4-Hexylresorcinol
The short version
A phenolic antioxidant used to prevent shrimp blackspot — a clean-label alternative to sulfites.
It's widely considered safe at the amounts used in food, so we mark it green. The Safety section below has the details.
Where it comes from
Manufactured by alkylation of resorcinol with 1-hexene. Originally introduced as an oral anthelmintic and a throat-lozenge antiseptic; food use developed in the 1990s as a sulfite-free shrimp-preservation chemistry.
How it's used
Dipped onto shrimp, lobster, and crab to prevent the dark melanosis spots (blackspot) caused by polyphenol oxidase activity. Maximum residue 1 mg/kg. A clean-label alternative to sodium metabisulfite for sulfite-sensitive consumers. Also used to prevent enzymatic browning in lychee and cut apples.
Safety profile
ADI of 0–0.45 mg/kg body weight (JECFA). Considered safe at use levels. Far less allergenic than the sulfite-based blackspot inhibitors it replaces.
Physical & chemical properties
White to off-white crystalline solid. Sparingly soluble in water; soluble in ethanol and warm oils.
Regulation worldwide
Permitted in the EU, US (FDA-approved), and most jurisdictions for crustacean and fruit applications.
Educational information only. Not medical or dietary advice.