Developments in Biocide Regulation

Background

Biocides in paints and coatings are used to prevent microbial growth and degradation of paint film after application, during production and storage. Increasingly, paint products have embraced waterborne technology to develop low VOC emitting paints, requiring the use of “in-can” preservatives. Without these, the paint can spoil and, in extreme cases, microbial decomposition can generate gases that rupture containers.

Canada, EU and the US are evaluating several biocides used in paints and coatings for risk to human health and the environment. The U.S. has published draft risk assessments of several biocides common to paint and coatings as part of its routine registration review program, requiring revised risk assessments every 15 years. These include evaluation of isothiazolinones, expected by Fall 2023.

As of Spring 2024, EPA published an ANPRM (Advanced Notice of Proposed Rulemaking) to gather information relevant to revising its current treated articles exemption that would authorize EPA to directly regulate products containing biocide preservatives, including paint. Such products are currently exempt from regulation under the treated articles exemption. EPA is authorized to implement conditions for the treated articles exemption to apply. In the past, EPA has regulated rates of use of a biocide in a paint, but not conditions related to downstream use of a paint due to preservative content.

Applying its assumed authority, EPA has proposed requiring PPE for professional painters with a mandatory label on paint products containing the biocide diuron. The diuron proposal is a “test case.” EPA anticipates taking a similar approach for other biocides more commonly used in the paint and coatings industry, including the isothiazolinones, such as BIT, MIT, CMIT, etc. The ANPRM suggests changes to underlying regulations that would clarify EPA’s position about its legal authority to make this change. The alternative is for EPA to implement very low use rates, to mitigate its identified level of risk to paint applicators.

As of Spring 2024, EPA published an ANPRM (Advanced Notice of Proposed Rulemaking) to gather information relevant to revising its current treated articles exemption that would authorize EPA to directly regulate products containing biocide preservatives, including paint. Such products are currently exempt from regulation under the treated articles exemption. EPA is authorized to implement conditions for the treated articles exemption to apply. In the past, EPA has regulated rates of use of a biocide in a paint, but not conditions related to downstream use of a paint due to preservative content.

Applying its assumed authority, EPA has proposed requiring PPE for professional painters with a mandatory label on paint products containing the biocide diuron. The diuron proposal is a “test case.” EPA anticipates taking a similar approach for other biocides more commonly used in the paint and coatings industry, including the isothiazolinones, such as BIT, MIT, CMIT, etc. The ANPRM suggests changes to underlying regulations that would clarify EPA’s position about its legal authority to make this change. The alternative is for EPA to implement very low use rates, to mitigate its identified level of risk to paint applicators.

As of Spring 2024, EPA published an ANPRM (Advanced Notice of Proposed Rulemaking) to gather information relevant to revising its current treated articles exemption that would authorize EPA to directly regulate products containing biocide preservatives, including paint. Such products are currently exempt from regulation under the treated articles exemption. EPA is authorized to implement conditions for the treated articles exemption to apply. In the past, EPA has regulated rates of use of a biocide in a paint, but not conditions related to downstream use of a paint due to preservative content.

Applying its assumed authority, EPA has proposed requiring PPE for professional painters with a mandatory label on paint products containing the biocide diuron. The diuron proposal is a “test case.” EPA anticipates taking a similar approach for other biocides more commonly used in the paint and coatings industry, including the isothiazolinones, such as BIT, MIT, CMIT, etc. The ANPRM suggests changes to underlying regulations that would clarify EPA’s position about its legal authority to make this change. The alternative is for EPA to implement very low use rates, to mitigate its identified level of risk to paint applicators.

Both the U.S. and Canada are raising concerns for inhalation by spray application of paint and inhalation by workers during paint formulation, even for biocides with low rates of volatilization. In December, Canada’s PMRA (Pest Management Regulatory Authority) published a final decision restricting six biocides used as preservatives in coatings. Restrictive measures includes reduced use rates, discontinuation, requiring closed transfer systems and additional PPE requirements. The six biocides at issue are: folpet, ziram, diodofon, chlorothalonil, sodium omadine and dazomet. PMRA is also managing distribution of information to workers requiring protective measures and conveying detailed hazard information. PMRA will implement the program for paints containing: chlorothalonil, diodofon and dazomet.

To address concerns about PMRA’s process, ACA is working with CPMA (Canadian Paint and Coatings Association) to host joint meeting with PMRA and EPA to provide important context to biocide usage in the paint formulation process and how agencies can incorporate industry practices into its risk evaluations. To this end, stakeholder met with the agencies last Fall and are currently scheduling a follow-up meeting. ACA is also working with the Center for Biocide Chemistries to develop a survey related to current safety practices of professional painters.

U.S. EPA has noted risks associated with spray airless spray application of paints and coatings by consumers and inhalation of vapors by workers during formulation. EPA is also poised to publish several proposed interim decisions (PIDs) during 2023 that will describe EPA’s proposed risk mitigation strategies. In April 2022, EPA published PIDs for diuron, folpet and carbendazim. To address concerns about airless spray application by commercial painters, EPA proposed label changes on paint containers that prescribe respiratory protection, gloves and other PPE. EPA also proposed lower use rates to address exposures to consumers caused by airless spray application. As of April 2024, EPA has not finalized these proposals due to concerns regarding its legal authority to implement label changes on paint containers. EPA is also further considering additional information regarding the underlying risk evaluations.

The EU has also scheduled final risk mitigation requirements for several isothiazolinones by the end of 2023. Meanwhile, the EU has revised hazard classifications for several of these, requiring revised hazard labels at lower thresholds than the GHS thresholds. Some hazard classifications automatically bar the biocide from approval. Hazard classification of a biocide may also prevent manufacturers from using ecolabel and other similar marks on paint and coatings products with the classified biocide.

Regulators express concerns about skin sensitization, carcinogenicity and reproductive toxicity, often based on a review of hazard characteristics and/or use in products that are directly applied to the skin. The paints and coatings industry faces challenges in providing regulators with accurate exposure information specific to paint and coatings products.

ACA Action

ACA has developed a Biocide Working Group to discuss and develop an advocacy strategy. Through the working group, ACA meets regularly with EPA and biocide manufacturers to provide insight from downstream formulators’ perspective. ACA will continue to advise both its Biocide Working Group and its Product Stewardship Committee about developments.

ACA Staff

Riaz Zaman
Senior Counsel, Government Affairs