A compound very slightly soluble in water and volatile. 
90% of the benzene in the ambient air comes from road traffic. 
The remaining 10% comes from the evaporation of the fuel storage and distribution.

Health effects 
Carcinogenic, a Class A1 toxicity, known as carcinogenic to humans. Harmful effects on the central nervous system.

Reference method for measurement of benzene is that stipulated in SR EN 14662 Ambient air quality. Standardized method for measuring the concentration of benzene Parts 1, 2 and 3.