Material emissions – Formaldehyde monitoring
Building materials and household products
Formaldehyde (HCHO) is used worldwide in the manufacture of building materials and household products, and is also a by-product of combustion. As a result, it is one of the most abundant toxic pollutants in indoor air.
With this mind, guidelines for indoor air quality (IAQ) and vehicle interior air quality (VIAQ) now state that the concentration of formaldehyde should not exceed certain limits. To meet these requirements, manufacturers of furnishings, building materials and car trim components are now expected to produce goods with low formaldehyde emissions.
Formaldehyde emission regulations and protocols cover a variety of areas, with the following being of particular importance:
Two more general methods for the detection of volatile and semi-volatile organic compounds (VOCs and SVOCs) also cover formaldehyde:
What Markes can offer
Although formaldehyde is not compatible with thermal desorption anlysis, Markes’ sampling technologies can still be used. In particular, the Micro-Chamber/Thermal Extractor can successfully be applied to the collection of formaldehyde vapours released from products or materials.
The sample is placed in one of the compact chambers, which is held at a specified temperature as a flow of gas is applied. However, instead of being swept onto a TD sample tube, the gas flow is either:
- Collected onto a cartridge containing 2,4-dinitrophenylhydrazine (DNPH), which reacts with the formaldehyde to generate a stable derivative. The cartridge is then analysed by high-performance liquid chromatography (HPLC).
- Passed directly into an on-line formaldehyde monitor, such as the AL4021 from Aero-Laser GmbH. In this case, the formaldehyde reacts with acetylacetone, producing a fluorescent derivative that can be detected spectroscopically.