volatile organic compounds (VOCs)
Organic compounds that evaporate readily, many smelling strongly. Some plants produce large quantities of VOCs, especially isoprene and terpenes (including the essential oils), which can affect air quality in urban situations. In hot sunshine VOCs contribute to the formation of ozone and photochemical smog near ground level.
This definition is abridged from A – Z of tree terms: A companion to British arboriculture.
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