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 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.
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.
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.
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.
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.
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.
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.