New substances: risk assessment summary, new substances notification 19855
Official title: New Substances Notification No. 19855: Morpholine, 2-hydroxy-1,2,3-propanetricarboxylate (Chemical Abstracts Service No. 62038-11-3)
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 chemical is morpholine, 2-hydroxy-1,2,3-propanetricarboxylate (Chemical Abstracts Service No.Footnote 1 62038-11-3).
Notified and potential activities
The substance is proposed to be imported into Canada in quantities greater than 10 000 kg/yr for the notified use as a water treatment chemical in pulp and paper plants. 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 water, where it will dissociate to form morpholine and citrate. The substance and its components are not expected to be persistent in this compartment based on very high ready biodegradation (>85% over 28 days). The substance and its components are not expected to bioaccumulate based on their very low octanol-water partition coefficients (log Kow ≤0) and very high biodegradation potential, and a low measured bioconcentration factor (<250 L/kg over 6 weeks) for morpholine in fish.
Ecological assessment
Based on the available hazard information, the substance is expected to have moderate acute and chronic toxicity in aquatic invertebrates (acute median effective concentration (EC50) 1-100 mg/L; chronic no-observed-effect concentration (NOEC) 0.1-10 mg/L), low acute and chronic toxicity in fish (acute median lethal concentration > 100 mg/L; chronic NOEC >10 mg/L), and moderate acute toxicity in algae (EC50 1-100 mg/L). Using the chronic NOEC from the most sensitive organism (aquatic invertebrates) and by applying an assessment factor of 2 to account for species sensitivity variation, the predicted no-effect concentration (PNEC) was calculated to be in the range of 1-10 mg/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 activity is expected to be mainly from use in pulp and paper plants by release of the substance to water resulting in a predicted environmental concentration (PEC) in the range of 0.01-0.1 mg/L. For potential activities such as industrial manufacturing, environmental exposure is expected to be mainly by release of the substance to water resulting in a PEC in the range of 0.1-1 mg/L. For potential activities such as blending, environmental exposure is expected to be at levels that do not pose a concern, similar to that of the notified use.
Comparing the PEC with the PNEC, the ratio is less than 1. This, along with other lines of evidence including environmental fate, hazard, and exposure, indicates that the substance is unlikely to cause ecological harm in Canada.
Human health 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 is expected to have low acute toxicity by dermal and inhalation routes. It is expected to have low subchronic toxicity following repeated inhalation doses in mammalian test animals. The substance is not mutagenic in vitro and is not expected to be clastogenic in vitro or in vivo. Therefore, the substance is unlikely to cause genetic damage.
When the notified substance is used as a water treatment chemical in pulp and paper plants, direct exposure of the general population is not expected due to the industrial nature of the use. Indirect exposure of the general population from environmental media such as drinking water is not expected given the low potentials for environmental release and the fact that the substance will dissociate in water and the substance and its components have very high biodegradation rates.
Potential activities include manufacture and blending of the substance, where direct and indirect exposure of the general population is expected to be at levels that do not pose a concern, similar to that of the notified use. No potential uses which could significantly increase human health risks compared to the notified uses were identified.
Based on the low toxicity and 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
When the substance is used as notified or for other identified potential activities, 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 Hazardous Products Regulations for products intended for the workplace.