Avobenzone vs Sorbic Acid: which is worse?

What is Avobenzone?

Avobenzone (INCI: Butyl Methoxydibenzoylmethane) is a chemical UV filter that is the only FDA-approved broad-spectrum UVA-absorbing active sunscreen ingredient in the US that covers the full UVA spectrum (320–400 nm). It is inherently photounstable and must be combined with photostabilizers.

What is Sorbic Acid?

Sorbic acid is an unsaturated fatty acid naturally occurring in the berries of the rowan tree (Sorbus aucuparia). Commercially, it is produced synthetically and used as a broad-spectrum antimicrobial preservative, effective primarily against molds and yeasts, and to a lesser extent bacteria, at acidic to neutral pH.

Documented risks

Avobenzone: Avobenzone is effective and considered safe at approved concentrations (up to 3% in US OTC sunscreens). A 2019 FDA study found that several sunscreen actives including avobenzone were systemically absorbed above the 0.5 ng/mL threshold after repeated use, triggering a call for additional safety data. This does not indicate harm, but the FDA requested more studies under its proposed sunscreen monograph. Current evidence supports its continued safe use. No clear endocrine disruption or carcinogenicity at human exposure levels is established.

Sorbic Acid: One of the safest preservatives in use. Sorbic acid is metabolized normally as a short-chain fatty acid and poses no identified carcinogenic, mutagenic, or reproductive risks. The ADI (Acceptable Daily Intake) is 25 mg/kg body weight/day, and typical dietary exposure is well below this threshold. Rare skin sensitization has been reported in cosmetic contexts but is not relevant to food consumption. EFSA and FDA both classify it as safe.