Skip to content
CarCareTruth

Isobutane

  • Aliphatic solvents
  • CAS 75-28-5
  • IUPAC: 2-Methylpropane

Isobutane (CAS 75-28-5) appears in 12 of the 2,122 car-care products CarCareTruth tracks (as of August 2026). It is readily biodegradable.

Simple asphyxiant and extremely flammable gas (H220). No specific organ toxicity. Risk profile is fire and explosion only — keep aerosols containing isobutane away from heat and ignition sources.

Isobutane (2-methylpropane) is a four-carbon branched alkane gas used as an aerosol propellant alongside propane and n-butane. It is interchangeable with butane in most formulations and shares the same H220 (extremely flammable gas) + H280 (gas under pressure) classification — fire hazard only, no inhalation toxicity beyond simple asphyxiation at very high concentrations.

Not on Prop 65, not an asthmagen, not a sensitizer, not aquatic-toxic. Disperses as a gas immediately on release. The danger profile is identical to propane and butane — fire and explosion, not chronic toxicity. EPA and CARB classify isobutane as VOC-exempt for aerosol propellant use.

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
4/5
Purpose: Aerosol propellant — branched four-carbon alkane gas used alongside propane and n-butane to pressurize aerosol cans

Common questions about Isobutane

What is Isobutane used for in car care?
Aerosol propellant — branched four-carbon alkane gas used alongside propane and n-butane to pressurize aerosol cans
Is Isobutane a VOC?
No. Isobutane is not classified as a volatile organic compound (VOC).
Is Isobutane on California's Proposition 65 list?
No. Isobutane is not on California's Proposition 65 list.
Is Isobutane biodegradable?
Yes. Isobutane has a confirmed biodegradable profile.

12 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.