New substances: risk assessment summary, new substances notification 20535
Official title: New Substances Notifications 19767 and 20535: Hexanoic acid, 3,5,5-trimethyl-, 2-ethylhexyl ester (Chemical Abstracts Service Registry Number 70969-70-9)
Regulatory decisions
Under the provisions for Substances and Activities New to Canada in Part 5 of the Canadian Environmental Protection Act, 1999 (CEPA), and pursuant to section 83 of the Act, the Minister of the Environment and the Minister of Health have assessed information in respect of the substance and determined that the substance is anticipated to enter the environment in a quantity or concentration or under conditions that constitute or may constitute a danger in Canada to human life or health.
In order to ensure that the substance does not cause harm to the Canadian environment or human health, its manufacture and import are authorized subject to conditions as described in Ministerial Condition No. 19767 published in the Canada Gazette Part I, Vol. 152, No. 48 on December 1, 2018, and Ministerial Condition No. 20535 published in the Canada Gazette Part I, Vol. 154, No. 44 on October 31, 2020.
Substance identity
The notified chemical is hexanoic acid, 3,5,5-trimethyl-, 2-ethylhexyl ester (Chemical Abstracts Service Registry NumberFootnote 1 70969-70-9).
Notified and potential uses
The substance is proposed to be imported into Canada in quantities up to 20 000 kg/yr for the notified use as an emollient additive for topical personal care products, including body lotions and hand cream, eye shadow, blush, lipstick, liquid concealer, facial cleansing oil, and hair removal wax products. No other uses are anticipated in Canada.
Environmental fate and behaviour
Based on its physical and chemical properties, if the substance is released to the environment, it will tend to partition to soil and sediment. The substance is not expected to be persistent in these compartments based on moderate biodegradation. The substance is not expected to bioaccumulate based on the high rate of metabolism expected due to the notified substance’s ester group. This is supported by low estimates of bioconcentration factor (<250 L/kg) from models that account for metabolism.
Environmental risk assessment
Based on the available hazard information, the substance has low acute toxicity to algae (no adverse effects observed in saturated solutions) and low chronic toxicity to aquatic invertebrates (no adverse effects observed in saturated solutions). A predicted no-effect concentration was not calculated given the low potential for hazard to the environment.
The notified activities in Canada were assessed to estimate the environmental exposure potential of the substance throughout its life cycle. Environmental exposure from the notified activity is expected to be mainly from consumer use and industrial processing by release of the substance to water. A predicted environmental concentration was not calculated due to the low potential for environmental ecotoxicity. No potential activities that could significantly increase environmental risks compared to those notified were identified.
Based on the low potential for ecotoxicity, the substance is unlikely to cause harm to the environment in Canada.
Human health risk assessment
Based on the available hazard information, the substance has a low acute toxicity by the oral route (median lethal dose > 2000 mg/kg body weight) and moderate subchronic toxicity following repeated oral doses in mammalian test animals (49-day no-observed-adverse-effect level (NOAEL) 30-300 mg/kg-bw/day). The substance has a moderate reproductive toxicity following repeated oral doses in mammalian test animals (NOAEL 30-300 mg/kg-bw/day). It is not a skin sensitizer (no positive reactions for sensitization) or an irritant to skin or eyes. It is not mutagenic in vitro. Therefore, the substance is unlikely to cause genetic damage.
When the notified substance is used as an emollient additive for topical personal care products, direct exposure of the general population is expected to be mainly by contact with the skin. Indirect exposure of the general population from environmental media such as drinking water is expected to be at low levels. No other potential uses that could significantly increase human health risks compared to the notified uses were identified.
Based on the dermal exposure from topical personal care products combined with the moderate reproductive toxicity, the substance is anticipated to be harmful to human health. These risks are associated with use of the substance in cosmetics.
The assumptions made in the assessment and the risk management measures applied are considered to be adequately protective for the general population as well as for subpopulations who may be more susceptible or highly exposed.
Other considerations
A similar substance, hexanoic acid, 2-ethyl-, 2-ethylhexyl ester (Chemical Abstracts Service Registry Number 7425-14-1), was found to meet one or more of the criteria set out in section 64 of the Act based on a screening assessment.
Assessment conclusion
The substance is suspected to constitute a danger to human health according to the criteria under paragraph 64 (c), but is not suspected to have a harmful effect on the environment according to the criteria under paragraph 64 (a) or (b) of the Act.
Due to the identified risk to human health related to the reproductive toxicity, a ministerial condition was issued to restrict the manner in which the notifier may manufacture or import the substance with conditions on its use in order to mitigate these potential risks. Ministerial Condition No. 19767 was published in the Canada Gazette Part I, Vol. 152, No. 48 on December 1, 2018. Ministerial Condition No. 20535 was published in the Canada Gazette Part I, Vol. 154, No. 44 on October 31, 2020.
A conclusion under CEPA, on this substance, is not relevant to, nor does it preclude an assessment against the hazard criteria for Workplace Hazardous Materials Information System that are specified in the Controlled Products Regulations or the Hazardous Products Regulations for products intended for the workplace.