Polycyclic Aromatic Hydrocarbons (PAH)
Polycyclic aromatic hydrocarbons (PAH) represent a large class of naturally occurring hydrocarbons which are generated as by-products during combustion processes. The pure compounds are white or yellowish crystalline solids. They are insoluble in water but dissolve readily in fats and oils. Under EPER the PAHs Benzo(a)pyrene, Benzo(ghi)perylene, Benzo(k)fluoranthene, Fluoranthene, Indeno(1,2,3-cd)pyrene and Benzo(b)fluoranthene are included.
PAHs are not typically manufactured deliberately other than at a laboratory scale for use in research and analysis, but are present incidentally in a wide range of products, such as diesel, creosote, coal tar products, pitch and tar used for roofing and road construction.
Environmental releases of PAHs result from human activity or natural sources such as forest fires. The majority of PAHs are released by incomplete combustion of fossil fuels and wood. Sources in industry are the manufacture of aluminium and coke ovens. Emissions may also occur via evaporation or leaching from PAH containing materials.
Impacts on human health and environment
Certain PAHs are known to cause cancer, birth defects and mutations on prolonged exposure to human and animal tissue.
The ability of some PAHs to travel long distances through the atmosphere, and pose potential concerns to humans and wildlife at locations remote from the emission source led to categorisation of PAHs as Persistent Organic Pollutants, the so-called POPs. PAHs are listed as priority hazardous substances in the Water Framework Directive.
Emission to air reporting threshold: 50 kg/year
Emission to water reporting threshold: 5 kg/year
Data source: European Pollutant Emission Register