- volatile essential oils in plants, which arise naturally from the hydrocarbon isoprene, C5H8, CH2=C(CH3)-CH=CH2, when 2 isoprene units join to form the most common dimers called monoterpenes.
- hydrocarbons mostly, C10 H16, but oxygen-containing compounds such as alcohols, aldehydes or ketones (the terpenoids) are also found.
- very fragrant, with an odor threshold in the parts-per-billion (ppb) range (see Table 2 in my report on Terpene odors escaping from cannabis growing).
Terpenes used indoors
- solvent (turpentine, from pine trees, is a mixture of monoterpenes, mainly d-3-carene, pinenes, and limonene)
- varnishes, lacquers
- flooring materials, adhesives
- cleaning products (pine oil disinfectant)
- limonene — the most common, from lemony cleaners
- alpha-pinene — very common, from pine oil cleaners
- beta-pinene — common
- camphene —
- 3-carene —
- eucalyptol — an alcohol, C10 H18 O, in mouthwash
- myrcene — from cannabis growing (also much of limonene and the pinenes)
- linalool — an alcohol, C10 H18 O
- alpha-terpineol — an alcohol, C10 H18 O
- menthol — an alcohol, a decanol, C10 H20 O