New substances: risk assessment summary, new substances notification 19641
Official title: New Substances Notification 19641: Zinc, neodecanoate alkanoate complexes (Confidential Accession Number 19156-4)
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 zinc, neodecanoate alkanoate complexes (Confidential Accession No. 19156-4), and is considered a substance of unknown or variable composition, complex reaction products or biological materials (UVCB).
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 an industrial processing aid. 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, soil and sediment. The substance is not expected to be persistent in these compartments based on its moderate to very high ready biodegradability (>30% over 28 days). Upon biodegradation, the zinc ion of the substance will be released and will tend to partition to water, soil and sediment. The zinc ion is expected to be persistent in these compartments because it cannot degrade any further. The substance is not expected to bioaccumulate based on its high molecular weight and low to moderate water solubility (0.01-1000 mg/L) which will limit its ability to cross biological membranes.
Ecological assessment
Based on the available hazard information on the substance and surrogate data on structurally related chemicals, the substance is expected to have low acute toxicity in fish and aquatic invertebrates (no adverse effects observed in saturated solutions; median effective loading rate (EL50) >100 mg/L) and moderate acute toxicity in algae (median effective concentration and EL50 1-100 mg/L). The toxicity of the zinc moiety was also considered. Ecotoxicity studies from scientific literature suggest that zinc is expected to have high chronic toxicity in fish, aquatic invertebrates and algae. The predicted no-effect concentration (PNEC) was determined to be 7.5 µg/L based on the water quality guidelines of the British Columbia Ministry of Environment, Lands and ParksFootnote 1 [PDF], 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 negligible given that residual product in transportation vessels would be reprocessed or reused and the substance will be consumed during use, with any excess substance encapsulated within a stable matrix and unavailable for release. For potential activities such as manufacturing, environmental exposure is expected to be mainly from release of the substance to water resulting in a predicted environmental concentration (PEC) between 0.01 to 0.1 µg/L.
Based on the low potential for environmental exposure when used as notified, and comparing the PEC for potential activities with the PNEC resulting in a ratio less than 1, 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). It is not mutagenic in vitro. Therefore, the substance is unlikely to cause genetic damage.
When the notified substance is used as an industrial product treatment, direct exposure of the general population is expected to be negligible due to the industrial nature of the use. 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 which could significantly increase human health risks compared to the notified uses were identified.
Based on the low potential for exposure and lack of identified human health hazards, 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.