Formaldehyde emissions: Test conditions for wood-based materials

Even today, harmful formaldehyde from wood-based materials and other products is still offgassing into indoor air. Low-emission products are now more important than ever, as, for energy-conservation reasons, new and renovated buildings are more air-tight now than they used to be. The German Environment Agency (UBA) has achieved, that the test conditions have been adapted to the state of the art.

Formaldehyde and indoor air quality

In June 2014, on the basis of the latest findings, the EU classified formaldehyde as “May cause cancer” (category 1 B pursuant to the ⁠CLP⁠ Regulation). Further information on the assessment of risks to health, occurrence and possible measures can be found on our page dedicated to formaldehyde. Although legal regulations (Hazardous Substances Ordinance/ Prohibition of Chemicals Ordinance) have led to a significant reduction in formaldehyde emissions from wood-based materials in recent decades, wood-based materials produced with urea/formaldehyde glues are still a significant source of emissions of formaldehyde into indoor air. This is due to the fact that their formaldehyde emissions barely decrease over time and they are still frequently used in many places in both house building and interior construction work.

Moreover, new and renovated buildings are, for energy-conservation reasons, more air-tight than houses used to be in the past. For reasons of hygiene, an air exchange rate of 0.5/h is desirable. At this rate, the indoor air will be completely renewed once every 2 hours. Modern buildings usually only achieve such values if they have a ventilation system. In many cases, air exchange rates in modern houses are as low as 0.1 to 0.2 per hour. Manual airing alone does not always lead to sufficient removal of pollutant emissions from building products.

A 2014 study commissioned by the German Environment Agency, which evaluated formaldehyde measurements in more than 2,000 homes of different ages, found that about 4 percent of the houses surveyed, including newer ones, exceeded the formaldehyde guideline value. This result corresponds closely with the result of calculations carried out by the Federal Institute for Risk Assessment (BfR) in 2006 to the effect that here the proportion of German households in which the guideline value is exceeded is likely to be between 5 and 10 percent.

Values for the assessment of formaldehyde exposure in indoor environments

In 2016, the German Committee on Indoor Guide Values [AIR] derived an indoor guideline value for formaldehyde of 100 µg/m³. This value should not be exceeded even for a short period of time, based on a measuring period of half an hour. It is in line with the WHO limit value for formaldehyde from 2000. The limit value for formaldehyde, on which the Prohibition of Chemicals Ordinance is based, is 0.1 ppm (124 µg/m³). This value was introduced by the former German public health office, the Bundesgesundheitsamt, as a formaldehyde guideline back in 1977 and confirmed again in 2006 by the Federal Institute for Risk Assessment.

Since formaldehyde increases the frequency of tumours in the upper respiratory tract only at such concentrations which also have a cytotoxic effect, this effect characterises a “practical” threshold. Any risk in the concentration range of the defined “safe” value and in lower concentrations is extremely low, cannot be distinguished from the background risk and is therefore "practically non-existent", according at least to the previous interpretation of the Federal Institute for Risk Assessment (BfR 2006).

Since February 2015, formaldehyde has also been included in the AgBB evaluation scheme. In Germany, the Committee for Health-related Evaluation of Building Products (AgBB) deals with the question of the extent to which materials and objects installed in a house can affect human health. In the AgBB evaluation scheme, formaldehyde has an LCI value (LCI stands for 'lowest concentration of interest') of 100 µg/m3.

Need for action and UBA response

The key test conditions for the marketability of wood-based materials (“Test methods for wood-based materials”) have remained unchanged for almost 30 years.

In the meantime, both indoor environments and the wood-based materials used in them have changed. With the aim of adapting the test conditions for wood-based materials to the current state of the art as described in the AgBB scheme and the associated test standards, UBA has in recent years joined forces with the Federal Institute for Materials Research and Testing (BAM) to carry out a research project.

The aim of the project was to bring the test conditions into line with current building methods and thus to safely obviate the future risk of exceeding the indoor air guide value for formaldehyde of 0.1 ppm by further developing the requirements governing the use of formaldehyde-emitting products. This required a new test procedure. The research project was supervised by a technical advisory board, which met regularly during the period. To provide all interested parties with sufficient information and give them the opportunity to comment, the progress of the project has been reported on this site since the beginning. In terms of its content, the project has now been completed.

In the experimental part of the project, one of the objects of BAM examinations was how high formaldehyde emissions from wood-based materials can become under realistic conditions. Even though many low-formaldehyde products are now available, there are also products on the market that give rise to higher emissions. A particleboard purchased for the research project demonstrated such a high level of formaldehyde emissions that it was declared not marketable in Germany. A market monitoring procedure has been initiated.

On 22 June 2018, a final event on the aforementioned research project took place in Berlin with the active participation of various stakeholders (e.g. test laboratories, wood-based materials industry, furniture industry). The collected presentation slides are included here on this website among other documents, so that all interested parties can find out more. Based on the research results, the following amendment was considered necessary:

To ensure compliance with the level of protection on which the Prohibition of Chemicals Ordinance is based under the conditions found in today’s buildings, the introduction of the horizontal EU-harmonised DIN EN 16516 as a new test standard (“reference standard”) is essential for formaldehyde emissions from wood-based materials. Tests according to the previous reference standard DIN EN 717-1 will continue to be possible on an equal footing. The results of measurements obtained in accordance with EN 717-1 shall be multiplied by a factor of 2.0. Derived methods, such as the gas analysis method, should also continue to be possible. These amendments should be incorporated into the next version of the “Announcment of Analytical Procedures for Sampling and Investigations for Substances and Groups of Substances listed in the annex to the Prohibition of Chemicals Ordinance” published by the German Ministry of the Environment, Nature Conservation and Nuclear Safety BMU. The competent body in Germany - the working group of the Federal government and the Länder on chemical safety (Bund/Länder-Arbeitsgemeinschaft Chemikaliensicherheit - BLAC) - has now decided on this change. The BMU published the amended table, which also deals with substances other than formaldehyde, in the Federal Gazette in November 2018. The BLAC has placed a link to this publication here.

The new test procedure entered into force on 1 January 2020.

A possible EU-wide restriction on formaldehyde is currently being negotiated under the terms of the ⁠REACH⁠ Regulation. You can find out more about this here.