On February 12, 2025, the Government of Canada officially added 2,4,11,13-tetraazatetradecanediimidamide, N,N″-bis(4-chlorophenyl)-3,12-diimino-(chlorhexidine) and its salts to Part 2 of Schedule 1 under the Canadian Environmental Protection Act, 1999 (CEPA) through Order SOR/2025-13. This regulatory action, published in the Canada Gazette, follows scientific assessments that identified environmental risks associated with chlorhexidine compounds, prompting the government to prioritize pollution prevention actions for these substances.

Why is Chlorhexidine Now Considered Toxic?

In 2019, a screening assessment conducted by Environment and Climate Change Canada (ECCC) and Health Canada concluded that chlorhexidine (CAS no 55-56-1) and its salts meet the environmental toxicity criteria outlined in paragraph 64(a) of CEPA. Key findings highlighted that:

• Chlorhexidine persists in aquatic environments and poses long-term risk to aquatic and benthic organisms, with algae being particularly sensitive.

• Although its bioaccumulation potential is low, the substance remains in water, sediment, and soil for prolonged periods of time.

• Releases primarily come from consumer use, wastewater discharge, and industrial formulation processes.

Despite these environmental concerns, the assessment found no significant risks to human health at current exposure levels from products such as antiseptics, cosmetics, and disinfectants.

Regulatory Impact and Next Steps

The addition of chlorhexidine and its salts to Part 2 of Schedule 1 allows the government to develop pollution prevention measures, which may include restrictions or prohibitions on certain uses. Unlike substances listed in Part 1 of Schedule 1, which require immediate bans or severe restrictions, substances listed in Part 2 are managed through targeted risk reduction strategies.

Canada’s Chemicals Management Plan (CMP) will now oversee the development of risk management measures, with stakeholder consultations expected before any final regulations come into effect. The government has also taken steps to:

• Include chlorhexidine in the National Pollutant Release Inventory (NPRI), which requires industry to report its environmental releases.

• Establish an Environmental Performance Agreement (EPA) with industrial formulators to limit chlorhexidine discharges to wastewater.

International and Domestic Context

While Canada has now classified chlorhexidine and its salts as toxic to the environment, regulatory actions vary worldwide:

• United States: Chlorhexidine digluconate is under review by the U.S. Environmental Protection Agency (EPA) for its safety as an antiseptic.

• European Union: Chlorhexidine is registered under REACH (Registration, Evaluation, Authorisation, and Restriction of Chemicals) to monitor its effects on human health and the environment.

• Canada: The country will now prioritize pollution prevention strategies while continuing to allow the use of chlorhexidine in medical and personal care products.

What Happens Next?

The Canadian government is expected to initiate consultations with industry stakeholders, environmental groups, and health agencies to develop risk management tools. These measures could range from manufacturing and disposal guidelines to specific restrictions in industrial applications.

The full regulatory order can be accessed in the Canada Gazette here, and stakeholders have until April 14, 2025, to submit comments on future risk management plans.

The Canadian Environmental Protection Act 1999 (CEPA 1999) remains Canada’s most important chemical control law, requiring assessments of new substances placed on the market after 1994. It mandates reviews of substances introduced before 1994, ensuring their safety for human health and the environment. Substances not on the Domestic Substances List (DSL) cannot be manufactured or imported without prior government approval, reinforcing Canada’s commitment to regulating hazardous chemicals effectively.

Bill S-5, known as the Strengthening Environmental Protection for a Healthier Canada Act, was adopted in 2023, marking a major amendment to CEPA for the first time in over two decades. It enhances protection for vulnerable communities, advances Indigenous reconciliation, strengthens chemical management strategies, and reduces reliance on animal testing. The government has until June 2025 to develop a comprehensive new plan for managing chemicals and integrating the right to a healthy environment into CEPA.

Canada has also begun transitioning to the seventh revised edition of the Globally Harmonized System of Classification and Labelling of Chemicals (GHS7), replacing the fifth edition previously in use. This transition will occur over three years to allow industry stakeholders time to comply with updated classification and labeling standards.

Key News from 2024

Modernizing Canada's Environmental Protection: The Journey of Bill S-5

The modernization of the Canadian Environmental Protection Act (CEPA) is underway, embedding the right to a healthy environment into law. The government has launched a public consultation schedule to strengthen CEPA, focusing on chemicals management, environmental monitoring, and reducing vertebrate animal testing. The initiative aligns with global best practices and aims to improve environmental health standards. Read more here.

Health Canada and Environment and Climate Change Canada (ECCC) Announce New Regulatory Developments under Updated CEPA

Following the passage of Bill S-5, Health Canada and ECCC have initiated new regulations focusing on high-risk substances and toxic chemical restrictions. A series of public consultations will take place in 2024–2025 to shape new frameworks for environmental protection, including a watch list approach for hazardous chemicals and strategies to minimize animal testing.Read more here.

Canada Amends Domestic Substances List to Enhance Environmental Protection and Public Health

The Canadian government has amended the Domestic Substances List to regulate three chemicals—AGE, o-CGE, and TGIC—introducing new Significant New Activity (SNAc) requirements. The move ensures that any significant new uses of these substances undergo thorough risk assessment before approval, aligning with the country's Chemicals Management Plan. Read more here.

Government of Canada Publishes Notice on Amendments to the Domestic Substances List Under CEPA

The government plans to unmask the identities of 198 substances currently listed under Part 3 of the Domestic Substances List to improve transparency. Public consultations are open for stakeholders to provide feedback on confidentiality and regulatory impacts, with changes expected to align with Bill S-5’s amendments. Read more here.

Government of Canada Publishes Notice on Amendments to the Domestic Substances List under CEPA

The government plans to unmask the identities of 198 substances currently listed under Part 3 of the Domestic Substances List to improve transparency. Public consultations are open for stakeholders to provide feedback on confidentiality and regulatory impacts, with changes expected to align with Bill S-5’s amendments. Read more here.

Key Dates for 2025

Health Canada amended the Hazardous Products Regulation (HPR) to align with GHS 7 and introduce a new "Chemicals Under Pressure" hazard class from GHS 8. A three-year transition period has been set, requiring full compliance by December 15, 2025.