The risks posed by a substance are determined by both its hazardous properties (potential to cause adverse human health or ecological effects) and the amount or extent of exposure to people and the environment.
When needed, the Government implements risk management measures under CEPA 1999 and other federal acts to help prevent or reduce potential harm.
The Government concluded that chlorhexidine and its salts are harmful to the environment, but not to human health at levels of exposure considered in the assessment. The chlorhexidine moiety may cause adverse effects on aquatic organisms. Risk management actions were proposed to help address these ecological concerns.
The screening assessment under the Chemicals Management Plan (CMP) focused on the chlorhexidine moiety. It addressed chlorhexidine and its salts, which includes, but is not limited to, chlorhexidine, chlorhexidine diacetate, chlorhexidine dihydrochloride, and chlorhexidine digluconate.
Chlorhexidine diacetate was initially part of Batch 12 of the Challenge Initiative of the CMP (then referred to as chlorhexidine acetate). However, to consider exposure from all potential sources of the chlorhexidine moiety, a subsequent screening assessment to address a broader group of substances was published, namely the screening assessment for chlorhexidine and its salts.
These substances do not occur naturally in the environment.
According to information gathered by the Government, these substances are used as antiseptics and antimicrobial preservatives in products, such as cosmetics, natural health products, prescription and non-prescription drugs for human or veterinary uses, and hard-surface disinfectants.
Human and ecological exposures
Canadians may be exposed to these substances through the use of products available to consumers, such as cosmetics (for example, body moisturizer, lipstick, and lip balm) and natural health products (for example, sunscreen and mouthwash).
These substances may be released to the environment through discharges from wastewater treatment systems, from the manufacture of chlorhexidine-based products and from consumer use of products containing these substances.
Key health and ecological effects (hazard)
Potential effects on the liver were considered to be the critical effects identified for characterizing the risk to human health in the screening assessment.
In the environment, the chlorhexidine moiety has the potential to cause adverse effects to aquatic organisms at low concentrations.
Risk assessment outcomes
Based upon a comparison of levels to which Canadians may be exposed to chlorhexidine and its salts, and the levels associated with health effects, the risk to human health from these substances is considered to be low.
Considering all information presented in the screening assessment, it was determined that there is risk of harm to the environment from chlorhexidine and its salts.
Screening assessment conclusions
The Government concluded that chlorhexidine and its salts are not harmful to human health at levels of exposure considered in the assessment.
The Government also concluded that chlorhexidine and its salts are entering or may enter the environment at levels that are harmful to the environment.
Also, the chlorhexidine moiety was found to meet the persistence criteria, but not the bioaccumulation criteria as set out in the Persistence and Bioaccumulation Regulations of CEPA 1999.
Preventive actions and risk reduction
The proposed order adding chlorhexidine and its salts to Schedule 1 to CEPA 1999, also called the List of Toxic Substances, was published for a 60-day public comment period ending on May 5, 2021. Adding a substance to the list does not restrict its use, manufacture or import. Rather, it enables the Government to take risk management actions under CEPA 1999.
Publication of the risk management approach aims to inform stakeholders of proposed risk management options and continue discussion about their development. The Government is considering the following risk management actions to address ecological concerns:
Implementing an environmental performance agreement (EPA) and a code of practice under Section 54 of CEPA 1999 to minimize the release of chlorhexidine and its salts to the environment from the industrial use of these substances.
Risk management actions may evolve, through the consideration of assessments and risk management options published for other substances. This is to ensure effective, coordinated, and consistent risk management decision-making.
Chlorhexidine and its salts were added to the National Pollutant Release Inventory (NPRI). Further details and updates are found on that program's website.
Use the Substances Search tool to find substances that are referenced in certain legislative or regulatory instruments or on Government of Canada websites.
Related resources
These substances may be found in products available to consumers. Canadians should follow any safety warnings and directions related to the product and dispose of products responsibly.
Health Canada published a summary safety review on the potential link between non-prescription topical antiseptic chlorhexidine products and serious allergic reactions.
The screening assessment focused on potential risks from exposure of the general population of Canada, rather than occupational exposure. Hazards related to chemicals used in the workplace are defined within the Workplace Hazardous Materials Information System (WHMIS). For information concerning workplace health and safety and what steps to take in the workplace, Canadians should consult their employer or the Occupational Health and Safety Regulator in their jurisdiction for information.
