New substances: risk assessment summary, new substances notification 18291
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 that 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
1,4-Cyclohexanedimethanol, polymer with (chloromethyl)oxirane (Chemical Abstracts Service Registry No. 71463-68-8) is a chemical of unknown or variable composition, complex reaction products, or biological material (UVCB) that can be classified as epoxy-terminated polyether.
Notified and potential activities
The substance is proposed to be manufactured in and/or imported into Canada in quantities greater than 10 000 kg/yr for use in industrial epoxy coatings. Potential uses may include consumer coatings.
Environmental fate and behaviour
Based on its physical and chemical properties, if released to the environment, the substance will tend to partition to water. The substance is not expected to be persistent in water because the substance will undergo hydrolysis under environmental conditions. The substance is not expected to bioaccumulate based on low predicted bioconcentration and bioaccumulation factors (<250 L/kg) for the substance and its hydrolysis products.
Ecological assessment
Based on the available hazard information on the substance and surrogate data on structurally related chemicals, the substance has moderate acute toxicity in fish and aquatic invertebrates (median lethal concentration (LC50) and median effective concentration (EC50) 1-100 mg/L), and low to moderate acute toxicity in algae (EC50 >1mg/L). The predicted hazard information on the hydrolysis product of the substance indicates that the hydrolysis product has low acute toxicity in fish, aquatic invertebrates, and algae (EC50 and LC50 >100 mg/L). Using the EC50 from the most sensitive organism (aquatic invertebrates) and by applying an assessment factor, the predicted no-effect concentration (PNEC) was calculated to be 100-1000 µg/L, which was used to estimate the ecological risk.
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 activities is expected to be mainly from transportation, formulation and use in industrial epoxy coatings by release of the substance to water at levels of 1-100 kg/d. Environmental exposure from potential activities may include manufacture and release of the substance to water at levels of 10-100 kg/d. The predicted environmental concentration (PEC) for notified and potential activities is estimated to be 1-100 µg/L. Other potential uses include adhesives, potting and encapsulating media, rigid foams and non-skid road surfacing. These uses would result in similar exposure scenarios as notified use.
Comparing the PEC with the PNEC, the ratio is less than 1, indicating that the substance is unlikely to cause ecological harm in Canada.
Human health assessment
Based on the available hazard information on the substance and surrogate data on structurally related chemicals, the substance has a moderate potential for acute toxicity by the oral route of exposure (median lethal dose 300-2000 mg/kg-bw) and a low potential for acute toxicity by the inhalation route of exposure (LC50 >5 mg/L). It has a moderate potential for subchronic and reproductive/developmental toxicity following repeat oral doses in mammalian test animals (no-observed-adverse-effect level (NOAEL) 250-1000 mg/kg-bw/d). It is a weak sensitizer (effective concentration >10%). It is mutagenic in vitro but not in vivo, and not clastogenic in vivo. Therefore, the substance is unlikely to cause genetic damage. The provisional tolerable daily intake (PTDI) was calculated to be 0.1 to 1 mg/kg-bw/d based on the NOAEL of the combined oral repeat dose and reproduction/developmental toxicity study in mammalian test animals of 250-1000 mg/kg-bw/d.
When used in industrial epoxy coatings, direct exposure of the general population is expected to low given that the substance will be chemically reacted into a polymer matrix during application and will not be available for uptake. Indirect exposure of the general population from environmental media such as water and air is expected to be low given that the substance will undergo hydrolysis in water and will not partition to air. If the substance is used in consumer coatings, an increased direct exposure potential by dermal contact may exist at levels of 0.1-1 mg/kg bw/event. Indirect exposure of the general population due to potential uses is expected to be low.
Based on the low potential for exposure for the notified use and based on a comparison of the PTDI to the estimated exposure for potential uses, 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
When used as notified or for other identified potential uses, the substance is not suspected to be harmful to human health or the environment according to the criteria under section 64 of CEPA.
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 workplace use.