β-Pinene
- Terpene solvents
- CAS 127-91-3
- IUPAC: (1S,5S)-6,6-Dimethyl-2-methylenebicyclo[3.1.1]heptane
β-Pinene (CAS 127-91-3) appears in 1 of the 1,812 car-care products CarCareTruth tracks (as of June 2026). It is classified as a VOC.
Skin sensitizer (ACGIH lists for dermal sensitization). Like α-pinene, oxidation products are the primary sensitization concern. Inhalation at high concentration causes CNS effects.
β-Pinene is the second most abundant monoterpene in pine resin after α-pinene. It is structurally similar to α-pinene but with an exocyclic double bond, which gives it slightly different oxidation kinetics. In penetrating oils, it contributes to the same low surface tension and wicking behavior as α-pinene.
The chemistry mirrors α-pinene: β-pinene oxidizes on exposure to air to form sensitizing peroxides, and ACGIH lists it for dermal sensitization. Repeated bare-hand contact with aged formulas can produce an allergic skin reaction.
Environmentally, β-pinene is biodegradable, not bioaccumulative (log Kow 4.16), but acutely toxic to aquatic organisms. As with α-pinene, its presence does not move a formula toward "environmentally responsible" — natural origin and biodegradability are partially offset by VOC contribution and aquatic toxicity.
Health & environment profile
- VOC
- yes
- Prop 65 listed
- no
- Asthmagen
- no
- EPA Safer Choice
- no
- Aquatic toxicity
- yes
- Biodegradable
- yes
- Bioaccumulative
- no
- Persistent
- no
- Ozone depleting
- no
- Microplastic
- no
- PFAS
- no
- Env. score
- 4/5
Common questions about β-Pinene
- What is β-Pinene used for in car care?
- Bicyclic monoterpene — natural penetrating co-solvent and pine-oil constituent
- Is β-Pinene a VOC?
- Yes. β-Pinene is classified as a volatile organic compound (VOC).
- Is β-Pinene on California's Proposition 65 list?
- No. β-Pinene is not on California's Proposition 65 list.
- Is β-Pinene biodegradable?
- Yes. β-Pinene has a confirmed biodegradable profile.
1 product contain this
CRC Knock'er Loose Penetrating SolventProp 65penetrating-oil
Related
Health and environment notes translate the manufacturer Safety Data Sheet, the GHS classification, and authoritative regulatory listings (California Prop 65, EPA). Not medical advice. They describe the ingredient itself; whether a hazard applies to a finished product depends on its concentration and how it's used.