Aluminum Sesquichlorohydrate

Well-established antiperspirant active with decades of safe use in OTC drug products. FDA regulates as a recognized safe and effective antiperspirant active up to 25%. EU SCCS concluded safe at concentration limits defined by product category (non-spray ≤6.25% Al, spray ≤10.60% Al). Dermal absorption is negligibly low (<0.01%) based on robust 26Al tracer human studies — systemic exposure does not meaningfully add to background aluminium burden. No causal link to breast cancer or Alzheimer's disease established in epidemiological literature. Pending EU Annex III formal codification via Omnibus Act 2 (expected Q1 2026). Use within SCCS-recommended concentration windows poses negligible systemic risk.

Regulated as an OTC antiperspirant active ingredient under FDA Monograph M019 (21 CFR 350); permitted up to 25% in antiperspirant formulations; CIR deferred full safety assessment to FDA given OTC drug classification; not prohibited or restricted for cosmetic-only use