Zinc Pyrithione: What is it, and why is it being reclassified?

As of March 1st, 2022, the European Commission have officially implemented the Commission Delegated Regulation 2020/1182, which includes a revised list of prohibited ingredients for Annex I and Annex VI. An unexpected addition to the list of prohibited substances is Zinc Pyrithione, an active ingredient that has been commonly used within the cosmetics and construction industries for decades.

What is Zinc Pyrithione?

Zinc Pyrithione (ZPT) is a broad-spectrum antimicrobial that has proven efficacy against fungi, Gram-positive, and Gram-negative bacteria.

In the cosmetics industry, it has been used for over 50 years to effectively treat dandruff and seborrheic dermatitis and is the currently the main active ingredient used in anti-dandruff shampoos from some of the biggest brands. Its use has expanded to include other benefits such as skin hygiene in medical cosmetics, with its antibacterial and antifungal efficacy being used to treat psoriasis, eczema, ringworm and athlete’s foot in topical creams and washes.

For non-medical purposes, ZPT is particularly effective in dry-film anti-fungal applications. It is frequently used in exterior paints to protect against mildew and mould, with the substance acting as a chemical preservative to protect against unwanted microbial growth and degradation within the treated paint. ZPT is most commonly available in powder form and has a high decomposition temperature that makes it ideal for heat sensitive applications. The active has also been approved for use as a chemical biocide in a wide range of indoor and outdoor treated article applications, including textiles, construction materials, adhesives, plastics, leather, caulks, sealants, and marine anti-fouling paints.

Why is it being reclassified in the EU?

First drafted in August 2020, Commission Delegated Regulation 2020/1182 added twenty-three chemicals to the list of prohibited substances in Annex VI, formally classifying them as carcinogenic, mutagenic, or toxic to reproduction. After entering into force on the 1st of March 2022, Regulation 2020/1182 has banned ZPT from being used in all EU materials, whether cosmetic or industrial, due to its reproductive toxicity.

Formally, ZPT now has the reclassification as a “Reprotoxic Category 1b” under the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) regulation of the EU. It has also been allocated an acute M-factor of 1000 to the environmental classification. REACH, who are governed by the European Chemicals Agency (ECHA) in the EU, prohibit the use of ingredients that classify as reproductively toxic unless 2 distinctive conditions can be proven: 1. The ingredient is safe under certain conditions, and 2. The raw material is irreplaceable.

While the Scientific Committee on Consumer Safety (SCCS) issued a conclusion that ZPT is safe for consumers when integrated within a product at a dosage rate less than 1%, they could not confirm that ZPT is an irreplaceable chemical agent. The active substance therefore did not meet the exemption conditions needed to remove it from Regulation 2020/1182. This has led to ZPT fitting the exclusion criteria according to Biocidal Product Regulation (BPR) No. 528/2012 in the EU.

Global impact of the Zinc Pyrithione reclassification

Currently, ZPT has only been banned within the EU under the BPR and is still widely used throughout the rest of the world. The US in particular still include ZPT as the main active ingredient in a vast range of their products, namely shampoo and wood preservative applications. However, given the only recently released evidence to suggest that ZPT is toxic to reproduction, BioCote® have taken immediate action and decided to permanently cease the supply of ZPT based additives for use in treated articles.

The discontinuation will not only apply within the EU, but to our entire global customer base. As experts in our field, BioCote® are trusted for our intrinsic understanding of antimicrobial technology, and therefore feel that it would be irresponsible of us to sell any additives that we cannot unanimously say are safe for use in treated articles. It would also be against our philosophy of open and honest customer support, which we hold to a very high standard and is central to our business ethos.

What is a suitable alternative?

Since BioCote® are taking a proactive stance to not supply a substance that REACH have sanctioned as harmful, we have been working hard to offer our customers a viable alternative to using ZPT within their treated products.

Iodopropynyl Butylcarbamate (IPBC) is a broad-spectrum fungicide that would generally be suitable as an alternative to ZPT, both for treated article applications and medical applications. The water-soluble preservative is used globally in paints, coatings, and cosmetic industries, and is supplied in the form of off-white powder. IPBC has shown particular success for metalworking fluids and for wood preservatives, with the dry-film preservative exhibiting high efficacy in controlling fungal growth on treated wood coating surfaces.

BioCote® additives are not intended for cosmetic purposes, and we do not supply additives for use in rinse-off cosmetic products. We do however offer an additive with an active substance of IPBC that is intended to preserve treated articles, and the newly formulated additive will act as an ideal replacement for any businesses looking to move away from using ZPT. Our IPBC additive offers excellent anti-fungal dry-film protection for interior and exterior applications such as paints, coatings, stuccos, adhesives, and other industrial applications. It can also be used in the leather, textile, and paper industry, and has proven superior fungal control in wood preservatives. It is suited for water- and solvent borne systems and can also be mixed with dry powder products.

Learn more about our Zinc Pyrithione replacement today

Please reach out to a member of the BioCote® team via our Contact Form or directly on +44 (0) 2477 712 489 for more information about our new IPBC additive.

This content piece discusses topics relating to BioCote® technology and does not apply to treated articles. If you would like to discuss the above topic within your own marketing collateral in relation to your treated product, please reach out to your dedicated BioCote® Account Manager for support.