TBHQ ●
TL;DR. This ingredient is an antioxidant used to slow rancidity and oxidation in oils, fragrances, and colorants. It helps protect formula odor, color, and active stability, but it is not an antimicrobial preservative.
What does TBHQ do in a cosmetic formula?
This ingredient is an antioxidant used to slow rancidity and oxidation in oils, fragrances, and colorants. It helps protect formula odor, color, and active stability, but it is not an antimicrobial preservative.
Is TBHQ clean?
From a clean-beauty perspective, this is a synthetic phenolic antioxidant with more restricted-list friction than simpler alternatives. Low cosmetic use levels are designed to limit irritation and sensitization, but some retailer and certification programs do not accept it.
Is TBHQ sustainable?
This material is typically made from petrochemical feedstocks, so it is not a renewable-leaning choice. Its end-of-life profile is less favorable than readily biodegradable, bio-based antioxidant systems.
Is TBHQ COSMOS-approved?
It is not generally permitted in COSMOS organic or natural formulations because it sits outside the standard’s preferred allowed ingredient categories. Its Green Chemistry alignment is weak due to non-renewable sourcing and less favorable biodegradability compared with plant-derived antioxidant systems.
How does TBHQ work chemically?
The molecule is a substituted phenolic antioxidant that donates hydrogen atoms to lipid and fragrance radicals, forming resonance-stabilized phenoxy radicals that interrupt autoxidation. It is used at very low levels, commonly around 0.001 to 0.1% in cosmetic oil phases, and can discolor or lose activity under strong oxidation, high pH, or metal-catalyzed conditions.
Last updated 2026-05-13