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Methyl Isobutyl Ketone

  • Other solvents
  • CAS 108-10-1
  • IUPAC: 4-methylpentan-2-one

Methyl Isobutyl Ketone (CAS 108-10-1) appears in 4 of the 1,812 car-care products CarCareTruth tracks (as of June 2026). It is classified as a VOC.

H336 (drowsiness/dizziness — narcotic effects) at mixture level. OSHA PEL 100 ppm; ACGIH TLV 20 ppm (due to limited reproductive toxicity data). Not classified as carcinogen or Prop 65 listed. H335 (respiratory irritation) possible in high-vapor environments. LD50 oral rat ~2080 mg/kg — low acute oral toxicity. Primary concern is CNS depression at high inhalation concentrations.

Methyl isobutyl ketone (MIBK) is a medium-evaporation ketone solvent used in lacquers, printing inks, and surface coatings as a co-solvent for cellulose nitrate and acrylic resin systems. Its solvency and evaporation rate make it a useful modifier in automotive touch-up paints alongside faster-evaporating solvents like MEK. ACGIH lowered its TLV from 50 ppm to 20 ppm in consideration of limited reproductive toxicity data in animal studies; the Prop 65 status has not been triggered as of 2026.

Health & environment profile

VOC
yes
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: Ketone co-solvent in lacquers, touch-up paints, and coatings; moderate evaporation rate, high solvency for cellulose nitrate and acrylic resins

Common questions about Methyl Isobutyl Ketone

What is Methyl Isobutyl Ketone used for in car care?
Ketone co-solvent in lacquers, touch-up paints, and coatings; moderate evaporation rate, high solvency for cellulose nitrate and acrylic resins
Is Methyl Isobutyl Ketone a VOC?
Yes. Methyl Isobutyl Ketone is classified as a volatile organic compound (VOC).
Is Methyl Isobutyl Ketone on California's Proposition 65 list?
No. Methyl Isobutyl Ketone is not on California's Proposition 65 list.
Is Methyl Isobutyl Ketone biodegradable?
Yes. Methyl Isobutyl Ketone has a confirmed biodegradable profile.

4 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.