Formaldehyde

Formaldehyde is a substance that has been used industrially for a long time and was originally mainly used to preserve products (used as a preservative). Later, it was increasingly used as a binding agent and adhesive component in wood-based materials, for example for furniture, interior fittings and prefabricated houses. According to the CLP Regulation, the following hazard and safety information applies to formaldehyde: toxic if swallowed, toxic in contact with skin, causes severe skin burns and eye damage, toxic if inhaled, suspected of causing genetic defects and may cause an allergic skin reaction. Since June 2014, formaldehyde has been categorised by the EU as ‘may cause cancer’ (category 1B) based on new findings.

Substances are classified as carcinogenic if they can cause cancer or increase the incidence of cancer. According to the CLP Regulation, carcinogenic substances are classified as follows: Category 1A (substances known to be carcinogenic to humans), Category 1B (substances likely to be carcinogenic to humans) and Category 2 (substances suspected of being carcinogenic to humans). Classification in Category 2 occurs when animal or human data are not sufficiently convincing to justify classification in Category 1(B). Classification in Category 1B occurs when, based on animal data and human experience, it can be assumed that a substance can cause cancer in humans. This may result in restrictions on use of the specific substance.

Rats repeatedly exposed to high concentrations of formaldehyde by inhalation developed tumours in the nasal cavity over the course of their lives. Some scientific studies that have investigated the effects of high formaldehyde exposure at the workplace have found more cases of cancer in the nasal cavity and nasopharynx in the exposed individuals over the course of their lives than was expected (without formaldehyde). However, other studies on workers were unable to confirm these findings. Therefore, it was not classified in the highest category 1A.

The effect of formaldehyde on human health has been assessed by many national and international bodies on the basis of extensive scientific data. According to this, the interaction of several factors is necessary for a carcinogenic effect. Animal studies have shown that tumours in the nasal cavity only occur when the concentration is high enough to cause mucosal damage and an increased rate of cell division. The aforementioned, ultimately carcinogenic effects are therefore generally not to be expected below a certain formaldehyde concentration.

In addition to the aforementioned effect on the mucous membranes when inhaled, higher concentrations of formaldehyde in indoor air can have an irritating effect on the eyes. A reliable link between inhaled formaldehyde and the development or worsening of asthma cannot be confirmed on the basis of the epidemiological studies available to date.

There are a large number of products that contain formaldehyde and can release it into the indoor air. Despite continuous improvement of products in recent decades, wood-based materials, floor coverings, furniture and certain insulating materials (e.g. urea formaldehyde in-situ foams [UF in-situ foams]) continue to be the main sources of formaldehyde. Tobacco smoke contains comparatively large amounts of formaldehyde and even burning candles can be a source of formaldehyde. Formaldehyde can also be found in disinfectants, cosmetics and textiles.

In order to protect the health of the general population, defined formaldehyde concentrations in indoor air should not be exceeded.

The German Committee on Indoor Air Guide Values (AIR), consisting of experts from the federal government and the federal states in Germany, develops guide values for the health assessment of indoor air. A guideline value of 100 µg/m³ has been in place for formaldehyde since 2016. This value should not be exceeded even for short periods (30 minutes) and also corresponds to the recommendation of the World Health Organisation (WHO).

The German Committee for Health-related Evaluation of Building Products (AgBB) has been active for many years in defining and regularly updating limits for emissions of substances (including formaldehyde) in building products to indoor air. The Deutsche Institut für Bautechnik (DIBt) implements these assessment principles for indoor-relevant building products in the approval procedure.

In Germany, the Chemicals Prohibition Ordinance currently stipulates that coated and uncoated wood-based materials (chipboards, core boards, multiply plywood and fibreboards) must be tested before being placed on the market. The steady-state concentration of formaldehyde in the air of a test room caused by the wood-based material should not exceed 0.1 ml/m³ (equivalent to 0.1 ppm or 124 µg/m³). The Chemicals Prohibition Ordinance also stipulates that detergents, cleaning and care products with a mass content of more than 0.2% formaldehyde may not be placed on the market (exception: industrial cleaners). For further details, see the Chemicals Prohibition Ordinance (in German).

Since 2020, a new test method for wood-based materials containing formaldehyde has been used in Germany, with which the test conditions have been adapted to today's structural features and real loading rates.

A new EU-wide ‘Formaldehyde Regulation’ was recently published. This new regulation is a major step forward: As of 6 August 2026, there will be a EU-wide regulation for formaldehyde emissions from wood-based materials and other products for the first time. For the interior fittings of road vehicles, the regulation will not come into force until 6 August 2027. The new regulation sets the following limit values:

• 0.062 mg/m³ for wood-based articles and furniture and the interior fittings of road vehicles
• 0.080 mg/m³ for other articles

As a supplement to the regulation, there will be a European guidance document that describes the required test conditions in detail.

The national regulations in the Chemicals Prohibition Ordinance on the marketability of wood-based materials and furniture containing them will become obsolete when the EU Regulation comes into force.

We recommend using products labelled with the Blue Angel. These are particularly low in emissions and pose significantly lower risks to health and the environment than comparable products. The award criteria for products labelled with the Blue Angel can be viewed on the Blue Angel website.

For products that are not labelled with the Blue Angel, we recommend that, in case of doubt, users ask the manufacturers for evidence and information on the safety of the products. In some cases, the relevant information (test certificates) is already provided on the packaging.

In addition to choosing low-emission products and materials, regular ventilation and damp wiping of surfaces in residential buildings and office workplaces can generally ensure healthier indoor air. This also applies to the reduction of possible indoor air pollution with formaldehyde.