Esters Group - information sheet

Publications summarized:

• Draft Screening Assessment for the Esters Group (published on March 19, 2022 for a 60-day public comment period ending on May 18, 2022)
• Risk Management Scope for Methyl Acetate (Acetic acid, methyl ester) (Published on March 19, 2022 for a 60-day public comment period ending on May 18, 2022). Risk management is proposed.
• Associated notice: Canada Gazette, Part I: Vol. 156, No. 12 – March 19, 2022

On this page

• Overview
• About these substances
• Human and ecological exposures
• Key health and ecological effects (hazard)
• Consideration of vulnerable populations
• Risk assessment outcomes
  • Proposed screening assessment conclusions
• Preventive actions and risk reduction
  • Additional considerations
  • Where to find updates on risk management actions
• Related resources

Overview

• The Government of Canada conducts risk assessments of substances under the Canadian Environmental Protection Act, 1999 (CEPA 1999) 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 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 ecological hazard and exposure potentials of the 14 substances in the Esters Group were classified using the Ecological Risk Classification of Organic Substances (ERC) Approach.
• The Government is proposing that methyl acetate may be harmful to human health, but not to the environment, at levels of exposure considered in the assessment. This is due to potential inhalation exposure of Canadians to methyl acetate from the use of certain aerosol adhesives and paint stripper or remover products (referred to as paint removers). Methyl acetate may be associated with developmental effects.
  • To address human health concerns, the Government is considering measures to help reduce consumer exposure to methyl acetate from the use of aerosol adhesives and paint remover products.
• Certain substances in this group are considered to be low hazard while some may be associated with ecological effects or effects on human health, including developmental or reproductive effects.
• The Government is also proposing that the other 13 substances in the Esters Group are not harmful to human health and that none of the substances in this group are harmful to the environment, at levels considered in the assessment.

About these substances

• The summary of publications for the Esters Group  includes details on the substance names and CAS Registry Numbers (RNs).
• The screening assessment focused on 14 of 16 substances referred to collectively as the Esters Group under the third phase of the Chemicals Management Plan (CMP). These substances are methyl acetate, triacetin, methyl hexanoate, propyl acetate, isobutyl acetate, methyl dodecanoate, docusate sodium, methyl butanoate, dimethyl glutarate, tetradecyl tetradecanoate, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, texanol, C14-22 monoglycerides, and 2-methoxypropyl acetate.
• Two other substances in the Esters Group (CAS RNs 111-55-7 and 122-79-2) were determined to be of low concern to both human health and the environment through other approaches. Conclusions for these substances are provided in the Final 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.
• Some of the substances in the Esters Group are naturally occurring in some fruits or plants.
• According to information gathered by the Government, several of these substances are used primarily as solvents, plasticizers, or skin-conditioning agents in Canada.
• Most of the substances in this group are used in a range of industrial and commercial products, as well as in products available to consumers, including cosmetics, natural health products, prescription and/or non-prescription drugs, as well as in paint, adhesives, air fresheners, paint removers, fiberglass repair, and concrete crack repair products.
• Some of these substances may also be used as food flavouring agents. Triacetin and docusate sodium are on the Lists of Permitted Food Additives in Canada, and C14-22 monoglycerides is included in the listings for 2 approved food additives in Canada (monoglycerides or mono- and di-glycerides, which are also permitted food additives in Canada).

Human and ecological exposures

• Exposure to substances in the Esters Group may occur from inhalation (breathing in), skin contact or oral ingestion. Canadians may be exposed to:
  • Methyl acetate due to its natural occurrence in food, from indoor air, and from the use of products containing the substance, including nail products, cleaning products, automotive products, adhesives, adhesive removers, lubricants, paint strippers or removers, and floor coatings.
  • Methyl hexanoate and methyl butanoate due to their presence in indoor air, or from their potential use as food flavouring agents; methyl hexanoate is also found in nail products (cosmetics).
  • 2-Methoxypropyl acetate due to its possible presence in the environment (for example, air and water), and possibly from the use of products such as cosmetics, aerosol paints, or putty fillers.
  • 2,2,4-Trimethyl-1,3-pentanediol diisobutyrate due to its presence in indoor air and from the use of products, such as nail products, cosmetic adhesives, natural health products, aerosol primer, pool paint, hobby paints, fiberglass repair and concrete crack repair products, baby bottles, and plastic toys.
  • Docusate sodium through its use as a permitted food additive, and from the use of products such as cosmetics, natural health products, prescription and/or non-prescription drugs, cleaning products, wallpaper paste activator, and hardener products.
• Canadians may be exposed to the other 8 substances in this group (triacetin, propyl acetate, isobutyl acetate, methyl docecanoate, dimethyl glutarate, tetradecyl tetradecanoate, texanol, and C14-22 monoglycerides) from food as well as their use in various products available to consumers, including cosmetics, natural health products, and prescription and/or non-prescription drugs. Estimates of human exposure for these 8 substances were not derived due to their low hazard potential.
• According to information considered under the ERC approach, propyl acetate and isobutyl acetate were identified as having a high ecological exposure potential on the basis of relatively large import quantities and long half lives in air. The remaining substances were identified as having a low ecological exposure potential.

Key health and ecological effects (hazard)

• To inform the health effects characterization in the screening assessment, international reports of data on these substances were considered, including reviews by the European Union, Organisation for Economic Co-operation and Development, and the United States Environmental Protection Agency.
• There were limited health effects data for some of the substances; therefore, a comparative approach using data from metabolites (break down products) or data from similar chemicals, called read-across, was used for assessing potential health effects.
• For methyl acetate, methyl hexanoate, and methyl butanoate, developmental effects were the critical effects identified for characterizing the risk to human health, due to the breakdown of these substances to form methanol, which is being assessed as part of the Alcohols Group under the CMP.
• 2-Methoxypropyl acetate may damage the unborn child according to the harmonized classification and labelling approved by the European Union. The critical effect considered in the screening assessment of 2-methoxypropyl acetate was developmental toxicity.
• Other critical effects included potential reproductive effects for 2,2,4-trimethyl-1,3-pentanediol diisobutyrate and for docusate sodium, general systemic toxicity and developmental effects.
• The 8 other substances were considered to be of low hazard potential for the human health assessment.
• According to information considered under the ERC approach:
  • 2,2,4-Trimethyl-1,3-pentanediol diisobutyrate was identified as having a moderate ecological hazard potential on the basis of its potential to bioaccumulate and cause adverse effects in aquatic food webs.
  • Docusate sodium was also classified as having a moderate ecological hazard potential on the basis of its overall ecotoxicity.
  • The remaining 12 substances were identified as having a low ecological hazard potential.

Consideration of vulnerable populations

• There are groups of individuals within the Canadian population who, due to greater susceptibility or greater exposure, may be more likely to experience adverse health effects from exposure to substances.
• Certain subpopulations are routinely considered throughout the screening assessment process. For example, infants and children may be considered more vulnerable because their behaviours, physiology or development stage may result in higher exposures or increased susceptibility to the effects of a substance. These subpopulations were taken into account in the risk assessment outcomes for certain substances in the Esters Group, where data was available.

Risk assessment outcomes

• It was determined that methyl acetate may pose a risk to human health from potential inhalation exposure through use of aerosol adhesives and paint removers containing this substance. This was based upon a comparison of levels to which Canadians may be exposed to methyl acetate and levels associated with critical health effects. Other sources of exposure were not identified as a concern.
• Eight of the 14 substances in the Esters Group (triacetin, propyl acetate, isobutyl acetate, methyl docecanoate, dimethyl glutarate, tetradecyl tetradecanoate, texanol, and C14-22 monoglycerides) were considered to be of low hazard potential; therefore, the risk to human health for these substances is considered to be low.
• For 5 of the 14 substances in the Esters Group (methyl hexanoate; methyl butanoate; 2-methoxypropyl acetate; 2,2,4-trimethyl-1,3-pentanediol diisobutyrate; and docusate sodium) it was determined that there is a low risk of harm to human health. This was based upon a comparison of levels to which Canadians may be exposed to each of these substances and levels associated with critical health effects. 
• Based upon the outcome of the ERC approach, these 14 substances are considered unlikely to be causing ecological harm.

Proposed screening assessment conclusions

• The Government is proposing that methyl acetate may be harmful to human health, but that the other 13 substances in the Esters Group are not harmful to human health, at levels of exposure considered in the assessment.
• The Government is also proposing that these 14 substances are not entering the environment at levels that are harmful to the environment.
• It is proposed that methyl acetate meets 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

• If the proposed conclusion is confirmed in the final screening assessment, the Government will consider adding methyl acetate to Schedule 1 to CEPA 1999, also called the List of Toxic Substances. 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 scope aims to inform stakeholders of proposed risk management options and initiate discussion about their development. The Government will consider the following action to address human health concerns:
  • Taking measures to help reduce consumer exposure to methyl acetate from the use of aerosol adhesives and paint remover products.
• Information is being sought by the Government to inform risk management decision-making. Details can be found in the proposed risk management scope, including where to send information during the public comment period, ending May 18, 2022.

Additional considerations

• While 2-methoxypropyl acetate is not considered to be harmful to human health or to the environment at levels of exposure considered in the assessment, this substance is considered to have a health effect of concern based on its potential developmental effects. Therefore, there may be a potential risk if exposures to this substance were to increase.
• For this reason, the Government is considering follow-up activities to track changes in exposure and/or commercial use patterns for 2-methoxypropyl acetate.
• Stakeholders are encouraged to provide any information pertaining to this substance that may help inform the choice of follow-up activity, during the 60-day public comment period on the assessment. This could include information on new or planned import, manufacture or use of the substance.

Where to find updates on risk management actions

• Additional information on the risk management of substances addressed under the CMP is available.
• 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

• Substances in the Esters Group 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.
• Visit Do it for a Healthy Home for information on chemical safety in and around the home, including on methyl acetate (for consumers).
• Methyl acetate and isobutyl acetate have been identified as possible ingredients in vaping products, which may represent an additional source of exposure to these substances. Vaping products (such as electronic cigarettes and vaping devices containing cannabis) are being addressed through separate legislative frameworks.
• The screening assessment focused on potential risks of 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.