Selected C3-C5 Alcohols Group - information sheet
Publications summarized:
- Final Assessment for Selected C3-C5 Alcohols Group(published on October 25, 2025). Public comments received on the draft assessment were considered and a summary of the comments with Government responses was published.
- Associated notice: Canada Gazette, Part I: Vol. 161, No. 47 - November 22, 2025.
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 the 6 substances in the Selected C3-C5 Alcohols Group were classified using the Ecological Risk Classification of Organic Substances (ERC) Approach.
- The Government concluded that all 6 substances in the Selected C3-C5 Alcohols Group are not harmful to human health or to the environment at levels of exposure considered in the assessment.
About these substances
- The assessment focuses on 6 substances, referred to collectively as the Selected C3-C5 Alcohols Group under the Chemicals Management Plan (CMP). The substances are 1-propanol, 2-propanol, propylene glycol, 1-pentanol, isobutanol, and tert-butanol.
- Details on the substance names and CAS RNs are found in the summary of publications section of the Selected C3-C5 Alcohols Group web page.
- 1-Propanol, 2-propanol, propylene glycol, 1-pentanol, and isobutanol occur naturally in the environment, while tert-butanol does not.
- According to information gathered by the Government, these substances (except propylene glycol) are mainly used in Canada in paints and coatings. Additional uses include in ink, toners and colourants; cleaning and furnishing care (1-propanol, 2-propanol and isobutanol); automotive, aircraft and transportation (2-propanol and 1-pentanol); self-care products; adhesives and sealants; and oil and natural gas extraction (2-propanol).
- Substances in the Selected C3-C5 Alcohols Group may be used in cosmetics (1-propanol, 2-propanol, propylene glycol and tert-butanol), as food additives (2-propanol and propylene glycol), as food flavouring agents (1-propanol, 2-propanol, 1-pentanol, and isobutanol), as components in the manufacture of food packaging materials (all), as incidental additives (tert-butanol), as medicinal or non-medicinal ingredients in drugs (all except 1-pentanol) including self-care products (1-propanol, 2-propanol, propylene glycol, and tert-butanol), as active ingredients in pest control products (2-propanol and propylene glycol), as formulants (not an active ingredient) in pest control products (all except 1-pentanol), and in other products available to consumers.
Human and ecological exposures
- Since 1-propanol, 2-propanol, propylene glycol, and 1-pentanol are considered to be of low hazard potential, their human health exposure estimates were not developed for the assessment.
- The assessment indicated that people in Canada may be exposed to isobutanol from environmental sources (for example, air and drinking water), food, and from the use of products available to consumers (paints and coatings).
- People in Canada may be exposed to tert-butanol from environmental sources and from the use of various products available to consumers, such as cosmetics and drugs including self-care products.
- According to the information considered under the ERC Approach, 5 substances in the Selected C3-C5 Alcohols Group were identified as having low ecological exposure potential. tert-Butanol, however, was classified as having a high ecological exposure potential based on a critically long half-life in air (ability to stay in the air for a long-time) in combination with high reported use quantities.
Key health and ecological effects (hazard)
- To help inform the health effects characterization in the assessment, international and national reports on some substances in the Selected C3-C5 Alcohols Group were considered, among other sources of information. This included assessments by the European Chemicals Agency, the Organisation for Economic Co-operation and Development (OECD), the United States National Toxicology Program and the United States Environmental Protection Agency, among others.
- There were limited health effects (hazard) data for 1-propanol, 1-pentanol and isobutanol; therefore, a comparative approach using similar chemicals, called read-across, was used for assessing potential health effects.
- The general principles outlined in the Science approach document for substances with low human health hazard potential were taken into consideration for this health effects assessment. 1-Propanol, 2-propanol, propylene glycol, and 1-pentanol are considered to have a low health hazard potential.
- Based on laboratory studies, the critical effects used to characterize human health risk to isobutanol were neurodevelopmental effects.
- Based on laboratory studies, the critical effects used to characterize human health risk to tert-butanol were effects on the kidneys and thyroid cancer.
- According to information considered under the ERC Approach, all 6 substances in the Selected C3-C5 Alcohols were identified as having a 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.
- In addition, people living near industrial releases were considered in the assessment of isobutanol and tert-butanol.
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.
- On the basis of the information presented in the assessment, the risk to human health from 1-propanol, 2-propanol, propylene glycol, and 1-pentanol is low.
- Based upon a comparison of levels to which people in Canada may be exposed to isobutanol and tert-butanol and levels associated with health effects, it was determined that the risk to human health from these substances is also low.
- Based upon the outcome of the ERC Approach, these 6 substances are considered unlikely to be causing ecological harm at current levels of exposures considered in the assessment.
Proposed screening assessment conclusions
- The Government concluded that the 6 substances in the Selected C3-C5 Alcohols Group are not harmful to human health at levels of exposure considered in the assessment, and that these 6 substances are not entering the environment at levels that are harmful.
Related resources
- Substances in the Selected C3-C5 Alcohols 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. Use the Substances Search tool to find substances that are referenced in certain legislative or regulatory instruments or on Government of Canada websites.
- 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.
