Potassium sorbate: preservative or controversial?
Arin Editorial · how this is made
You might see potassium sorbate on the ingredient list of a cream or shampoo. It is a preservative that keeps the product from spoiling. It also appears in food, despite the chemical-sounding name.
What it is
Potassium sorbate is the potassium salt of sorbic acid. It is a white crystalline powder, soluble in water. It suppresses the growth of mold, yeast, and some bacteria.
Where it shows up
As a food preservative it is labeled E202. Typical use levels in food are 0.025%-0.1%. In cosmetics it is found in creams, lotions, shampoos, and makeup. Sorbic acid has been used at up to 1% in cosmetics, and potassium sorbate does the same job.
What safety data says
An older CIR review found sorbic acid and potassium sorbate practically non-toxic in acute oral studies and saw no serious effects with up to 10% in the diet. Long-term studies found no cancer or birth defects. Current databases list skin sensitization (SkinSens1) and eye irritation (Category 2A/2). Genetic toxicity tests are mixed, with some positive and some negative results.
Why it is discussed
A French cohort study of 105,260 people linked high potassium sorbate consumption to a 14% increase in overall cancer risk and a 26% increase in breast cancer risk. This is one observational study; it does not prove causation. EFSA is reviewing the temporary acceptable daily intake after a new reproductive toxicity study.
It is currently approved as E202 in food and as a preservative in cosmetics in the EU; EFSA is reassessing the temporary acceptable daily intake.
If you have sensitive skin, potassium sorbate can occasionally cause an allergic reaction. Stop using the product if you see irritation. For food, seeing E202 on a label is not a reason to panic; it is an approved preservative. The cancer link currently rests on a single observational study.
Sources
- CIR (Cosmetic Ingredient Review) Ingredient Status Report
- Journal of the American College of Toxicology, 1988 (via OUCI)
- SpecialChem - Potassium Sorbate
- Cosmetics & Toiletries - Ingredient Profile: Sorbic Acid & Potassium Sorbate
- EFSA Opinion on sorbic acid and potassium sorbate (via EPMC)
- EPA ToxValDB