For sampling formaldehyde and other aldehydes the following sampling systems are available at the GSA:
- SG350ex with a DNPH-coated silica gel tube (personal and stationary sampling).
- SG5100ex with DNPH cartridge (personal and stationary sampling).
For personal and stationary sampling, the substances in the air are sucked in with a battery-operated and volume flow-controlled pump (SG350ex or SG5100ex) with a volume flow of 0.333 l/ min or 1 l/ min, respectively. We recommend a measurement duration of 2 h to achieve a volume of 39.6 L or 120 L, respectively, in order to be able to verify the guide value (RWI) and guideline value (long-term).
A DNPH-coated silica gel tube or DNPH-coated filter is used as adsorption medium. For this purpose, the tube or filter holder is opened immediately before sampling, then sampled and closed again after sampling.
The analytical determination is carried out by means of HPLC (high performance liquid chromatography) and UV detection (photo diode array detector).
According to EU Regulation 605/2014, formaldehyde is classified as carcinogenic in category 1B (carc. 1B) and mutagenic category 2 (muta. 2). However, there is no fixed, binding limit value for formaldehyde for indoor spaces.
At the national level, the Committee for Indoor Air Quality Control (AIR), set up by the federal states and the Federal Environment Agency, develops recommendations for maximum values for substances in indoor spaces. For formaldehyde, there has been a guide value RWI of 0.1 mg/m3 since 2016. A guide value II (RWII) was not specified.
In order to avoid health hazards in the case of long-term exposure, the World Health Organization (WHO) recommends a guideline value (long-term) of 0.063 mg/m³. This is a so-called NOAEC (= no observed adverse effect concentration), which corresponds to the highest dose (exposure concentration) at which no toxic findings are observed. For short-term exposure (up to 30 minutes), the WHO recommends 0.1 mg/m³.