Polycyclic Aromatic Hydrocarbons (PAH) are unsubstituted organic compounds that consist of fused aromatic rings. As with all hydrocarbons, they do not contain heteroatoms.
Naphthalene and phenanthrene are widespread examples. PAHs occur in fossil fuel deposits, such as tar or oil and are produced as byproducts of processing such fuels, in the drilling of oil or gas wells or their combustion. Garbage, which frequently contains plastic material, on incineration, can also emit polycyclic aromatic hydrocarbons.
They can also be produced naturally in forest fires. These compounds can seriously pollute the atmosphere and water resources such as aquifers, rivers and the sea, especially concentrating in the sediment.The danger, as environmental pollutants, is that they are serious short and long-term health hazards, some of them being carcinogenic, mutagenic, and teratogenic.
These compounds tend to be very persistent in the environment, having a very slow rate of biodegradation and so modern standards seek to control their release. The IMI analytical laboratories are equipped to perform PAH analyses in accordance to accepted international standards.