Zinc Pyrithione: What It Is and Why It's Used (flagship)

Origin

Zinc pyrithione was first synthesised in the 1930s and its antifungal properties were identified shortly thereafter. Its application to dandruff treatment followed from the understanding that dandruff (seborrhoeic dermatitis) is associated with overgrowth of Malassezia, a fungus naturally present on the scalp. Shampoos containing zinc pyrithione became a major commercial category from the 1960s onward.

Why It's Used

It functions as an antifungal and antibacterial agent by disrupting membrane transport in the target organism. In anti-dandruff shampoos in the United States, it is regulated as an OTC drug active with a specific permitted concentration range (1–2%) and required label language. In the EU, it is regulated as a cosmetic ingredient with restrictions, and it is also regulated as a biocide under the Biocidal Products Regulation for non-rinse applications.

Elsewhere

Zinc pyrithione is used as a biocide in antifouling marine coatings, plastics, and textiles to prevent microbial degradation. Its use in these non-cosmetic applications is governed by separate biocide legislation from its cosmetic use.

What the Framework Sees

Question Zero, completed.

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