New substances: risk assessment summary, new substances notification 21218
Official title: New Substances Notification 21218: Isocyanic acid, polymethylenepolyphenylene ester, polymer with α-hydro-ω-hydroxypoly[oxy(methyl-1,2-ethanediyl)] ether with 2-alkyl-2-(hydroxymethyl)-1,3-propanediol (3:1), 2-hydroxyethyl methacrylate-blocked (Confidential Accession Number 19639-7)
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 have determined that it is not anticipated to enter the environment in a quantity or concentration or under conditions that have or may have an immediate or long term harmful effect on the environment or its biological diversity, constitute or may constitute a danger to the environment on which life depends, or constitute or may constitute a danger in Canada to human life or health.
Substance identity
The notified polymer is isocyanic acid, polymethylenepolyphenylene ester, polymer with α-hydro-ω-hydroxypoly[oxy(methyl-1,2-ethanediyl)] ether with 2-alkyl-2-(hydroxymethyl)-1,3-propanediol (3:1), 2-hydroxyethyl methacrylate-blocked (Confidential Accession Number 19639-7). The substance does not meet the Reduced Regulatory Requirements criteria according to the New Substances Notification Regulations (Chemicals and Polymers) because its number average des molecular weight is less than 1000 daltons. In addition, it contains methacrylate groups.
Notified and potential uses
The substance is proposed to be imported into Canada in quantities greater than 10 000 kg/yr for the notified use in the manufacture of automotive body and marine craft parts. 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 expected to be persistent in these compartments based on the expected low biodegradation potential and because the functional groups susceptible to hydrolysis are embedded within the polymer matrix. The substance is not expected to bioaccumulate based on its low predicted bioaccumulation and bioconcentration factors (< 250 L/kg) and its low water extractability (< 2%), which will limit its bioavailability.
Environmental risk assessment
Based on the available hazard information and the low water extractability (< 2%), the substance is expected to have low acute toxicity to fish (median lethal concentration > 100 mg/L). 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 by release of the substance to water at low rates. A predicted environmental concentration was not calculated due to the low potential for environmental exposure and ecotoxicity. No potential activities that could significantly increase environmental risks compared to those notified were identified.
Based on the low potential for environmental exposure and 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 is expected to have a low acute toxicity by the oral route (median lethal dose > 2000 mg/kg body weight). The substance also contains structural features which are associated with skin sensitization.
When the notified substance is used in the manufacture of automotive body and marine craft parts, direct exposure of the general population is not expected due to the industrial nature of the use. Consumers may come into contact with end-use composite products; however, direct exposure is not expected as the substance will be consumed during processing and trapped within a stable matrix from which it will not be released. Indirect exposure of the general population from environmental media is not expected given the specialized industrial use of the substance, which results in little or no release to the environment. No potential uses that could significantly increase human health risks compared to the notified uses were identified.
Based on the low potential for exposure, the substance is not likely to pose a significant health risk to the general population, and is therefore unlikely to be harmful to human health.
The assumptions made in the assessment are considered to be adequately protective for the general population as well as for subpopulations who may be more susceptible or highly exposed.
Assessment conclusion
When the substance is used as notified, it is not expected to be harmful to human health or the environment according to the criteria under section 64 of the Act.
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.