VOCs, or volatile organic compounds, are compounds that contain carbon atoms and that, at room temperature, easily evaporate. Too small to see and virtually omnipresent both indoors and out, they can be inhaled in normal breathing.
“Volatile” means that the compound vaporizes. “Organic” in this context means “containing carbon molecules.” While “organic” also usually suggests “naturally occurring,” many VOCs are human-made.
Some VOCs—like the smells emitted by many decorative flowers—are pleasant when inhaled. However, not all VOCs have an associated smell, which means that people cannot always tell that they are breathing them. This is a problem because, while many VOCs are harmless, many are hazardous.
Microbial Volatile Organic Compounds
Microbial volatile organic compounds (mVOCs) are especially small. They include mold as well as other fungi and some bacteria.
Some mVOCs are often blamed as the cause of “sick house syndrome” and “sick building syndrome.” Health care professionals sometimes use these terms when referring to people with a mix of adverse responses to the structures in which they live or work. Dampness as well as naturally occurring mVOCs like mold and human-made VOCs in construction materials can all play a role in sick house/building syndrome.
Even though it is not technically an mVOC, the radioactive gas radon is often categorized in public documents with mVOCs because it’s invisible when inhaled and can dangerously contaminate homes and other structures. Produced by the breakdown of uranium in the soil, rock, and water under a building, radon is the leading cause of lung cancer among non-smokers, according to the Environmental Protection Agency (EPA).