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CarCareTruth

Butoxypropanol

  • Glycol ether solvents
  • CAS 5131-66-8
  • IUPAC: 1-butoxypropan-2-ol

Butoxypropanol (CAS 5131-66-8) appears in 2 of the 2,122 car-care products CarCareTruth tracks (as of August 2026). It is readily biodegradable.

Causes skin irritation (H315) and eye irritation (H319) — the same irritation classifications as 2-butoxyethanol but with less acute systemic concern. Not classified as harmful by inhalation (no H332) at typical use concentrations. Signal word WARNING when classified. Not Prop 65 listed. Not an asthmagen. Lower toxicity profile than its close chemical relative 2-butoxyethanol (CAS 111-76-2).

Butoxypropanol (1-butoxypropan-2-ol, propylene glycol n-butyl ether) is a propylene glycol ether solvent used in consumer cleaning products as a milder alternative to 2-butoxyethanol. It provides similar solvent power with reduced acute toxicity — it does not carry the H302/H312/H332 (harmful by oral, dermal, or inhalation routes) classifications that 2-butoxyethanol carries at higher concentrations.

Why it matters in fabric cleaners: Mothers uses butoxypropanol alongside 2-butoxyethanol at <5% each in their Carpet & Upholstery Cleaner (05424). At these concentrations and in a water base, neither ingredient drives the product above a mild irritant profile. The combination improves surface wetting and soil removal performance at moderate alkalinity (pH 9.5–10.0) without significant VOC contribution.

Regulatory status

  • Not CA Prop 65 listed
  • Not classified under TSCA as hazardous
  • EU CLP: classified as H315 (Skin Irrit. 2) and H319 (Eye Irrit. 2) at >10% concentration in finished products; at <5% in finished product, may fall below classification thresholds

Health & environment profile

VOC
no
Prop 65 listed
no
Asthmagen
no
EPA Safer Choice
no
Aquatic toxicity
no
Biodegradable
yes
Bioaccumulative
no
Persistent
no
Ozone depleting
no
Microplastic
no
PFAS
no
Env. score
5/5
Purpose: Glycol ether co-solvent in fabric cleaners, all-purpose cleaners, and surface degreasers; improves soil penetration and water miscibility with lower volatility than 2-butoxyethanol

Common questions about Butoxypropanol

What is Butoxypropanol used for in car care?
Glycol ether co-solvent in fabric cleaners, all-purpose cleaners, and surface degreasers; improves soil penetration and water miscibility with lower volatility than 2-butoxyethanol
Is Butoxypropanol a VOC?
No. Butoxypropanol is not classified as a volatile organic compound (VOC).
Is Butoxypropanol on California's Proposition 65 list?
No. Butoxypropanol is not on California's Proposition 65 list.
Is Butoxypropanol biodegradable?
Yes. Butoxypropanol has a confirmed biodegradable profile.

2 products contain this

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.