
Formulator’s Queries, We Answered
1. What is Potassium Persulfate? What is its CAS number and INCI name?
CAS Number: 7727-21-1
INCI Name: Potassium Persulfate
Chemical Identity: The chemical formula is K₂S₂O₈ (also referred to as dipotassium peroxodisulfate).
2. What is the primary function of Potassium Persulfate in cosmetics / personal care?
It acts as a strong oxidizing agent.
It is commonly used in hair-bleaching and hair-lightening formulations, to help decolorize natural hair pigment so that hair can be lightened or dyed.
In addition to hair applications, it can be used in nail-care (e.g. in some nail products), or in polymerization/oxidation-related processes relevant to cosmetic raw-material manufacture
3. Is Potassium Persulfate safe for use in cosmetics? Under what conditions?
According to a safety assessment by the expert panel reviewing persulfates in cosmetics, Potassium Persulfate (along with other persulfates) is considered safe when used as oxidizing agents in hair colorants and hair-lighteners, for brief/discontinuous use followed by thorough rinsing (i.e. rinse-off products) — but data are insufficient to conclude safety for leave-on products or dentifrices.
4. What are the hazards and risks associated with Potassium Persulfate?
Skin and eye irritation / corrosion: Direct contact may cause irritation or burns.
Respiratory sensitization / irritation: Inhalation of dust or aerosol may provoke respiratory issues, especially for sensitized individuals.
Allergic sensitization: Repeated or prolonged exposure may lead to sensitization (i.e. allergic reactions) upon subsequent use
5. In what types of cosmetic / personal-care products is Potassium Persulfate typically used?
Hair bleaches / hair lighteners / hair colorants — most common application.
Nail care / nail-treatment products — for polymerization or hardening processes (e.g. acrylic nails) in some nail systems.
Raw-material processing / polymerization in cosmetic ingredient supply chain — e.g. as oxidizing agent or initiator during synthesis of polymers, resins, acrylates, etc. that may be used in various beauty formulations.