QMT Features: January 2010
Emission testing a burden?
New European regulations will require manufacturers of construction products to undertake chemical emissions testing. Dr Gavin Davies, Markes International, discusses the implications for manufacturing industry

European regulatory requirements relating to construction products and the indoor environment are currently undergoing major review. When the legislation is finalised it is expected that manufacturers will be required to implement chemical emission testing for a wide range of construction materials, decorative products and furnishings as part of the CE marking process. Both testing by accredited third party laboratories and routine, in-house quality control (QC) of emissions may be required.

Since 1989 ‘Essential Requirement’ (ER) 3 of the EC Construction Products Directive (CPD) has required that chemical emissions from products used indoors must not adversely effect the indoor environment or the health & comfort of building occupants. A wide range of structural and decorative materials are covered by this legislation but ER3 was not properly implemented for many years, largely due to the lack of suitable and broadly applicable (‘horizontal’) test methods.

Current legislative activity is changing this situation. In 2005 European Council mandate M/366 was adopted under the CPD and required the European standards agency CEN to finalise and validate methods for testing chemical emissions. A new CEN TC (351) was set up to complete the task with the aim of making chemical emissions testing a mandatory part of CE marking for construction products across Europe. This process is now well underway and has been reinforced by the promulgation of new German and French national regulations requiring emissions testing and establishing performance criteria for product approval.

In parallel with the ongoing work in CEN TC351, European legislators have been developing a replacement to the old 1989 Directive. The new Construction Products Regulation (CPR) could be implemented by 2012. ‘Regulations’ differ from ‘Directives’ in Brussels terminology in that they enter European law immediately – i.e. without member states having to pass their own national regulation.

As currently drafted, the CPR will require emissions to be tested as part of CE marking. Further, both external assessment (accredited labs, reference methods, etc) and in-house QC testing of emissions will be required to demonstrate compliance.

Which sectors will be affected?
Amendments to European construction product regulations impact a surprising number of trades, for example thermal insulating materials, wood-based products, plaster board, paints and varnishes, adhesives, sealants for joints, flooring materials, structural foam and wall coverings.

Longer term, the requirement to monitor chemical emissions from products and materials is expected to extend way beyond the construction products sectors. REACH was adopted by the European Parliament at the end of 2006 and came into force in June 2007. It implements a uniform legal system for all chemicals inside the EU and European Economic Area and will impact an estimated 80% of manufacturing industry.

Under REACH, chemical manufacturers, importers and downstream users will need to prepare technical dossiers and/or ‘Chemical Safety Reports’ depending on tonnages. If an article or preparation contains one or more potentially hazardous chemicals at levels above 0.1%, which could be emitted under normal conditions of use (intentional or unintentional release), this must be taken into account. It is therefore anticipated that REACH will expand the requirement for chemical emission testing to consumer goods generally. REACH guidance relating to testing emissions of substances from articles and preparations lists many of the methods developed for construction products. [ECHA, 2008] .

What do reference methods for materials emissions testing involve?
Standard reference methods for testing material emissions to indoor air involve placing representative samples of products and materials into test chambers to simulate real world use. The chamber is then connected to a supply of clean air and the air coming out of the chamber is sampled and analysed at various times to see what chemicals are being emitted. The methods are usually broken down into multiple separate sections covering sample collection and preparation, emissions testing and vapour analysis.

The most important ‘horizontal’ reference methods for emissions testing have been developed by CEN and ISO for compliance with the CPD and are now available as parts 6, 9, 10 and 11 of EN/ISO standard 16000. CEN TC351 is in the process of amalgamating and validating these standards under Mandate M/366. Once this work is completed (estimated: 2010/11), chemical emissions testing, per TC351-validated methods, will become a mandatory part of CE marking for construction products – first under the CPD and then under the CPR.

Reference methods are preferred for formal product certification because they generate analytical data that relates most closely to real-world use. However,  it is clear that formal emissions testing methods are lengthy and relatively complex – which translates to relatively ‘expensive’ for manufacturers. The time required (several days, even weeks) also precludes the use of these standard procedures for quality control of production, quick product screening or for convenient testing of prototype materials under development. Thus, while there are few that would contest the use of conventional emissions testing for formal product certification, there is an additional need for complementary rapid and cost-effective emissions screening methodology that could be used by manufacturers and others for routine quality control and product development.

Product approvals and labelling schemes
Before a reference test method can by implemented as part of CE marking, it must be adopted into a product approval protocol. Test protocols specify the test method plus additional requirements such as when it should be carried out, which compounds to target and, most importantly, pass / fail criteria (i.e. limit levels for emissions above which a product would fail the certification process because one or more compounds are being emitted from that product material at an unacceptably high rate).

Key example emission test protocols include the German AgBB scheme, the French AFFSET scheme, the Finnish M1 label and the Californian CHPS programme. There are also many voluntary sector-specific emissions labelling schemes like the GUT carpet label or EMI-Code for adhesives. A schematic of the AgBB approval steps are shown in Figure 3 as an example. The AgBB scheme, AFFSET protocol and CHPS programme include extensive and regularly updated lists of 150 or more target chemicals plus class 1 and 2 carcinogens.

Harmonising the large number of product emission protocols used today is extremely challenging due to the history and vested interests of proponents of each individual label. However, harmonisation is critical to the success of CE marking. It is also an important part of making sure that manufacturers are not required to carry out multiple similar tests on the same products to get the broad approval they need.

There are a number of European and international initiatives currently working on harmonisation of product approval criteria, most notably an EC expert group, under the umbrella of the Joint European Research Centre at Ispra in Italy. By the time the CPR is adopted and standard validation work within CEN TC351 is completed, it is expected that a harmonised product approval process will be available for CE marking and that this will probably follow the general principles of the German AgBB scheme and French AFFSET protocol. It is further expected that relevant product related technical committees within CEN will be heavily involved in setting specific product performance (pass/fail) criteria for their types of product.

Fast emissions screening for factory production control
As mentioned, rigorous, reference methods for testing chemical emissions to indoor air are generally demanding, lengthy (3 to 28 days) and unsuitable for in-house industrial tests. The need for additional secondary (‘initial’ or ‘screening’) methods, to complement formal (certification) emissions test methods, is referenced extensively in EC mandate M/366 itself and has led to several new standards being drafted; for example, ISO WD 12219-3 for car trim components and another within ASTM [ASTM, 2008] . When adopted, the CPR is also expected to drive significant increased demand for quick, secondary emissions screening because it will require both certification of chemical emissions by an accredited third party lab (using reference methods) plus routine factory production control.

Historically, few analytical methods have been developed for screening VOC emissions from construction products. Methods used to date have typically involved either GC(MS) analysis of the ‘volatile’ content of products which are applied as liquids (e.g. EN ISO 11890-2 for measuring the organic content of paint) or direct TD-GCMS analysis of small samples of solid- or liquid-applied products and materials (see Figures 4 and 5). However, it is often difficult to correlate such content test data with results from reference emission methods. Manufacturers of paint or paint additives, for example, can design products that contain solvent, but in which that solvent is encapsulated such that it can never escape to the indoor environment. Content testing is also unsuitable as a guide to emissions from most composite products.

Regulators both sides of the Atlantic are keen to provide manufacturers with a cost-effective and quick screening method that does correlate with standard tests and that can be used to demonstrate conformity with emission limits as part of routine quality control. From industry’s perspective, access to a good reliable screening method would also facilitate in-house checks on batch-to-batch product uniformity / conformity, and allow manufacturers to demonstrate emission profile consistency across a product range (e.g. from different colour versions of the same product). Practical and quick screening methods would also contribute to the development of low emissions products by allowing manufacturers to test new products during development and by enabling them to compare their own materials against recognised ‘best-in-class’ products.

Examples of the new types of emissions screening methods being made available include the draft ASTM standard for screening emissions using micro-scale chambers (ASTM, 2008)  and ISO WD 12219-3 for screening car trim component emissions using micro-chambers. These involve small, heatable chambers that can be used at line and which can carry out tests in 30-40 minutes, rather than several days. Companies such as Markes International are developing commercial micro-scale chamber equipment (Figure 6) that is compatible with the latest emissions screening standards and produces data which correlates with primary reference methods [Schripp et al, 2007 ; PARD ]. Commercial micro-chamber equipment is generally small and portable and is therefore suited for use on the factory floor as well as in field- and laboratory-based applications. It usually accommodates a wide range of solid and liquid materials in multiple (typically 4 or 6) chambers. 

To complement the quick portable test equipment, Markes and its partners are also developing new software tools such as TargetView to deskill interpretation of the complex TD-GCMS emission profiles without compromising data quality. TargetView enhances the processing of TD-GCMS data by automatically detecting and quantifying specific target compounds (Figure 7) from complex emission profiles. The new software aids comparison with control levels (e.g. for individual target compounds or the overall emission profile) thus simplifying rapid and reliable pass/fail assessment.

Manufacturers need to be aware of but not alarmed by the current regulatory developments in the construction products sector and how these changes could impact their business. Methods are being harmonised to eliminate risk of multiple tests being required for certification and minimise similar barriers to trade. Leading specialist analytical technology providers like Markes are also focusing considerable development effort on technical solutions to simplify in-house quality control of product emissions while still maintaining good correlation with reference emissions methods and compliance with regulatory requirements. l

email: enquiries@markes.com

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