Car exhaust is a major source of VOCs. Click on image for full size (52 Kb JPEG) Image courtesy UCAR

Volatile Organic Compounds or VOCs are organic chemicals that form a gas at room temperature. They are called organic because they contain the element carbon.. There are many types of VOCs. Hydrocarbons have both hydrogen and carbon atoms and include benzene and toluene. Oxygenates contain carbon, hydrogen and oxygen and come from car exhaust and atmospheric chemical reactions.

Gasoline and natural gas are a major source of VOCs. VOCs are given off by many types of products including: paints and lacquers, paint strippers, cleaning supplies, pesticides, building materials and furnishings, office equipment, and craft materials like glue and markers. All of these things can release VOCs while you are using them and when they are stored.

Some VOCs are quite dangerous, like benzene, polycyclic aromatic hydrocarbons (PAHs) and butadiene. Benzene may increase your chances of getting leukemia. PAHs can cause cancer. Butadiene is found in gasoline engine exhaust and cigarette smoke, and can cause cancer too.

In addition to the health problems that VOCs can cause, VOCs in the air can react with ultraviolet light and nitrogen oxides to form tropospheric ozone.