wood: PAH (EPA)

Polycyclic aromatic hydrocarbons are a natural component of tar and mineral oil. The so-called tar oils have been used as wood preservatives and sealants. They act against insects and fungi. The group includes several hundred compounds, many of them classified as carcinogenic. In the 1980s the EPA commission (US Environmental Protection Agency) defined 16 substances as key compounds which can be analysed as representative of the whole group.