LIMIT VALUES FOR VOC EMISSIONS FROM CONSTRUCTION AND DECORATIVE PRODUCTS AROUND THE GLOBE

Transcription

1 Topic B14: Policy, Standards and regulations LIMIT VALUES FOR VOC EMISSIONS FROM CONSTRUCTION AND DECORATIVE PRODUCTS AROUND THE GLOBE Stephany I. MASON 1,*, Reinhard C. OPPL 2, Caroline LAFFARGUE 2 1 Eurofins Air Toxics, Inc. - Product Testing North America, Folsom, CA, USA 2 Eurofins Product Testing A/S, Galten, Denmark * Corresponding voc@eurofins.com Keywords: VOC emissions, LEED, BREEAM, Labels, EN SUMMARY Volatile Organic Compound (VOC) emissions from construction products and decorative products can contribute to indoor air pollution for some time period after the completion of building construction. Several low VOC rating systems contain restrictions on VOC emissions into indoor air after their installation indoors, but the limit values differ, and some of the testing and modeling parameters are not harmonized. Other programs limit the VOC content of liquid products before they are applied, mainly for reducing the impact of emitted VOCs on urban smog formation. An analysis of the most often used low VOC specifications shows both obstacles and opportunities for harmonization. This overview can help specifiers and regulators to establish meaningful low VOC requirements without re-inventing the wheel. INTRODUCTION Volatile Organic Compound (VOC) emissions from construction products and decorative products can contribute to indoor air pollution for some time period after the completion of building construction. Several low VOC rating systems contain restrictions on VOC emissions into indoor air but the limit values differ, and some of the testing and modeling parameters are not harmonized. Other programs limit the VOC content of liquid products before they are applied, mainly for reducing the impact of emitted VOC on urban smog formation. These limits influence the way impacted products are manufactured. Those programs that obtained a significant position as purchase criteria will influence how easily low VOC products can access the different markets. METHODS VOC emissions are limited by legislation in several European countries. In addition, special regulations are in place for formaldehyde emissions in several more countries. And the VOC content of paints and coatings also is regulated in a number of countries. A large number of voluntary labels around the globe specify low VOC emissions criteria (e.g., Blue Angel, EMICODE, FloorScore, Indoor Air Comfort, GREENGUARD, Indoor Advantage, M1). The same applies to programs for sustainable buildings (e.g., LEED, BREEAM, CHPS, DGNB, GreenStar) or products (e.g., Cradle-to-Cradle), and related standards (e.g. EN 15251, AHSRAE 189.1, IgCC).

2 All these programs contain restrictions on VOC emissions into indoor air but the limit values differ, as do some of the testing and modeling parameters (Laffargue et al. 2014). The variety of VOC limits creates the need for many different tests as long as no harmonization exists between the regulations, and between the other programs. This is a significant cost burden for companies if they distribute construction products or decorative products in more than one country. The requirements of the frequently used low VOC rating systems were identified and compared in terms of limit values, test methods, and implementation procedures. RESULTS VOC Emissions Limits VOC emissions limits target the exposure of the end-user after installation of the product indoors. Exposure of the installer is not covered. Emissions are assessed by simulating standardized real exposure with the help of a reference room (also called exposure scenario) of fixed dimensions, environment (temperature and relative humidity), and ventilation. Testing is not performed in the reference room, but in a smaller test chamber that simulates the reference scenario. The acquired emission rates are calculated back to air concentrations (µg/m³) in the standard exposure setting. Only the Finnish M1 label specifies limit values as area specific emission rates per square meter of product, and per hour. VOC emissions from building materials and products typically decrease over time, see Figure 1. In the US, it is commonly assumed that emissions after 14 days are a reasonable indicator of long-term emissions into indoor air (CDPH, 2010). In Europe, an emissions test after 28 days storage of the test specimen in a ventilated test chamber serves the same purpose (ECA, 2005). In German speaking countries, a supplemental emissions test after 3 days is also considered to simulate initial higher exposure in the case of early re-occupancy after renovation work is finished. VOC content, however, does not correlate with VOC emissions into indoor air at a set point in time after application of an interior coating. The reason being that VOC content data does not allow to predict the shape of the emissions decay curve. Figure 1: Time decay of emissions and measurement points.

3 The allowable emissions limit values are different per country and per legislation or voluntary labeling program. Most programs set a limit for Total Volatile Organic Compounds (TVOC). Even though there is no toxicological significance for such limitations, this parameter is selected to limit the overall emissions that may include both restricted and non-restricted individual substances. The TVOC parameter also is meant to cap any health impact of the combined exposure to mixtures which commonly contain tens of different VOCs at the same time. Often there are also limit values for formaldehyde emissions after 14 days (US) or 28 days. These limits have a wide range of values. This reflects the ongoing controversy regarding (1) whether the carcinogenicity of formaldehyde has been proven as fact, and/or (2) whether the cancer in question is one of the few cancers with a safe limit below which the human body can defend itself and repair impaired cells. Actual limit values vary between 9 µg/m³ and 120 µg/m³ in the reference rooms, at 14 and 28 days, respectively. Additionally, some legislation and labeling programs include individual limit values per substance. These may be based on direct toxicological studies, where available. However, in most cases such studies are not available. In these situations, some programs use extrapolation from occupational exposure to airborne contaminants over 8 hours/day during 40 hours/week, to lifetime exposure up to 24 hours/day, 7 days/week, including more sensitive populations (children, sick people etc.) than typically accounted for in workplaces. The extrapolation is done by application of safety factors. As a default assumption, occupational exposure limits are divided by 10 for longer exposure duration, and by another factor of 10 to cover sensitive people. But these factors can be different per specific substance. The best known list of such derived VOC limits for evaluation of VOC emissions by chamber testing are the LCI values (Lowest Concentrations of Interest). Created in 1997 by a European research project, these have been modified and implemented in German regulations (AgBB / DIBt). A different list of LCI values was created in France (AFSSET), but was not adopted as such into French regulation. A pan-european list of LCI values has also been developed in another European research project (ECA 2012 and ECA 2013). Other lists are in use by the French regulation on compulsory labeling of the VOC emissions class, by the California CDPH Standard Method, and several other local programs. A few of the regulations and programs that contain many such individual VOC limit values also include the so-called R value. This value is obtained for a test result by summing the ratios of the calculated concentration in the reference room by the LCI value for each detected VOC. The total must not exceed 1.0, corresponding to 100% of the allowed emissions: R = Σ (c i / LCI i ) (1) where R is the R or risk value, Σ is the sum over all measured VOCs, c i is the concentration of each VOC i and LCI i is the associated LCI limit value. Some regulations and programs in German speaking countries also set a limit for Total Semi- Volatile Organic Compounds (TSVOC) with the intention of having a stringent limit for substances with very low vapor pressure. These are emitted into indoor air over a much longer time period than VOCs. See Tables 1 and 2 for an overview of the various VOC emissions limits.

4 Table 1: Examples of VOC emissions limit values, given in µg/m³ in the air of the reference room or exposure scenario, if not specified otherwise. Parameter TVOC Tested / evaluated after 3 days German DIBt: 10,000 Blue Angel, EMICODE, IAC: 1000 or lower Tested / evaluated after 14 days US CDPH: no limit, but value is reported US GREENGUARD Gold: 220 TSVOC Formaldehyde Acetaldehyde Individual VOC limit values US CDPH, GREENGUARD Gold: 9 US CDPH, GREENGUARD Gold: 70 US CDPH: CREL list GREENGUARD Gold: CRELs and TLVs R value Sum of VOCs without LCI *: Regulation planned to be published during March 2014 Tested / evaluated after 28 days German DIBt: 1000 France: per class (A+: 1000) Belgium*: 1000 Blue Angel, EMICODE, IAC, M1: 300 or lower German DIBt: 100 France: Belgium*: 100 Blue Angel, EMICODE: 50 or lower IAC: 10 German DIBt: 120 France: per class (A+: 10) Belgium*: 100 Blue Angel, EMICODE, IAC, M1: 60 or lower Belgium*: 200 France: per class (A+: 200) Blue Angel, EMICODE, IAC: 60 or lower. DIBt: AgBB LCIs France: 8 VOCs Belgium*: EU LCIs Blue Angel, EMICODE EC1 PLUS, IAC: Now AgBB LCIs, later possibly EU LCIs German DIBt, Belgium*, Blue Angel, EMICODE EC1 PLUS, IAC: 1.0 (dimensionless) German DIBt: 100 Blue Angel, EMICODE EC1 PLUS, IAC: 50 or lower As long as the basic testing conditions are the same (temperature, relative humidity), or similar (loading factor, ventilation), one single VOC emissions test can be used for evaluating product emissions against most of these regulations and voluntary labeling programs (Augustin and Oppl, 2009). Regulations in Japan and in South Korea require different testing temperatures (28 C and 25 C, respectively versus 23 C in Europe and the US). This makes it impossible to compare emissions test data between these regions.

5 Table 2: More examples of VOC emissions limit values, given in µg/m³ in the air of the reference room or exposure scenario, if not specified otherwise. Parameter Carcinogenic VOCs, categories C1A and C1B Tested / evaluated after 3 days German DIBt, Blue Angel, EMICODE, IAC: Tested / evaluated after 14 days US CDPH: no limits, but CA Prop65 compounds are Tested / evaluated after 28 days German DIBt, Belgium*, Blue Angel, EMICODE, IAC: 1 France: Limitation of 4 specific CMR VOCs 10 reported Danish Indoor Air Climate Label: Below irritation limits (as in a special Irritating VOCs database) Ammonia M1 (Finland): 30 µg/m²h Odour, ISO , acceptance scale Odour, ISO , intensity, hedonics M1 (Finland): 0.0 (dimensionless) ; under development for German Blue Angel Table 3: Abbreviations used in Tables 1 and 2: AgBB German governmental Committee for Health-related Evaluation of Building Products Belgium* Planned Belgian regulation, to be implemented 2015, but not yet published as of January 2014 CMR Carcinogenic, mutagenic or reproductive toxic substances CDPH California Department of Public Health Standard Method (SM v1.1) CREL Chronic Reference Exposure Levels DIBt German Institute for Competence in Civil Engineering EMICODE Low VOC emissions label for installation products (adhesives, sealants and more) EU European Union IAC Indoor Air Comfort - low VOC emissions label for construction and decorative products LCI Lowest Concentration of Interest M1 Finnish Low VOC emissions label for construction and decorative products R Risk value VOC Volatile Organic Compound(s) SVOC Semi-Volatile Organic Compound(s) TLV Threshold Limit Value TSVOC Total Semi-Volatile Organic Compounds TVOC Total Volatile Organic Compounds Formaldehyde Emissions Limits Formaldehyde emissions of wood-based products are based on a specific reaction of the binder normally used for composite wood products, e.g. plywood, with water contained in the surrounding air as humidity. This reaction leads to continuous release of formaldehyde, reaching equilibrium after several days. The same applies to some mineral wool products if a similar binder is used. European testing standard EN determines the emissions decay over time, over a minimum of 10 days, and the stable, so-called steady-state concentration. If the emissions level is not stable

6 within four weeks after the start of the test then the extrapolated emissions at 28 days are used as the test results, comparable to the general VOC emissions testing schedule in Europe. Though some regulations and voluntary labels also require EN formaldehyde testing for other products, the results are circumspect because these steady-state emissions do not occur with products not containing that specific type of binder. In these situations, it is more appropriate to test for formaldehyde emissions following CEN/TS and the ISO standards. In the US, formaldehyde emissions from composite wood products are tested to determine the steady-state concentrations following the primary standard ASTM E1333 and the secondary standard ASTM D6007. For other product types, testing following the CDPH Standard Method, or equivalent, is more appropriate. VOC Content Limits Traditionally, VOC content limits are applied to products that are liquid or viscous (i.e. wet) when applied on a construction site, such as paints, coatings, adhesives and sealants. These limits were originally established to protect urban outdoor air against the contribution of VOCs to smog formation. There are related regulations in place in several Federal States of the USA, in all member States of the European Union via the so-called Decopaint Directive (EC2004/42), and in a number of other countries. All these set upper limits for the VOC content of numerous types of coatings. There are also VOC content limits that apply to adhesives and sealants, such as the SCAQMD regulations in the Los Angeles region of California. While VOC content may loosely correlate with initial VOC emissions during application of wet products, it does not correlate with VOC emissions into indoor air during occupancy (Figure 1). Nevertheless, when LEED requirements for low emitting interiors were initially developed, VOC content limits were the only available VOC limits for these types of products. The new LEED version 4 retains the VOC content limits. However, taking into account that VOC content limits do not protect against potentially high VOC emissions after building completion, LEED v4 now also requires compliance with VOC emissions limits for paints, coatings, adhesives and sealants. The European ecolabel for paints and coatings, the Blue Angel for lacquers and for wall paints, BREEAM International, and Green Seal continue to have only VOC content limits for paints and coatings. In Europe, compliance with the legal requirements set in the Decopaint Directive (EC2004/42) will also suffice for most of these additional specifications. Essentially, there are two types of tests methodologies employed to determine the VOC content of wet products. The first method, e.g. ASTM D2369 and ISO , is based on the measured weight loss observed upon drying the product at 110 C for 60 minutes. This is the most commonly employed method in the US, while in the EU, this method is only employed for reactive coatings, and for coatings with >15% VOC by weight. The second method, e.g. ASTM D6886 and ISO , employs direct injection of a sample into a GC/FID or GC/MS system, whereby the individual VOCs are quantified and totaled to obtain the VOC content. This methodology can also be used to determine the presence and quantity of exempt compounds and/or solvents. In the US, this method is used primarily for low VOC content (<5%) waterborne coatings. In the EU, this is the more commonly applied methodology.

7 It should be noted, however, that there are two important differences between how the test methods and results are evaluated in Europe and in the US. These are: 1) how water is handled and 2) the consideration, or not, of exempt compounds (Figure 2). In the US, the regulated VOC content is determined based on the volume of the coating minus the water volume. In the EU, the water volume is not subtracted out of the product volume. Thus, in the US, modern water-based paints are rated down because the water volume is not included, which results in much higher VOC content levels than determined following the European approach. This apparent promotion of water-free products contradicts the original ambition of promoting lowsolvent products. Additionally, as the VOC content limits are related to the prevention of urban smog formation, in essence there are two classes of VOCs. The designated Exempt VOCs do not promote urban smog and, thus, are excluded from the calculation of VOC content in the US. As a consequence, there are, for example, adhesives in the US that are formulated on the basis of acetone, a listed exempt VOC. In Europe such products would meet opposition by occupational hygienists due to the risks associated with health impacts, and the risk of explosion when used in closed rooms. Consequently, in the EU, VOC content is determined based on all VOCs in the volume of the product, including the volume of water. Alternately, in the US, VOC content is calculated based on only the non-exempt VOCs in the volume of product less water, i.e. the volume of the solids and non-exempt VOCs. See Figure 2. These differences hinder a direct comparison of VOC content data obtained in Europe and in the US, making compliance difficult for international manufacturers who operate on several markets. Figure 2: Different VOC content determinations in Europe and in the USA. Finally, when discussing VOCs and products, it is important to define which substances are considered VOCs. The European Decopaint Directive (EC2004/42) considers all substances with a boiling point greater than 250 C as non-voc, whereas the California SCAQMD regulation sets this limit at 280 C, thus, including more substances in the VOC definition. And, the upper limit for VOC emissions testing is even higher: 287 C for most testing methods (but 302 C for the

8 California CDPH Standard Method). Expansion of ISO to include SVOC content determination is in preparation. CONCLUSIONS An analysis of the most often used low VOC specifications shows both obstacles and opportunities for harmonization. Knowledge about, and making comparisons of, existing specifications can help specifiers and regulators to establish meaningful low VOC requirements without re-inventing the wheel. When new regulations are established, e.g. in more countries, if they do not deviate systematically from the international state-of-the-art as described in this paper, export industries can more readily be supported. Only then, compliance reports for national VOC limit values can be used on the international level without additional testing efforts. REFERENCES Laffargue C, Oppl R, Mason S (2014) Harmonization of VOC Emissions Testing in Europe the new Standard CEN/TS 16516, Proceedings of Indoor Air Conference, Hong Kong 2014 Augustin R, Oppl R (2009) Product certification a new tool for good indoor air quality. Gefahrstoffe - Reinhaltung der Luft 69 (2009) Nr. 3, CDPH (California Department of Public) (2010): Standard Method for the Testing and Evaluation of Volatile Organic Chemical Emissions from Indoor Sources Using Environmental Chambers Version 1.1 ECA (European Collaborative Action, Urban Air, Indoor Environment and Human Exposure) (2005): Harmonisation of indoor material emissions labelling systems in the EU, Inventory of existing schemes, Luxembourg: Publications Office of the European Union. Report No. 24, EUR EN. Please note: Several references in this report are outdated. ECA (European Collaborative Action, Urban Air, Indoor Environment and Human Exposure) (2012): Harmonisation framework for indoor material labelling schemes in the EU, Luxembourg: Publications Office of the European Union. Report No. 27, EUR EN. ECA (European Collaborative Action, Urban Air, Indoor Environment and Human Exposure) (2013): Harmonisation framework for health based evaluation of indoor emissions from construction products in the European Union using the EU-LCI concept, Luxembourg: Publications Office of the European Union. Report No. 29, EUR EN. As the list of references for all the involved low VOC regulations and programs is very long, this will be made available by the authors upon request.