‘VOC’ stands for volatile organic compounds. “Organic” means it has at least one carbon atom. “Volatile” means it is a gas under normal atmospheric conditions, so it has low boiling point and a high vapor pressure. That means these chemicals evaporate easily and often react with other substances in the air–they’re volatile. Examples of VOCs include benzene, formaldehyde, and toluene.
VOCs can come from natural sources (such as flowers) or from man-made sources (such as paint and glues). Smells are also often VOCs that our noses register. If you’ve ever opened a dry erase marker and smelled that chemical smell, you’ve smelled VOCs!