volatile organic compound (VOC)

is any organic compound that reacts with nitrogen oxides in the presence of sunlight to form ozone, a major component of photochemical smog. VOCs are released from both natural and man-made sources (e.g., trees, automobiles). Automobile VOC emissions can be reduced by lowering gasoline vapor pressure, improving combustion efficiency, and using catalytic converters to trap exhaust emissions.

Also see emissions (automotive).

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