Alkyl Halides Group - information sheet
Publications summarized:
On this page
Overview
- The Government of Canada conducts risk assessments of substances under the Canadian Environmental Protection Act, 1999 (CEPA) to determine whether they present or may present a risk to human health or to the environment.
- 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 to which people or the environment are exposed.
- When needed, the Government applies risk management instruments under CEPA and other federal acts to help prevent or reduce potential harm.
- The Government concluded that 1-bromopropane may be harmful to human health due to potential exposure from certain products available to consumers and its association with developmental effects. 1-Bromopropane is also associated with neurotoxicity and potential carcinogenicity.
- The Government is proposing regulatory actions that would restrict the use of 1-bromopropane in silicone mold release spray (anti-stick lubricant), electrical equipment cleaner spray, textile ink remover spray and automotive air conditioning flush.
- The Government also concluded that bromoethane, chloroethane, and trans-1,2-chloroethane are not harmful to human health at levels of exposure considered in the assessment.
- The ecological hazard and exposure potentials of these 4 substances were classified using the Ecological Risk Classification of Organic Substances (ERC) Approach. None of the substances in this group are concluded as causing harm to the environment, at levels of exposure considered in the assessment.
About these substances
- Details on the substance names and CAS RNs are found in the summary of publications section of the Alkyl Halides Group web page.
- The assessment focused on 4 of 8 substances referred to as the Alkyl Halides Group under the Chemicals Management Plan (CMP). These 4 substances are bromoethane, chloroethane, 1-bromopropane, and trans-1,2-chloroethane.
- The other 4 substances are aryl halides and were determined to be of low concern to human health and the environment through other approaches. The conclusion for the substance with the CAS RN 77-47-4 is provided in the Screening Assessment for Substances Identified as Being of Low Concern using the Ecological Risk Classification of Organic Substances and the Threshold of Toxicological Concern (TTC)-based Approach for Certain Substances. The conclusions for the substances with the CAS RNs 74-88-4, 126-99-8 and 630-20-6 are provided in the Screening Assessment for the Rapid Screening of Substances with Limited General Population Exposure.
- Trans-1,2-dichloroethane was considered a priority for risk assessment based on the results of the identification of risk assessment priorities process.
- The 4 substances included in the Alkyl Halides Group are human-made. Bromoethane and 1-bromopropane are also naturally occurring.
- According to information gathered by the Government, 3 of the 4 substances in the Alkyl Halides Group may be found in Canada in products available to consumers, such as liquid or aerosol cleaners or degreasers, aerosol starting fluids (engine-starting aid), air conditioning refrigerant flush, silicone mold release spray, spray foam insulation, and textile ink remover spray.
Human and ecological exposures
- The assessment indicated that people in Canada may be exposed to the 4 substances included in the Alkyl Halides Group through environmental sources, such as indoor and ambient air.
- The main source of exposure to bromoethane is from indoor and outdoor air. Bromoethane is not anticipated to be found in products available to consumers.
- The main source of exposure to chloroethane is from indoor and outdoor air, and the use of starting fluid spray.
- 1-Bromopropane exposure is expected from indoor air, and from the use of silicone mold release spray, electrical equipment cleaner spray, automotive air conditioning flush, and textile ink remover spray.
- People in Canada may be exposed to trans-1,2-dichloroethane mainly from indoor and outdoor air and from the use of textile spot removers. Exposure may also occur from the use of other products available to consumers.
- According to the information considered under the ERC Approach, bromoethane and 1-bromopropane were identified as having low ecological exposure potential, while chloroethane and trans-1,2-dichloroethane were classified as having a high ecological exposure potential based on their long half-lives in air and large annual import quantities.
Key health and ecological effects (hazard)
- To help inform the health effects characterization in the assessment, international reports on these substances were considered, among other sources of information. This included assessments by the Organisation for Economic Co-operation and Development (OECD) and the United States Environmental Protection Agency, among others. These reviews were used to inform the health effects characterization in the assessment.
- Bromoethane has been classified by the European Chemicals Agency (ECHA) as "suspected of causing cancer" in the Global Harmonized System (GHS). Changes to cells in the nasal cavity and the potential to cause cancer were considered to be critical effects considered in the risk assessment.
- Chloroethane has been classified by ECHA as "suspected of causing cancer" in the GHS. The critical effects for chloroethane were developmental toxicity and cancer.
- 1-Bromopropane has been classified by the International Agency for Research on Cancer (IARC) as "possibly carcinogenic". This substance was also classified by ECHA as a "presumed reproductive toxicant" in the GHS. The critical effects identified for characterizing risk to 1-bromopropane include developmental effects, neurotoxicity and cancer.
- The critical effects for trans-1,2-chloroethane were immunotoxicity and developmental effects.
- According to information considered under the ERC Approach, trans-1,2-dichloroethane was identified as having a low ecological hazard potential while bromoethane, chloroethane and 1-bromopropane were identified as having moderate ecological hazard potentials based on increased level of ecotoxicity.
- While 1-bromopropane is not controlled under the Montreal Protocol on Substances That Deplete the Ozone Layer, the substance has been identified as an ozone-depleting substance with a relatively small ozone-depleting potential.
Consideration of subpopulations who may have greater susceptibility or greater exposure
- There are groups of individuals within the Canadian population who, due to greater susceptibility or greater exposure, may be more vulnerable to experiencing adverse health effects from exposure to substances.
- Certain subpopulations are routinely considered throughout the risk assessment process, such as infants, children, and people of reproductive age. For instance, age-specific exposures are routinely estimated, and developmental and reproductive toxicity studies are evaluated for potential adverse health effects.
- Additionally, indoor air monitoring data from First Nations communities were included in the exposure assessment to take into account the potential for elevated exposure in these communities. People living near commercial or industrial facilities were also considered in the assessment of 1-bromopropane.
Risk assessment outcomes
- Assessments focus on information critical to determining whether substances are harmful to human health or the environment under CEPA. This is done by considering scientific information, including information, if available, on subpopulations who may have greater susceptibility or greater exposure, vulnerable environments and cumulative effects and by incorporating a weight-of-evidence approach and precaution.
- Based upon a comparison of levels to which people in Canada may be exposed to 1-bromopropane from certain products available to consumers and levels associated with health effects, it was determined that this substance may pose a risk to human health.
- It was determined that the risk to human health from bromoethane, chloroethane and trans-1,2-chloroethane is low. This was based upon a comparison of levels to which people in Canada may be exposed to each of these substances and levels associated with health effects.
- Based upon the outcome of the ERC Approach, all 4 substances assessed are considered unlikely to be causing ecological harm.
Assessment conclusions
- The Government concluded that 1-bromopropane may be harmful to human health at levels of exposure considered in the assessment. The Government also concluded that the remaining 3 substances are not harmful to human health at levels of exposure considered in the assessment.
- The Government concluded that none of the substances are entering the environment at concentrations that are harmful to the environment.
Preventive actions and risk reduction
- The Government intends to propose the addition of 1-bromopropane to Part 2 of Schedule 1 to CEPA. Adding a substance to Schedule 1 does not, in itself, restrict its use, manufacture or import. Rather, it enables the Government to take enforceable risk management actions under CEPA.
- Toxic substances that pose the highest risk (that is, meet certain criteria) are added to Part 1 of Schedule 1. These are prioritized for total, partial or conditional prohibition.
- Other toxic substances are added to Part 2 of Schedule 1 and are prioritized for pollution prevention actions, which may include prohibition.
- Publication of the risk management approach aims to inform interested parties of proposed risk management actions and continue discussions about their development. The risk management approach indicated that the Government is considering the following actions to address human health concerns:
- Measures to help reduce exposures to 1-bromopropane from silicone mold release spray, electrical equipment cleaner spray, textile ink remover spray and automotive air conditioning flush by developing regulations that would restrict the use of 1-bromopropane in these product types.
- Additional information is being sought by the Government to inform risk management decision-making. Details can be found in the risk management approach, including where to send information during the public comment period, ending June 24, 2026.
- Risk management actions may evolve through consideration of assessments and risk management actions published for other substances. This is to ensure effective, coordinated, and consistent risk management decision-making.
Where to find updates on risk management actions
Related resources
- Substances in the Alkyl Halides Group may be found in products available to consumers. People in Canada should follow any safety warnings and directions related to the product and dispose of products responsibly.
- Assessments conducted under CEPA focus on risks of exposure of the general population, including populations who may be disproportionately impacted. Hazards related to chemicals used in the workplace are defined within the Workplace Hazardous Materials Information System (WHMIS). The Government of Canada recognizes that it is the responsibility of the federal, provincial and territorial occupational health and safety organizations to coordinate legislation for the safe use of chemicals in the workplace. We are working to support this role by integrating the information, tools, and/or technical expertise of the CMP and Health Canada's Workplace Hazardous Products Program.
