Polycyclic Aromatic Hydrocarbons (PAHs) are series of hydrocarbons contained two or more cyclic aromatics in molecular structure, such as Naphthalene, Anthracene, and Phenanthrene, which have about 150 compounds, and may lead to cancer. Benzo[a]pyrene is first founded PAH which can lead to cancer and usually represent all PAHs.

PAHs are widely contained in petroleum, plastics, rubber, lubricants, crud oil, drugs, dyes, pesticides, capacitor electrolytes, and organic chemicals when not absolutely combustion. PAHs usually can be found in footwear or related materials along with the use of additives or auxiliary chemicals in production.

PAH’s, which are known for their carcinogenic, mutagenic and teratogenic properties, can be found in leather, rubber, plastics, lubricants, paints and other products. As a result of this, EU REACH Annex XVII has placed a restriction on the use of 8 PAH’s in certain products and concentration limits have been applied. Furthermore, the US EPA has restricted the use of a total of 18 PAH’s in consumer goods.