Styrene is a volatile colorless liquid, used for polymer production. Petrochemical industry and plastics and resin production are the main air pollution sources.

Impact on human health
Styrene penetrates the human body through inhalation and to a small extent through the skin. It spreads fast in the body and accumulates mainly in the fatty tissue. It causes eye inflammation, disorders of the digestive system and depression. Styrene metabolites are eliminated with the urine.
Irritation of the respiratory tract and the conjunctiva is witnessed in professional exposure to styrene. The effect on the central nervous system is expressed in infirmity, fatigue, headache, dizziness, which is witnessed for styrene concentrations above 200 mg/m3. Prolonged exposure to styrene may lead to EEG (electroencephalogram) disorders.
It is established that the olfactive threshold of styrene is 70 µg/m3.
The data of eventual mutagenous and carcinogenic effect of styrene exposure are limited and unconvincing. The International Agency for Research of Cancer classifies it as a group 3 carcinogenic substance.
The threshold of toxic effect on the population is established based on observation of people exposed to the toxic action of styrene with ensurance of 10-fold safety interval, assuming a concentration of 800 µg/m3 (0.8 mg/m3) for 24-hour exposure.

Our legislation sets the LV for styrene content in the atmospheric air as follows Regulation No. 14 (State Gazette No. 88/1997, amended SG No. 46/1999, amended and supplemented, SG No. 8/2002). -maximum single dose LV (60-minute exposure) - 0,005 mg/m3;
- 24 hour average LV (for 24-hour exposure)- 0,003 mg/m3.