Propyl Gallate

Propyl gallate is an antioxidant preservative used at low levels (typically ~0.01–0.1%) but has a documented history of causing contact dermatitis and positive patch-test reactions in a subset of users. While many tolerate it, its sensitization/allergen potential makes it a moderate-risk ingredient for eczema-prone or highly reactive skin, warranting patch testing and cautious use. Safety Notes: Propyl gallate is used as an oil-phase antioxidant to slow rancidity of unsaturated oils, fragrances, and certain actives; in mainstream leave-on and rinse-off cosmetics it is often present at trace-to-low levels (≈0.001–0.05%) consistent with typical antioxidant dosing and finished-product labeling practices. High-strength OTC niche formulations (especially anhydrous/oily products like balms, oil serums, and some specialty creams) have been observed/formulated up to about 0.5% to protect high-oxidation-risk lipid systems, which aligns with common industry upper-use limits for propyl gallate in cosmetics. Usage is primarily in leave-on oil-rich products, but similar low dosing can appear in rinse-off products when lipid/fragrance oxidation protection is needed.