Health-related evaluation procedure for volatile organic compounds emissions

evaluation scheme from the AgBB)

In order to be able to assess the pollution of indoor air through the emission of volatile and semi-volatile organic substances from construction products, the Ausschuss zur gesundheitlichen Bewertung von Bauprodukten ('Committee for Health-Related Evaluation of Building Products' – AgBB)²¹ has developed an evaluation scheme [21] which is based on the European ECA Report No. 18 "Evaluation of VOC emissions from building products" [89].

The AgBB's VOC/SVOC evaluation scheme was published for the first time in 2000 and will be assessed and, if need be, adapted following the two-year introductory phase from 2002 to 2004. An English version of the AgBB's evaluation scheme can be downloaded from the Internet at http://www.umweltbundesamt.de/uba-info-daten-e/daten-e/voc.htm.

The VOC/SVOC evaluation scheme provides a procedure for the evaluation of the health effect of VOC and SVOC emissions from construction products that are used in the interiors of buildings. The scheme defines volatile organic compounds (VOC) as compounds with a gas chromatographically determined retention range of C₆ to C₁₆, which can be determined as individual substances or as total parameters (TVOC = Total Volatile Organic Compounds).

It defines semi-volatile organic compounds (SVOC) as compounds with a gas chromatographically determined retention area > C₁₆ to C₂₂. In deviation from these definitions, the WHO (World Health Organisation) classifies organic compounds according to their boiling point, as a result of which the different groups are not defined in a very clear way [90]:

21 The AgBB was founded in 1997 by the Länderarbeitsgruppe "Umweltbezogener Gesundheitsschutz"

(‘Federal States Working Group on Environment-related Health Protection‘ – LAUG) of the Arbeitsgemeinschaft der Obersten Landesgesundheitsbehörden (Permanent Working Group of the Highest State Health Authorities – AOLG). In addition to the health authorities of the Länder, the AgBB includes the Umweltbundesamt (‘Federal Environmental Agency’ – UBA), the Bundesinstitut für gesundheitlichen Verbraucherschutz und Veterinärmedizin (Federal Institute for Health-related Consumer Protection and Veterinary Medicine – BgVV), the Deutsches Institut für Bautechnik (German Institute for Building Technology – DIBt), the Konferenz der für Städtebau, Bau- und Wohnungswesen zuständigen Minister und Senatoren der Länder (Conference of the State Ministers and Senators for Town Building, Building and Housing Affairs – ARGEBAU), the Bundesanstalt für Materialforschung und –prüfung (Federal Institute for Materials Research and Testing – BAM) and the Koordinierungsausschuss 03 für Hygiene, Gesundheit und Umweltschutz des Normenausschusses Bauwesen im DIN (Co-ordinating Committee 03 for Hygiene, Health and the Environment’ of the Building and Civil Engineering Standards Committee within DIN – DIN-KOA 03).

• Very volatile organic compounds (VVOC) with boiling points between 0 to 50 - 100 °C

• Volatile organic compounds (VOC) with boiling points between 50 - 100 to 240 - 260 °C and

• semi-volatile organic compounds (SVOC) with boiling points between 240 - 260 to 380 - 400 °C.

The release of volatile and semi-volatile organic compounds is determined using test chamber measurements. Here the scheme makes use of the European test standards DIN EN 13419 Part 1 - 3 (Draft) for determining the emission of VOC from construction products [91, 92, 93]. Parts 1 and 2 of the standard respectively describe the procedure when using a test chamber (Part 1) and a test cell (Part 2). Part 3 specifies the procedures for sampling, storing samples and preparing the test specimens. By specifying the test chamber conditions such as the air change, temperature and surface area of the test specimen, the intention is to achieve test chamber results that largely correspond with an actual room situation. The volatile organic compounds are analysed using standard ISO 16000-6, which, after final approval, is intended to be adopted as ENV 13419, Part 4 [94].

The evaluation of the emitted VOC and SVOC is carried out either with the help of LCI values (Lowest Concentration of Interest) for individual substances or by limiting the total parameters for TVOC, SVOC and the sum of the so-called "non-assessable compounds".

The LCI values are derived from workplace limit values, the so-called maximum workplace concentrations (Maximale Arbeitsplatzkonzentrationen – MAK values). The different conditions in general indoor spaces and workplaces such as, for example, continuous exposure, existence of risk groups and the undefined total exposure in indoor spaces are taken into account when establishing the LCI values by dividing the MAK values as a general rule by 100. Greater value is given to possible carcinogenic substances according to Category 3 of Council Directive 67/548/EEC [3] by dividing the MAK value as a general rule by 1000. LCI values determined in this manner should be understood as calculated values and not as guideline values for indoor air that are sufficiently well-founded in toxicological terms. Carcinogenic substances and those with a suspected carcinogenic potential (Category 1 and 2 of Council Directive 67/548/EEC) [3] are evaluated separately. Mutagenic and reprotoxic substances are subject to individual examination²².

The LCI list is revised and published roughly once a year according to need and currently comprises 138 compounds (as of June 2003). These are divided into the following substance groups:

• Aromatic hydrocarbons (31 compounds)

• Saturated aliphatic hydrocarbons (n, iso and cyclo-) (7 compounds)

• Terpenes (5 compounds)

• Aliphatic alcohols and ethanols (13 compounds)

• Aromatic alcohols (phenols) (2 compounds)

• Glycols, Glycolethanols, Glycolesters (12 compounds)

• Aldehydes (18 compounds)

• Ketones (9 compounds)

• Acids (9 compounds)

22 CMR substance, Category 1 according to Council Directive 67/548/EEC: substance that is known to have a carcinogenic, mutagenic or reprotoxic effect on humans.

CMR substance, Category 2 according to Council Directive 67/548/EEC: substance that should be viewed as having a carcinogenic, mutagenic or reprotoxic effect on humans.

Approximately 850 substances are currently classified as CMR substances according to Category 1 and 2 (Council Directive 67/548/EEG) [95].

• Esters and Lactones (22 compounds)

• Chlorinated hydrocarbons (1 compound)

• Others (9 compounds)

The current list of the LCI values can be found in Annex A10.

In addition to the health-related evaluation of the VOC and SVOC emissions from construction products, the VOC/SVOC evaluation scheme is also intended to be used for recording sensory aspects, as odour emissions often have an adverse effect on the building users. Due to the lack of uniform testing methods and evaluation criteria, however, it has not yet been possible to integrate this aspect into the evaluation scheme, although it is currently being worked upon.

The procedure used by the AgBB evaluation scheme

The start of the test for measuring emissions (t0) is defined as the time at which the product to be tested is unwrapped from the airtight packaging and placed in the test chamber or cell.

The test specimen remains in the emission test chamber or cell over the entire duration of the test.

The TVOC₃ value is determined after testing for 3 days. In order to fulfil the demands of the scheme, the TVOC₃ value must be < 10 mg/m³. In addition, the sum of the detected carcinogenic substances according to Category 1 and 2 of Council Directive 67/548/EEC [3]

must be < 0.01 mg/m³.

In order to assess the long-term emission behaviour, the TVOC₂₈ value is determined again after 28 days. This must not exceed 1 mg/m³. Furthermore, the sum of all SVOC must not be greater than 0.1 mg/m³. After 28 days, the sum of all carcinogenic substances (Category 1 and 2 of Council Directive 67/548/EEC) may not exceed a value of < 0.001 mg/m³. In addition to assessing the total sum of all volatile organic compounds using the TVOC, the individual substances are also assessed after 28 days. Here, all volatile organic compounds are identified and quantified whose concentration is > 2 µg/m³. However, LCI-based evaluations only consider substances whose concentration is > 5 µg/m³. To assess individual substances, the ratio (R_i) of the chamber concentration of i (C_i) to the LCI value is established for each compound (i).

R_i = C_i/NIK_i

If the sum of the quotients for the individual compounds does not exceed 1, it is assumed that these substances have no adverse effect on health.

R = sum of all Ri = sum of all quotients (Ci/NIKi) < 1

For all volatile organic compounds which cannot be identified or do not have an LCI value, it has been determined that the sum of these compounds may not exceed 0.1 mg/m³. The reason behind this criterion is the substitution problem; the intention is to avoid new substances that are not toxicologically assessed being increasingly used as soon as a substance has to be labelled as dangerous.

The following flow chart clarifies the procedure described for assessing VOC and SVOC emissions from construction products:

Fig. 4: Flow chart showing the health-related evaluation of VOC and SVOC emissions from construction products from the AgBB (valid for the introductory phase 2002-2004) [21]

6.1.2 DIBt approval guidelines for the health-related evaluation of indoor