Isobutane
AKA “2-Methylpropane, 75-28-5, Trimethylmethane, 1, 1-Dimethylethane, iso-butane, R 600a, Caswell No. 503A, R-600a, HSDB 608”
Ingredient
Ingredient Facts
Isobutane
AKA: 2-Methylpropane, 75-28-5, Trimethylmethane, 1, 1-Dimethylethane, Iso-butane, R 600a, Caswell No. 503A, R-600a, HSDB 608
Ingredient · Propellant · EWG: 7
Synthetic
Not Clean
Isobutane, less than 0.1% w/w butadiene
Solubility Slight (NIOSH, 2024)
Formula
C4H10
Mol. Weight
58.12
CAS #
75-28-5
Form
Liquid
State
Isobutane is a colorless gas with a faint petroleum-like odor. It is shipped as a liquefied gas under its vapor pressure. Contact with the liquid can cause frostbite. It is easily ignited. The vapors
See origin →
Functions
Propellant
Dispenses Product
Locks In Moisture
Propels product from container
Traditional Use
A hydrocarbon gas synthesized from petroleum in the 20th century. Adopted by the cosmetics industry as a propellant in aerosol sprays and foams, replacing earlier flammable propellants.
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Yes
Final Report of the Safety Assessment of Isobutane, Isopentane, n-Butane, and Propane
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Isobutane, Butane, Isopentane and Propane
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Isobutane
European Commission
EU Cosmetic Ingredient Database (CosIng)
Isobutane
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Isobutane
Health Canada
Health Canada Cosmetic Ingredient Hotlist
Isobutane, Isopentane, Butane, and Propane.
Tucker R, Bergfeld WF, Belsito DV, Cohen DE, Klaassen CD et al.
International journal of toxicology, 2025
Isobutane, Isopentane, Butane, and Propane.
Tucker R, Bergfeld WF, Belsito DV, Cohen DE, Klaassen CD et al.
International journal of toxicology, 2025
Isobutane, Isopentane, Butane, and Propane.
Tucker R, Bergfeld WF, Belsito DV, Cohen DE, Klaassen CD et al.
International journal of toxicology, 2025
Verified Jun 2026 · 🧪 = conflict
Data: PubChem · CosIng · EWG · CIR