Non-methane volatile organic compounds (NMVOC), NMVOC
A group of chemicals (methane is excluded) that contain the element carbon in their molecular structure - i.e. are 'organic'. They easily vaporise at room temperature and most of them have no colour or smell. NMVOCs include in general the following chemical groups: alcohols, aldehydes, alkanes, aromatics, and ketones and halogenated derivatives of these substances.
Some NMVOCs are used as solvents for industrial processes, paints and varnishes.
NMVOCs are released from the burning of fossil fuels, in particular the burning of petrol in road transport. NMVOCs are often present in solvents, for example in paints and aerosol sprays. Dry cleaning and the production of alcoholic drinks are less significant sources of release. Trees and other plants also produce NMVOC naturally. The smell associated with conifer forests is due to the release of natural NMVOCs from the needles and resin.
Excessive exposure to some chemicals in this diverse group may cause effects on health, depending on the particular chemical. Many NMVOCs are involved in reactions that form ground-level ozone, which can damage crops and many materials as well as have potential effects on human health.