Ammonium Persulfate

High-hazard oxidizing agent with well-documented sensitization and respiratory risks. CIR (2022) concluded safe only in brief-contact rinse-off hair colorants and lighteners; data insufficient for leave-on or dentifrice use. Leading cause of occupational asthma in hairdressers with strongly established skin and respiratory sensitization. EU permits use in hair products without specific concentration cap, but professional and consumer exposure controls are advisable. Not appropriate for leave-on formulations or sensitive/compromised skin.

Not prohibited or specifically restricted by FDA for cosmetic use; 157 ingredient uses reported to FDA VCRP, 151 of which are in hair coloring/lightening products. CIR Expert Panel (2022 Amended Assessment, Int. J. Toxicol.) concluded safe as used as oxidizing agent in rinse-off hair colorants and lighteners; data insufficient to conclude safety in leave-on products and dentifrices.