A photochemically reactive chemical gas, composed ofnon-methane hydrocarbons, that may contribute to the formation ofsmog. Also sometimes referred to asNon-Methane Organic Gases (NMOGs). See also:Volatile Organic CompoundsandHydrocarbons
California Air Resources Board ARB (California Environmental Protection Agency), glossary of air pollution terms, Sacramento, CA, USA 2013. http://www.arb.ca.gov/html/gloss.htm, (Air Pollut - Amer) {594}