New substances: risk assessment summary, new substances notification 20274
Official title: New Substances Notification 20274: Hexanedioic acid, polymer with α-hydro-ω-hydroxypoly[oxy(methyl-1,2-ethanediyl)], 1,1'-methylenebis[4-isocyanatobenzene],2,2'-oxybis[ethanol] and and oxybis[alkanol] (Confidential Accession Number 19482-0)
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 hexanedioic acid, polymer with α-hydro-ω-hydroxypoly[oxy(methyl-1,2-ethanediyl)], 1,1'-methylenebis[4-isocyanatobenzene], 2,2'-oxybis[ethanol] and oxybis[alkanol] (Confidential Accession No. 19482-0). The substance does not meet the Reduced Regulatory Requirements criteria according to the New Substances Notification Regulations (Chemicals and Polymers) because it contains aromatic isocyanates.
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 as a component in industrial adhesives. Potential uses may include industrial coatings and polyurethane foams.
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 sediment or soil. The substance is expected to be persistent in soil and sediment because it reacts with water to form high molecular weight, insoluble complexes that are resistant to degradation. The substance is not expected to bioaccumulate based on its low water extractability and high molecular weight, which will limit its ability to cross biological membranes.
Ecological assessment
Based on the available hazard information, the substance is expected to have low acute toxicity to fish (no adverse effects observed in saturated solutions). Therefore, a predicted no-effect concentration was not calculated given the low potential for ecological hazard.
The notified and other potential 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 not expected as the substance will be chemically reacted to form a stable matrix once cured and will be highly removed during wastewater treatment. For potential activities such as use in industrial coatings and polyurethane foam, environmental exposure is expected to be similar to that of the notified use. A predicted environmental concentration was not calculated due to the low potential for environmental exposure and low ecotoxicity.
Based on the low potential for ecotoxicity and environmental exposure, the substance is unlikely to cause ecological harm in Canada.
Human health 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). As an isocyanate polymer, the substance is expected to be a sensitizer.
When the notified substance is used as a component in industrial adhesives consumers may come into contact with end-use products containing the substance; however, direct exposure is not expected because the substance will be chemically reacted into a stable matrix once the product is cured and will be unavailable for uptake. Indirect exposure of the general population from environmental media such as drinking water and air is not expected given the low potential for environmental release. 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.
Assessment conclusion
The substance 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 Hazardous Products Regulations for products intended for the workplace.