VOC emissions from construction chemicals: measurement, low-emission classes and specification in UK projects

Volatile organic compounds (VOCs) are carbon-based chemicals with an initial boiling point of 250 °C or less under standard atmospheric pressure, as defined by the EU Paints Directive 2004/42/EC. Common examples include formaldehyde, benzene, xylene, and toluene. These substances, widely used in construction chemicals such as paints, varnishes, adhesives, and wood preservatives, pose significant health and environmental risks. Several EU directives and regulations now limit their presence and release from building materials, requiring specifiers and product manufacturers to understand testing methods, emission classes, and compliance pathways.

What are the legal limits for VOC content in construction products?

The EU Paints Directive sets legally binding maximum VOC content levels for paints and varnishes, ranging from 30 g/L for water-based primers and matte interior paints to 850 g/L for preparatory coatings used in vehicle refinishing. Products seeking environmental certification, such as the Nordic Swan Ecolabel, must meet even stricter thresholds. Compliance with both the Paints Directive and Nordic Swan criteria can be evaluated using the standard test method ISO 11890-2, which quantifies VOC content in liquid formulations.

For construction products beyond paints and varnishes, the EU Construction Products Regulation addresses VOC emissions through product-specific limits specified in harmonised standards or European assessment documents. These documents typically include explicit criteria for formaldehyde emissions only, with requirements for additional VOCs often established through national legislation or voluntary classification schemes. Standard test methods include EN 16516, which applies to a wide range of products, and EN 717-1, which is primarily used for wood-based panels such as OSB and MDF.

How do recent REACH restrictions affect formaldehyde emissions?

Formaldehyde was added to Annex XVII of the REACH Regulation as a restricted substance, with new emission limits that took effect on 6 August 2026. As of that date, furniture and wood-based articles must not release formaldehyde in concentrations above 0.062 mg/m³, while other indoor articles face a limit of 0.080 mg/m³. EN 717-1 meets the reference conditions specified in the restriction and can therefore be used directly for compliance testing. Other chamber-based standards, such as EN 16516, can also be applied, but a scientifically valid correlation to results obtained under the reference conditions may be required.

Key emission thresholds for construction materials

Which test methods are used for VOC measurement?

VOC testing is typically performed using gas chromatography techniques, such as GC-MS (gas chromatography–mass spectrometry) and GC-FID (gas chromatography–flame ionisation detection). Standard methods are tailored to specific sample types. ISO 11890-2 is the reference method for determining VOC content in paints and varnishes, measuring the difference between non-volatile and total mass of a sample.

For emission testing of solid construction materials, EN 16516 provides a chamber-based method applicable to a wide range of products, including panels, flooring, and wall coverings. EN 717-1, meanwhile, is the established method for wood-based panels and can be used directly to demonstrate compliance with the REACH formaldehyde restriction. Both methods simulate indoor conditions and measure the concentration of emitted compounds in the air over a defined period.

How do VOC requirements differ in medical devices and consumer products?

In the health technology sector, standard ISO 10993-18 is followed in medical device biocompatibility testing to identify the chemical composition of the device and generate data for estimating associated risks. This chemical characterisation covers a variety of substances that may be released during clinical use, including VOCs. Devices with a breathing gas pathway, such as ventilators, require additional testing to measure VOC, SVOC (semi-volatile organic compound), and VVOC (very volatile organic compound) emissions that the patient may be exposed to through the gas stream. These tests are typically performed in accordance with Part 3 of the ISO 18562 standard.

For toys and consumer products, the Toy Safety Directive specifies migration, emission, and content limits for formaldehyde, with testing conducted in accordance with European standards EN 71-9, EN 71-10, and EN 71-11. The analytical approach depends on the type of product: migration testing is used for polymeric toy materials, and extraction tests for textiles, leather, and paper. Annex XVII of the REACH Regulation also restricts the use of several VOCs in consumer articles and mixtures. Entry 72 sets maximum concentration limits for benzene (5 mg/kg), formaldehyde (75 mg/kg), and several additional volatile compounds in footwear and textiles that come into contact with the skin. Entry 48 restricts toluene in adhesives and spray paints, while entry 5 restricts benzene in most substances and mixtures supplied to consumers, both with a maximum concentration limit of 0.1 % by weight.

What should specifiers consider when selecting low-emission products?

Specifiers selecting construction chemicals should verify that products meet the relevant legal limits for VOC content and emissions, and check for third-party certification such as the Nordic Swan Ecolabel where lower thresholds apply. For wood-based panels and furniture, formaldehyde emission data must be current and demonstrate compliance with the REACH restriction that came into force in August 2026. When comparing products, ask suppliers for test reports issued by accredited laboratories using the appropriate standard methods—ISO 11890-2 for content, EN 16516 or EN 717-1 for emissions. Understanding the distinction between content limits (total VOC in the product) and emission limits (VOC released into indoor air) is essential for accurate specification and risk assessment.