Ketones 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 ecological hazard and exposure potentials of these substances were classified using the Ecological Risk Classification of Organic Substances (ERC) Approach.
- The Government concluded that MEK and MIBK are harmful to human health due to inhalation exposure from the use of certain products available to consumers. These substances are associated with developmental effects.
- To help reduce human exposures to MEK and MIBK, the Government is proposing regulatory actions.
- While 2,4-PD was considered to pose a risk to human health as a result of the draft screening assessment, further investigation confirmed that 2,4-PD is not currently available in products available to consumers and it was therefore determined to not pose a risk to human health. This substance is being proposed for addition to the Watch List.
- Although some of the other substances in the Ketones Group may be associated with adverse health effects, the risk to human health is considered to be low at levels of exposure considered in the assessment. None of the 10 substances in this group were concluded harmful to the environment at current levels of exposure.
About these substances
- The assessment focused on 10 substances, referred to collectively as the Ketones Group under the Chemicals Management Plan (CMP).
- The summary of publications for the Ketones Group includes details on the substance names and CAS RNs.
- The substances addressed are:
- Subgroup 1: 2-butanone (methyl ethyl ketone; MEK) and methyl propyl ketone (MPK)
- Subgroup 2: 2-pentanone, 4-methyl- (methyl isobutyl ketone; MIBK), methyl isoamyl ketone (MIAK), and diacetone alcohol (DAA)
- Subgroup 3: diacetyl, 2,3-pentanedione (2,3-PD), and acetoin
- Individual: 2,4-pentanedione (2,4-PD) and mesityl oxide (MO)
- All 10 substances in this group are commercially produced (human-made) and are also naturally present in the environment in various plants or foods, or are produced by microbes and other organisms. MEK, diacetyl and acetoin are also naturally produced in humans.
- According to information gathered by the Government, ketones are mainly used as solvents in various products, including products available to consumers such as paints, coatings and adhesives. They may also be used as food flavouring agents, in cosmetics, in natural health products, and as formulants (not active ingredients) in pest control products. These substances may be used in numerous industrial applications.
Human and ecological exposures
- The assessment indicated that people in Canada may be exposed to substances in the Ketones Group as follows:
- Subgroup 1 (MEK and MPK): from air and food (from their natural occurrence and possible use as food flavouring agents), and from products available to consumers, including cosmetics, natural health products, paints and do-it-yourself (DIY) products. MEK was also reported to be released to air as a result of industrial activities.
- Subgroup 2 (MIBK, MIAK, and DAA): from the environment and food (from their natural occurrence and, for MIBK, its potential use as a food flavouring agent), and from the use of products available to consumers, including cosmetics, natural health products, markers, paints and DIY products. MIBK was also reported to be released to air as a result of industrial activities.
- Subgroup 3 (diacetyl, 2,3-PD, and acetoin): from food (due to their natural occurrence and possible use as food flavouring agents) and, for diacetyl and 2,3-PD, from the use of products available to consumers, including cosmetics and air fresheners, respectively.
- People in Canada may be exposed to 2,4-PD from its natural occurrence in food, and to MO from its presence in air and food (due to its natural occurrence and possible use as a food flavouring agent).
- According to the information considered under the ERC Approach, eight substances were identified as having low ecological exposure potential. MEK and DAA, however, were classified as having a high ecological exposure potential based on high reported use quantities in combination with a long half-life (time to decrease in concentration by half) in air.
Key health and ecological effects (hazard)
- Several substances in this group have been reviewed internationally by various organizations, including the Organisation for Economic Co-operation and Development (OECD), the International Programme on Chemical Safety, the United States Environmental Protection Agency, the Agency for Toxic Substances and Disease Registry and the United States National Toxicology Program, among others. These reviews and assessments were used to inform the health effects characterization in the assessment.
- There were limitations to the health effects data available for some substances in this group. Therefore, a comparative approach using similar chemicals, called read-across, was used for assessing potential health effects for these substances with limited data.
- Critical health effects for subgroup 1 included developmental effects for MEK and decreased body weight gain in laboratory studies for both MEK and MPK.
- For subgroup 2, the International Agency for Research on Cancer (IARC) has classified MIBK as "possibly carcinogenic to humans". Effects on the liver (for MIBK and MIAK) and kidney (for MIBK and DAA), as well as developmental effects (for MIBK and DAA), were also identified to be critical effects in the risk assessment.
- Critical effects identified in the assessment for subgroup 3 were the ability to cause cancer (for diacetyl), effects on the respiratory tract (for diacetyl and 2,3-PD), and general systemic effects (for acetoin), based on laboratory studies.
- Using available health effects information, critical effects for the assessment of 2,4-PD and MO were general systemic effects, as well as developmental effects for 2,4-PD.
- According to information considered under the ERC Approach, all 10 substances in this group were identified as having low ecological hazard 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 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. These subpopulations were taken into account in the risk assessment outcomes of the Ketones Group assessment.
- In addition, people living near industrial releases were considered.
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 MEK from the use of some products available to consumers, namely paint or coating removers or strippers (for example, lacquer removers), adhesive removers, degreasers, paint or coating thinners, liquid paints, and various spray products including spray paints and levels associated with critical health effects, it was determined that MEK may pose a risk to human health.
- Similarly, a comparison of levels to which people in Canada may be exposed to MIBK from the use of wood lacquers, liquid paints, and various spray products including spray paints and levels associated with critical health effects, it was determined that this substance may pose a risk to human health.
- Based upon comparisons of exposures to MPK, MIAK, DAA, diacetyl, 2,3-PD, acetoin, 2,4-PD, and MO and levels associated with critical health effects, it was determined that these eight substances do not pose a risk to human health.
- Based upon the outcome of the ERC Approach, the 10 substances in the Ketones Group are considered unlikely to be causing ecological harm at current levels of exposure.
Assessment conclusions
- The Government concluded that MEK and MIBK are harmful to human health at levels of exposure considered in the assessment.
- The Government concluded that MPK, MIAK, DAA, diacetyl, 2,3-PD, acetoin, 2,4-PD, and MO are not harmful to human health at current levels of exposure. It is also concluded that none of the 10 substances in the Ketones Group are entering the environment at concentrations that are causing ecological harm.
Preventive actions and risk reduction
- The Government intends to propose the addition of MEK and MIBK 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 discussion about their development. The Government is considering the following:
- Development of regulatory controls to help reduce inhalation exposures to MEK and MIBK from certain products available to consumers, including paint or coating removers or strippers (for example, lacquer removers), adhesive removers, degreasers, paint or coating thinners, liquid paints, spray products (for example, spray paints) and wood lacquers.
- 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 July 15, 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.
Additional considerations
- Although 2,4-PD is not considered to be harmful to human health or to the environment at current levels of exposure, this substance is associated with effects of concern. Therefore, there may be a concern if exposures were to increase. For this reason, 2,4-PD may be considered in future initiatives to track its commercial status or identify new uses or exposures. In addition, this substance is being proposed for addition to the Watch List.
Where to find updates on risk management actions
Related resources
- Substances in the Ketones Group are 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 according to municipal or local guidelines.
- Visit Healthy home for information on chemical safety in and around the home, including on ketones (for consumers).
- Diacetyl, 2,3-PD, and acetoin have been identified as possible ingredients in vaping products (such as electronic cigarettes and vaping devices containing cannabis), which may represent an additional source of exposure to these substances. Vaping products that do not contain cannabis are being addressed through the Tobacco and Vaping Products Act. Cannabis products that may include these substances (such as vaping products or topicals) are being addressed through the cannabis legislative framework.
- 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 technical expertise of the CMP and Health Canada's Workplace Hazardous Products Program.
