Hydroxyethylcellulose
Also known as HEC, Natrosol, Hydroxyethyl cellulose, Cellulose hydroxyethyl ether
“CIR Expert Panel says: safe as used in cosmetics.”
Hydroxyethylcellulose (HEC, CAS 9004-62-0) is a nonionic, water-soluble cellulose ether produced by reacting cellulose with ethylene oxide, used in cosmetics as a viscosity-increasing agent, film former, and emulsion stabilizer at typical concentrations of 0.1–2%. The CIR Expert Panel originally assessed HEC together with four related cellulose derivatives (Hydroxypropylcellulose, Methylcellulose, Hydroxypropyl Methylcellulose, and Cellulose Gum) in 1986 (JACT 5(3):1-59, 1986) and issued an amended safety assessment in March 2009, concluding that hydroxyethylcellulose is safe as used in cosmetic formulations. The assessment found HEC to be practically nontoxic by oral, dermal, inhalation, and intraperitoneal routes; minimally to non-irritating to skin and eyes; and non-mutagenic. Its high molecular weight (typically 90,000–1,300,000 Daltons depending on grade) prevents significant skin penetration, making systemic exposure negligible at topical use concentrations.
Nonionic water-soluble thickener compatible with anionic, cationic, and nonionic cosmetic systems across a wide pH range
High molecular weight prevents skin penetration; systemic bioavailability is negligible at topical use concentrations
CIR Expert Panel concluded safe as used in cosmetics:1-59, 1986; amended assessment 03/2009)
Long-established cosmetic use with no evidence of sensitization or cumulative toxicity at typical concentrations
CIR Quick Reference Table (12/2017, revised 07/2018) — Hydroxyethylcellulose row: Finding=S, Citation='Amended safety assessment 03/09 - …
“Hydroxyethylcellulose | S | [no detail column entry] | Amended safety assessment 03/09 - Available from CIR JACT 5(3):1-59, 1986 (original report)”— QRT-122017revised072018.pdf, p. 62