BHA
CAS 25013-16-5 EC 246-563-8
Tert-butyl-4-methoxyphenol
Limited Data
Insufficient safety data available. Consider enriching this ingredient.
Details
Description
Tert-butyl-4-methoxyphenol
Purpose
Function
Antioxidant; synthetic chain-breaking free radical scavenger (SET/HAT mechanism); product preservative against oxidative degradation in oils and waxes
Profile
Properties
Silicone
Silicone free
Compliance
Regulatory Status
EU
Restricted
Safety
GOOD
US
Permitted
EU Max Concentration0.07%
Absorptionmoderate
Sensitizationlow
MoSadequate
NOAEL100 mg/kg
ConcernModerate
Flags
endocrine-concernsccs-assessedprop-65antioxidantsyntheticeu-restriction-pendingedc-flaggedoral-excludedendocrine_disruptorprop65ifra_fragrancefda_food_additive
Verdict
SCCS/1682/25 (Oct 30, 2025, preliminary): safe at ≤0.07% in leave-on and rinse-off products with margin of safety 610–17,251, all exceeding threshold of 100. Weak anti-estrogenic/anti-androgenic signals in vitro/in vivo at high doses; EDC concern flagged. Excluded from oral care and inhalation products. California Prop 65 listed carcinogen.
US Note
FDA: GRAS for food use (21 CFR 172.110). No specific cosmetic concentration limit under 21 CFR; manufacturer safety assessment responsibility. CIR Final Amended Report (Sep 2024): under review. California Prop 65 listed carcinogen (NSRL 4000 µg/day) — warning required for intentional exposure products in CA if threshold exceeded.
Assessment
Ratings
Reference