New substances: risk assessment summary, new substances notification 20222
Official title: New Substances Notification 20222: Sulfonic acids, branched alkane hydroxy and branched alkene, sodium salts (Confidential Accession Number 19435-3)
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 determined that the substance is 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.
In order to ensure that the substance does not cause harm to the Canadian environment or human health, its manufacture and import are authorized subject to conditions as described in Ministerial Condition No. 20222, published in the Canada Gazette Part I, Vol. 154, No. 23 on June 6, 2020.
Substance identity
The notified chemical is sulfonic acids, branched alkane hydroxy and branched alkene, sodium salts (Confidential Accession No. 19435-3), 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 in oil recovery applications. Potential uses may include shale gas extraction processes, laundry detergents, dishwashing products, household cleaning products, personal care products, textile, leather, and cosmetic industries and the manufacturing and formulation of various goods.
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. The substance is not expected to be persistent based on its inherent biodegradation (30-60% over 28 days). The substance is not expected to bioaccumulate based on its low predicted bioaccumulation and bioconcentration factors (<250 L/kg).
Ecological assessment
Based on the available hazard information, the substance has low acute toxicity to saltwater fish and aquatic invertebrates (median lethal loading rate >100 mg/L), moderate acute toxicity to freshwater aquatic invertebrates (median effective concentration 1 -100 mg/L), moderate to high acute toxicity to freshwater fish (median lethal concentration (LC50) <1 to 100 mg/L) and low chronic toxicity to freshwater algae (10% effective concentration >10 mg/L). Using the LC50 from the most sensitive organism (fish) and by applying an assessment factor of 20 to account for acute to chronic extrapolation and mode of action, the predicted no effect concentration (PNEC) was calculated to be in the range of 0.001-0.01 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 cleaning of transportation vessels (should this occur in Canada) 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 manufacturing or formulation, environmental exposure is expected to be similar to that of the notified use.
Based on the potential for environmental exposure combined with high acute aquatic toxicity, the substance is anticipated to cause ecological harm in Canada. The risks have been identified with release of the substance to water when used in manufacturing, formulation or consumer products.
Human health assessment
Based on the available hazard information, the substance is expected to have low acute toxicity by the oral route (median lethal dose (LD50) >2000 mg/kg body weight), high acute toxicity by the dermal route (LD50 200-1000 mg/kg body weight) and moderate chronic toxicity following repeated oral doses in mammalian test animals (2-years no-observed-adverse-effect level (NOAEL) >100 mg/kg-bw/day). The substance is expected to have a high developmental toxicity following repeated oral doses in mammalian test animals (NOAEL <30 mg/kg-bw/day). It is not expected to be a skin sensitizer (0-8% response (guinea pig maximization test)). It is not expected to be mutagenic in vitro or in vivo and is not clastogenic in vitro. Therefore, the substance is unlikely to cause genetic damage. The provisional tolerable daily intake (PTDI) was calculated to be in the range of 0.01-0.1 mg/kg-bw/day based on the NOAEL of the oral developmental toxicity study in mammalian test animals. The PTDI is the estimated level of long-term exposure without risk of adverse health effects.
When the notified substance is used in oilfield applications, 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 conservatively estimated to be at levels in the range of 0.0001-0.001 mg/kg bw/day. Potential uses of the substance include consumer activities, where direct exposure of the general population is expected to be by contact with the skin at levels in the range of 0.01-0.1 mg/kg bw/day, inhalation at levels in the range of 0.00001-0.0001 mg/kg bw/day or ingestion at levels in the range of 0.001-0.01 mg/kg bw/day. Indirect exposure of the general population from environmental media such as drinking water is expected to be at levels in the range of 0.0001-0.01 mg/kg bw/day.
Because the estimated human exposures are less than the PTDI, meaning at levels that do not pose a concern, 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 suspected to be harmful to the environment according to the criteria under paragraph 64(a), but not according to the criteria under paragraph 64(b) or to human health under paragraph (c) of the Act.
Due to the identified risk to the environment related to the aquatic toxicity, a ministerial condition was issued to restrict the manner in which the notifier may manufacture or import the substance with conditions on its use, handling and disposal in order to mitigate these potential risks. Ministerial Condition No. 20222 was published in the Canada Gazette Part I, Vol. 154, No. 23 on June 6, 2020.
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.