Zinc Pyrithione (ZPT)CAS 13463-41-7
Anti-dandruff active ingredient also used in exterior paint, deck stains, and antimicrobial shower curtains.
Toxic Chemical Databases
Substance-specific listings — these flags are for Zinc Pyrithione alone, not for the broader family.
Chemical Type
Heavy-Metal Pyridine Biocide
Chemical Description
ZPT is best known as the active ingredient in anti-dandruff shampoo, but in building materials it is a major commercial biocide for exterior paint, marine antifoulants, deck stains, and antimicrobial textile and shower-curtain treatments. EU REACH classified ZPT as a Category 1B reproductive toxicant in 2020 based on developmental-toxicity findings in rodent studies. Aquatic toxicity is severe — ZPT was a co-named culprit in marine sediment contamination near boat-storage facilities. Persistent on exterior surfaces; bioaccumulates in marine sediments.
Biological Activity
Severity scores specific to this substance, NOT the parent family average. Differences between siblings are real and meaningful.
Top Health Consequences
- REACH Category 1B reproductive toxicant
- Developmental toxicity in animal studies
- Severe aquatic toxicity in stormwater runoff
- Bioaccumulation in marine sediments
Pathways of Exposure
- Inhalation during exterior paint and stain application
- Dermal contact with treated shower curtains and bath products
- Skin contact with treated outdoor textiles
Building Materials with Zinc Pyrithione
Listed alphabetically — product categories where this specific substance appears.
Antimicrobial Textile Treatments
Deck & Outdoor Stain Additive
Exterior Antimicrobial Paint
Marine Antifouling Coatings
Treated Shower Curtains & Bath Mats