The EU Commission has recently confirmed that certain silver compounds will not be approved for use in biocidal (antimicrobial) products in the EU. This could have implications within and well beyond the EU—including in the US and in markets where various “silver-treated” products are manufactured for world-wide distribution.

Biocidal products are used to protect against harmful organisms such as viruses, bacteria and mold. The EU regulates the placing on the market and use of biocidal products via the EU's Biocidal Products Regulation (EU) 528/2012 (BPR). The BPR applies directly across all EU Member States and restricts the placing on the market of biocides in substances, mixtures and articles.

The determinations follow evaluations undertaken of applications for use of silver copper zeolite, silver sodium hydrogen zirconium phosphate, and silver zeolite. The applications were for use of the substances in certain product types: disinfectants and algaecides not intended for direct application to humans or animals (type 2) and film preservatives (type 7).

The European Chemicals Agency's (ECHA) Biocidal Products Committee initially concluded in October 2018 that the substances should not be approved for use in these product types. Following further consideration of the draft decisions, and representations from the United States, this position has now been confirmed and Commission Implementing Decisions will shortly be published.

Since March 2017, when transitional provisions ran out, articles placed on the EU market, including those imported from outside the EU, may only be treated with biocidal products containing active substances approved in the EU.

Biocidal products are broadly defined as:

"…any substance or mixture, in the form in which it is supplied to the user, consisting of, containing or generating one or more active substances, with the intention of destroying, deterring, rendering harmless, preventing the action of, or otherwise exerting a controlling effect on, any harmful organism by any means other than mere physical or mechanical action, — any substance or mixture, generated from substances or mixtures which do not themselves fall under the first indent, to be used with the intention of destroying, deterring, rendering harmless, preventing the action of, or otherwise exerting a controlling effect on, any harmful organism by any means other than mere physical or mechanical action. A treated article that has a primary biocidal function shall be considered a biocidal product". (Article 3(1)(a) BPR).

"Treated article" means:

"…any substance, mixture or article which has been treated with, or intentionally incorporates, one or more biocidal products". (Article 3(1)(l) BPR).

A treated article may, depending upon claims made for it, itself fall within the definition of a biocidal product. However, the BPR also contains provisions which apply to treated articles which are themselves not biocidal products. Such treated articles may not be placed on the market in the EU unless all active substances contained in the biocidal products that it was treated with or incorporates are approved for use in the EU for the specific product type.

It has been argued that the EU's decisions in relation to these silver compounds, introduced a new threshold of requiring "benefit" to be demonstrated and that this was not justified as a technical barrier to trade on public health or environmental grounds. The EU's response has been that ECHA had not introduced any new criteria in making these decisions, it had only applied the standard of "efficacy" in line with the requirements of the BPR. It was the responsibility of the applicant seeking approval for a product use to show that the biocidal product was effective in the manner claimed for it.

The EU position remains that making available on the market a biocidal product which is not sufficiently effective is a public health and environmental health issue. It may unnecessarily expose humans, animals and the environment to biocidal active substance, generate health and/or environmental risks and impacts, and may also contribute to the development of resistance to biocides leading to other health and/or environmental issues. The approach of the EU's BPR is to try and make the use of biocidal products sustainable by limiting their use to the minimum necessary.

It remains open to any applicant to seek approval under the BPR for the particular biocidal uses of these silver compounds. However, sufficient data to demonstrate both safety and efficacy will be required.

These decisions and the factual basis for them could have profound implications for manufacturers not only in the EU but elsewhere, including in the US where there a considerable number of silver compounds already authorized for use in the manufacture of products that contain these forms of silver as an antimicrobial "materials preservative".

In the US, products that incorporate silver as a preservative and which bear claims with regard to the presence of the silver compound as an antimicrobial preservative are subject to US regulation as "pesticides" under US law. When a product claims to control microorganisms (such as bacteria, mould, mildew, fungi) other than on or in humans or animals, the product is considered to be an antimicrobial product, and such products are regulated under the US law concerning pesticides. See generally, the Federal Insecticide, Fungicide and Rodenticides Act (FIFRA), 7 U.S.C. §§136-136y.

Thus, in the US, the form of silver preservative incorporated to such commodities must be registered with the US Environmental Protection Agency for use as a "materials preservative". Moreover, when distributed in the US, the commodities (articles) that are preserved using the silver additives may only be marketed using very modest claims, either claims that are specifically authorized by EPA (if the article itself has been registered by that agency) or a restricted set of claims that may be made for "treated articles" that are exempt from the EPA's pesticide registration requirements. However, to qualify for this exemption, the additive that is incorporated into the treated article must have been registered with EPA and labeled specifically for the purpose of being used as a materials preservative. For such products to remain "exempt" the treated article must not be marketed with claims that the article, or the additive within it, have an antimicrobial effect on anything that is outside of the article itself. (The "treated articles" exemption has been codified within EPA's pesticide regulations at 40 CFR §152.25(a)). If the treated article conforms to the requirements of the regulation and is marketed solely within its limitations, the article is effectively exempt "from all provisions of FIFRA". 40 CFR §152.25.

The ECHA determinations underlying the EU decisions fundamentally call into question the effectiveness of certain silver based compounds as antimicrobials, even as material preservatives. This is likely to raise concerns for makers of products that rely on the same chemistries in the US. Although the US pesticide registration regulations require the makers of antimicrobial products that make claims to control pathogens that are harmful to humans to demonstrate the effectiveness of their disinfectants and sterilants as part of their registration dossier. The makers of materials preservatives generally are not required to submit to EPA data demonstrating the preservative's effectiveness as a condition of registration. It is possible the US EPA might, in light of the ECHA findings, issue a "data call-in" notice in the US seeking to collect existing data on the substances effectiveness. Moreover, Section 6(a)(2) of the US pesticides law has been interpreted by EPA to require the timely submission to EPA of data which show that a "public health" pesticide (e.g., a hospital grade disinfectant or sterilant) is ineffective.

Companies manufacturing or using the affected silver compounds in their products will not only need to reconsider whether they are still permitted to place these on the market in the EU, they will also need to ask themselves in what other jurisdictions such findings might create impediments in the market, or even new affirmative reporting obligations.

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