Aluminum Starch Octenylsuccinate
Also known as Aluminum starch octenylsuccinate, Starch, hydrogen octenylbutanedioate, aluminum salt, Modified starch aluminum salt
“CIR Expert Panel says: safe as used in cosmetics.”
Aluminum Starch Octenylsuccinate (CAS 9087-61-0) is the aluminum salt of octenylsuccinic acid-modified starch, used as an absorbent, anti-caking agent, and viscosity modifier in cosmetic powders, deodorants, and primers at concentrations up to 30%. The CIR Expert Panel conducted a full safety assessment in 2002 (Nair & Yamarik, IJT 21(S1):1-7, PMID 12042058) covering oral, dermal, ocular, and inhalation toxicity data; no adverse systemic, reproductive, developmental, or sensitization effects were found. The panel determined the ingredient safe as used provided that heavy metal concentration limits applicable to modified food starches are not exceeded. In 2023, the CIR Expert Panel reviewed updated use data and confirmed the ingredient remains acceptable for cosmetic use (Akinsulie et al., IJT 42(3_suppl):12S-13S, PMID 37774506). Consumer concern about systemic aluminum exposure from cosmetics (e.g., antiperspirant/breast cancer hypotheses) is addressed factually by the CIR assessment: the modified starch matrix significantly limits aluminum bioavailability compared to soluble aluminum salts, and the 2002 and 2023 CIR reviews found no evidence of systemic aluminum toxicity from cosmetic use of this ingredient at reported concentrations.
Effective absorbent and anti-caking agent used in face powders, deodorant sticks, pressed powders, and primers to improve texture and reduce caking
Modified starch matrix provides good skin-feel and is derived from a natural polymer base
Inhalation study in rats was negative; minimal dermal irritation and no sensitization found in clinical testing
Consumer concern about systemic aluminum exposure: aluminum salts in cosmetics have been the subject of public debate, particularly regarding antiperspirants. The CIR Expert Panel evaluated this ingredient specifically and found no evidence of systemic aluminum toxicity from cosmetic use; the octenylsuccinate-modified starch matrix limits aluminum bioavailability compared to soluble aluminum salts. The SQ finding (safe as used with heavy metal concentration limits) reflects a precautionary impurity control, not a systemic toxicity concern about aluminum itself.
Heavy metal impurity limits: the SQ condition requires that cosmetic-grade material meet established heavy metal concentration limits (equivalent to those for modified food starches), which controls for arsenic, lead, mercury, and cadmium as process-related impurities.
CIR Quick Reference Table (12/2017, revised 07/2018) — Aluminum Starch Octenylsuccinate row: Finding=SQ, Detail='safe as used provided th…
“Aluminum Starch Octenylsuccinate | SQ | safe as used provided that established limitations imposed on heavy metal concentrations are not exceeded | IJT 21(S1):1-7, 2002”— QRT-122017revised072018.pdf, p. 5