What is it?
A simple alcohol, also called isopropanol or rubbing alcohol. It dissolves other ingredients, thins formulas, evaporates quickly and kills germs, so it is used in hair dyes, nail polish and removers, hair tonics, toners, hand sanitizers and disinfecting products. It is a different molecule from the ethanol in alcoholic drinks and is poisonous if swallowed.
Key information
- The CIR Expert Panel concluded that isopropyl alcohol is safe in the present practices of use and concentration.
- IARC places isopropyl alcohol in Group 3, not classifiable as to its carcinogenicity to humans.
- It is poisonous if swallowed, a severe eye irritant and flammable.
- Rubbing alcohol is an approved ingredient in U.S. over-the-counter topical antimicrobial drug products.
More information
Isopropyl alcohol is used in cosmetics mainly as a solvent. FDA data from 2009 listed it in about 1,650 products, most often hair dyes and nail polish, at concentrations from 0.002 percent up to 100 percent in some nail products. Rubbing alcohol is also an approved ingredient in over-the-counter topical antimicrobial drug products.
The Cosmetic Ingredient Review (CIR) Expert Panel concluded that isopropyl alcohol is safe in the present practices of use and concentration (report published in 2012). Formulas containing it did not cause allergic sensitization in human repeat patch tests, and it was not genotoxic. A 70 percent solution was a severe eye irritant in rabbits. It is absorbed through skin, but in one animal study researchers concluded that significant toxicity would need prolonged exposure, such as repeated sponging or soaking for several hours. In long-term inhalation studies at high concentrations, rats developed worse kidney disease and more benign testicular tumors, while mice developed no tumors. IARC classifies isopropyl alcohol in Group 3, not classifiable as to its carcinogenicity to humans.
Swallowing is the real danger. The lowest reported fatal dose in adults is 2 to 4 mL per kilogram of body weight, and about 6 mL per kilogram has caused coma in children. The FDA warns that even a small amount of hand sanitizer can poison a child. For workers, NIOSH lists eye, nose and throat irritation, drowsiness, dizziness, headache and dry, cracking skin, and classes it as a flammable liquid with a flash point of 53°F.
Reality check: in products applied to skin and left to evaporate, isopropyl alcohol is considered low risk for most people, but it is drying, irritating to the eyes and poisonous if swallowed. Keep it away from children, eyes and flames. See also SD Alcohol 40-B.
Sources: Cosmetic Ingredient Review: Final report on methyl acetate, simple alkyl acetate esters, acetic acid and its salts, propyl alcohol and isopropyl alcohol (panel book, 2010); Cosmetic Ingredient Review: Quick reference table of safety conclusions (September 2022); CDC NIOSH Pocket Guide to Chemical Hazards: Isopropyl alcohol; FDA: Safely using hand sanitizer
