The generic term for easily volatile liquid or vapor organic compounds in the atmosphere, if produces combustion sub stances into noxious smog such as ozone.

As it is generated mostly from artificial sources like painting, coating facilities, gas stations and various vehicle emission, global warming by these surely can be so fatal to our environment and human body that most countries are endeavoring to regulate exhaust, emission.

In particular, volatile organic compounds give rise to ozone.
Benzene among VOC can cause carcinogenesis, the central verve trouble, chromosomal abnormalities and photochemistry smog by chlorinated hydrocarbons does harm to eyes, close visibility, asthma, animals, plant and crops.