellent treatment.

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Lateral faces of porous or water absorbing materials substrate panels are end-sealed by a

weatherproof material which prevents water entry and damage of test specimens if they are intended

to be exposed vertically. The end-sealer shall remain effective during long-term exposure to the

weather and may not contain biocides or other target substances.

Calculate the amount of target substance(s) for each test specimen and express the result in grams of

target substance per square metre of exposed surface area if appropriate.

Reject any test specimen with amounts of test material deviating by more than 5 % from the average

for that type of test specimen and substitute an appropriate alternative which falls within this range.

4.3.3.4. Conditioning

Condition the test specimens with freely circulating air without UV influence and without exposure to

rain for a period agreed with the manufacturer.

NOTES

If no details are provided by the manufacturer the conditioning period should be 1-2 weeks.

A process which has been found to be suitable is to dry the treated test specimens in a well-ventilated

area protected from rain and frost and a maximum temperature of 30 °C.

Follow the supplier’s instructions for applying surface coating or water-repellent treatment.

Use an inert material as glass or stainless steel to support the test specimens. The test specimens

may not touch each other.

Note the period from treatment to installing the test setups to the weathering rack.

4.4 Preparation of test setups from test specimens

Install devices (e.g. clamps) to attach the test setups on the weathering rack.

5 Test procedure

5.1 Exposure test site

The test is valid using one test site; however, it may be advantageous to select more than one test site

representing markedly different climatic conditions. Place the test setups on the weathering rack (see

Annex A). The test setup can be exposed horizontally or vertically depending on the data required.

The vertically exposed test setups shall be orientated to reflect the most severe weather conditions

concerning wind, rain and sunlight. This has to be justified in the test report.

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NOTES

It has to be assured that vertically exposed test specimens from the same experiment are exposed to

the same amount of driving rain.

Data required: if the intended use includes horizontal exposure, test data on horizontal exposure are

required.

The applicant is free to deliver additional emission data conducted by various orientations of the test

racks.

Recommendations on the installation of test specimens and descriptions of climatic conditions are

given in DIN EN ISO 2810:2004.

5.2 Duration of the test

The minimum duration of the assessment period is two years. A minimum number of 5 data points in

the first year and a minimum number of 3 data points in the second year are required.

NOTES

A mean annual precipitation for Europe of 700 mm is considered to be an optimum, but will not be

reached at each site. The aim is to have sufficient data points to allow extrapolation in order to

estimate long term leaching for the service life.

It has to be justified if an experiment is finished earlier than the two years.

5.3 Collection of the leachates

The leachate shall be sampled after each significant rain event or after the required sampling period.

The time and the date are recorded.

The sampling period should be increased to larger intervals but a short sampling period in the

beginning is known to be suitable. Sampling periods can be increased depending on the duration of

the test. The first sampling period shall not exceed 50 mm of precipitation.

NOTE

The amount of snow is given as the corresponding amount of water (determined for melted snow).

Any signs of microbiological growth in the leachate or on the test specimens shall be recorded in the

test report.

Leachates from different rain events within a sampling period can be bulked. Samples of the leachate

from the sampling periods may be stored (e.g. 1 l).

NOTES

The frequency of leachate collection has to be decided by the laboratory depending on the volume of

runoff samples, stability of target substances, anticipated weather conditions.

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The amount of leachate can be large and it can be advantageous to store only a few percent of the

leachate. The same percentage of leachate shall be sampled and stored after each rain event.

Samples should be stored under conditions that preserve the compounds of interest, e.g. in a

refrigerator or in a freezer in the dark to reduce degradation of the target substances and microbial

growth in the sample before analysis (see Annex B). The storage procedure shall follow

recommendations from the supplier of the product or EN ISO 5667-3.

NOTES

Use available information or preliminary stability tests to decide on an appropriate storage method.

Guidance on the preservation and handling of water samples is given in EN ISO 5667-3.

These conditions have to be convenient with the nature (organic, inorganic compound) of the target

substance(s). A maximum time of storage before the analysis should be defined. The leachate is

stored in a freezer at a temperature below -18 °C after, for example, acidification for inorganic

compound or extraction for organics.

5.4 Chemical analysis

Chemical analysis of the collected leachates is conducted after a planned time schedule, e.g. after

increasing sampling periods.

NOTE

This is an example of a schedule: 0-20 mm, 20-50 mm, 50-100 mm, 100-200 mm, 200-300 mm, 300-

500 mm, 500-700 mm, 700-900 mm, 900-1100 mm and 1100-1400 mm of rain.

The validity of the analytical method for the target substances shall be determined before conducting

the test:

a) accuracy;

b) specificity;

c) limit of detection;

d) limit of quantification;

e) precision

(See also Annex B)

It has to be reported if the analysed substances are stable during storage of the runoff samples until

chemical analysis. It has to be included in the test report if there are data on limited stability of

analysed substances in water.

6 Results

6.1 Results in concentrations

Express the analytical results as concentration c of each target substance analysed in the merged

leachate for each sampling period in milligram per litre.

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6.2. Results in terms of emissions Convert the analytical results cp for the leachates from the sampling periods expressed in milligram

per litre to emissions E in milligram per square metre for each sampling period p (e.g. 0-50 mm, 50-

100 mm) with

Equation (1) 𝐸𝑝 = 𝑐𝑝 ×𝑉𝑝

𝐴

where

p is the running number of the sampling period;

Ep is the emission during the sampling period p, in milligram per square metre;

A is the exposed surface area of the test specimen, in square metre;

cp is the measured concentration of the target substance in the merged leachate of the sampling

period p, in milligram per litre;

Vp is the real volume of the merged leachate after the sampling period p, in litre.

NOTE

The exposed surface area of the test specimen is defined as

a) surface area of top face and lateral faces, e.g.

(0.76 m × 0.76 m + 4 (0.76 m × width of lateral faces) = (0.5776 + x) m²

. for horizontally exposed test specimens

b) surface area of the front face, e.g.

(0.76 m × 0.76 m) = 0.5776 m²

for vertically exposed test specimens.

.

Calculate the cumulative emission during the total time of the test according to Equation 2.

Equation (2) 𝐸 = ∑ 𝐸𝑝𝑛𝑝=1

where

E is the cumulative emission during the total time of the test, in milligram per square metre;

Ep is the emission during the sampling period, in milligram per square metre;

p is the running number of the sampling period

n is the number of the final sampling period

Additional assessment shall be done, for example the percentage of leaching.

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7 Test report

The test report shall contain at least the following information:

a) reference to this guidance document;

b) specific and unique name or code of the treated article, the trade or common name of the

active substance(s), substances of concern (as defined in the Regulation (EU) No 528/2012);

c) all details necessary to identify the test material;

d) name of the organisation responsible for the test report and the date of issue;

e) name(s) and signature(s) of the persons responsible;

f) date of order, the name and address of the sponsor of the test;

g) results of chemical analysis of the biocides in the test material;

h) conditioning and sampling of the test material;

i) solvent or diluents used (if applied);

j) material of the substrate for application of test materials*;

k) number and dimensions of the test specimens;

l) method and date of application of the test material*;

m) individual and mean amount of test material on the substrate panels in grams or millilitres per

square metre as appropriate*;

n) method and drying time after application of the test material and details of post treatment*;

o) method and duration of conditioning or storage of the test specimens;

p) amount of target substances in the test specimens in milligrams per square metre exposed

surface area;

q) location (latitude, longitude and elevation) and detailed description of the exposure site(s)

including information on temperature and rainfall (precipitation);

r) date and installation of the test setups;

s) date of collection of each leachate and the corresponding amount of rainfall for each sampling

period in millimetres;

t) duration of the sampling period(s);

u) conditions of storage of the leachate prior to chemical analysis;

v) analytical methods used to determine target substances in the merged eluates;

w) time schedule for chemical analysis of the collected leachates.

x) information on the stability of the analysed substances during storage of the eluates prior to

analysis;

y) leaching in milligram per square metre exposed material for the sampling periods;

z) any deviations from this standard and any special factors which may have influenced the

results.

* information is not necessary when the test specimen is a prefabricated treated article

It is recommended to add graphs that represent the cumulative emissions of each target

substance in milligram per square metre versus the amount of rain in millimetres.

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Annex A (informative)

Test setup and weathering rack

Figure A.1 Example for a test setup for vertical exposure (plan and sectional view)

The width of the gutter and the distance between the gutter and the lower edge of the test specimen have to be optimised in a way that runoff cannot be lost at high wind speeds and test specimens cannot not dip into snow.

Figure A.2 — Example for a test setup for horizontal exposure (sectional view)

Test specimens have to be installed slightly downgraded to ensure that water runs into the collecting container.

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2

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1 test set-up2 stainless steel tray3 laboratory glass flask to sample runoff

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Examples of test setups and weather racks at a field test area

Figure A.3 — Vertically oriented test setups

Figure A.4 — Horizontally oriented test setup

Examples for substrates

Substrate Treated article

XPS (extruded polystyrene) Coating materials, e.g. paints and renders

EPS (expanded polystyrene) Coating materials, e.g. paints and renders

weather-proof glued plywood paints for wood

solid wood paints for wood

fibre cement roof paints

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Annex B (informative)

Stability study

Prepare a reference sample with defined amounts of target substances in water if possible. Water is

spiked with the substances in question so that the concentration is in the range expected in the test.

Alternatively, the first runoff sample can be spiked with target substances and used as reference

sample.

Store the reference sample under the same conditions as the runoff sample.

Analyse the reference sample in parallel with the runoff samples from the experiment.

Check and report the stability of the target sample.

Limit of detection/quantification:

The analytical method is developed and different calibration solutions (at different concentrations) are

analysed. The quantification limit is chosen to be the concentration of the most diluted calibration

solution which gives a good correlation.

Recovery:

A triplicate recovery experiment is performed at two levels: just above the quantification limit and at a

concentration, which is expected to be close to maximum concentrations that will be found during the

study.

Bibliography

Regulation (EU) No 528/2012 of the European Parliament and of the Council of 22 May 2012

concerning the making available on the market and use of biocidal products. http://eur-

lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2012:167:0001:0123:EN:PDF

Nordtest Standard NT Build 509: NORDTEST Method Leaching of active ingredients from

preservative-treated timber – Semi-field testing

CEN/TR 16663:2014: Durability of wood and wood-based products - Determination of emissions from

preservative treated wood to the environment - Wooden commodities exposed in Use Class 3 (Not

covered, not in contact with the ground) - Semi-field method

DIN EN ISO 2810:2004: Paints and varnishes. Natural weathering of coatings. Exposure and assessment (ISO 2810:2004)

EN ISO 5667-3:2003: Water quality – Sampling, Part 3: Guidance on the preservation and handling of

water samples