Polycyclic aromatic hydrocarbons (PAH) are a family of chemicals mainly derived from oil and coal but also
as by-products from burning a variety of materials. Therefore the main environmental sources are from coke
production, from petrol and diesel engine exhausts, from grilling meat and burning toast. Some PAH compounds,
such as Benzopyrene are carcinogens, mutagens and reproductive toxins. Very few have direct uses although
naphthalene was widely used at one time as mothballs and several are used as chemical intermediates to
manufacture pigments.
The only restriction today of PAH is from the Marketing and Use Directive (now Annex XVII
of the REACH Regulations) which bans the use of extender oil containing any of eight specified PAH in tyres.
Extender oils can contain PAH, although PAH-free extender oils are also available. Extender oils are used by theelectronics industry so that PAH may occur in electrical equipment although there are no restrictions except where
contact with food occurs (e.g. kitchen equipment). Analysis of a variety of materials has detected PAH in ABS,
polypropylene, paints, coatings and in natural materials such as wood, leather and bristles (brushes).
Soot is sometimes used as a black pigment and can contain PAH.TUV eco-labels now require certification that 16
PAH are below specified limits which is important for some types of products in certain countries. This has increased
interest in PAH and could result in pressure for legislation to further restrict it. REACH may be important here as the
regulation applies to commercial purity materials including any impurities.
In the meantime, the manufacturer of a particular product is the best source of information in respect of
PAH substance content