Zinc pyrithione

  • Zinc bis [2- pyridinthiolat ]-N, N' -dioxide
  • 2- pyridinethiol -1 -oxide zinc salt
  • Zinc 2- mercaptopyridine -N-oxide

D11AC10, D11AX12

An off-white powder

240 ° C ( decomposition)

Insoluble in water, slightly soluble in many organic solvents


160 mg · kg -1 ( LD50, mouse, oral)

Template: Infobox chemical / molecular formula search available

Zinc pyrithione ( INN) is the zinc salt of pyrithione ( pyridine -2-thiol -1-oxide ). It is a colorless solid having antifungal and antibacterial properties. It is known by several chemical and trade names, was described in the 1930s for the first time and finds extensive use, especially in industry and cosmetics.


Zinc pyrithione is chemically incompatible with paints that are based for curing on metal carboxylate. When used in water-based acrylic paint, a binder for the iron ion is required for a high iron content in the water. Zinc pyrithione is slowly decomposed by ultraviolet radiation, making it for years also resistant to direct sunlight. This and so far only partly understood biological effects that extend to genetics and metabolism of many vegetable as animal cell types, depending on the situation make a desired effect or an unwanted side effect dar.



The best known is zinc pyrithione for use against excessive dander and mold. The medical diagnoses here include seborrheic dermatitis and other eczema, psoriasis ( psoriasis), athlete's foot and other forms of tinea.


Due to its low solubility in water (8 ppm at neutral pH) to zinc pyrithione is suitable for use in outdoor paints and other products that provide protection against mold. The antifungal effect seems to result from its ability to interrupt the transport of substances across the cell membrane by blocking the proton pump that feeds the transport mechanism. Fungi are able to inactivate pyrithione in low concentrations. In addition, zinc pyrithione an effective algaecide.

Zinc pyrithione is also used for antibacterial treatment of sponges (especially from 3M, Brand: Scotch).

Adverse effects

The advertised by some providers antibacterial properties of zinc pyrithione against pathogens from the family of streptococci and staphylococci can be seen under the well known caveat that applies to all external applications of this kind: it is to reduce the physiological colonization, development of resistance by promoting MRSA and detriment to the acid mantle of the skin.

While the EU had declared safe in a classification from 2002 zinc pyrithione even for human, veterinary and environmental health, urged the U.S. EPA in a review from 2004, zinc pyrithione WOULD even in the lowest concentration (ppb ) as a potent poison on fish, invertebrates and aquatic plants in fresh and salt water. It is possible that this compound as an " endocrine disruptor " hormone-like side effects unfold, so there is need for further research. Given the use of the compound as a growth retardant protective coating in ship these concerns were repeated.

In primary skin cell culture zinc pyrithione induces massive expression of heat shock proteins - encoding genes in keratinocytes and melanocytes, which can lead to poly (ADP- ribose) polymerase - 1 -dependent ATP depletion and necrotic cell death. The compound is reduced even in the nanomolar concentration range and the genetic integrity of important immune cells ( thymocytes, lymphocytes) in cell cultures of mice and humans.