October 8, 2024
Canada’s Proposed Plan of Priorities Includes Several Nanoscale Materials; Comments Are Due December 4, 2024
On October 5, 2024, the Minister of the Environment announced in the Canada Gazette publication of a proposed plan of priorities for the assessment of chemical substances. Under the 2023 amendments to the Canadian Environmental Protection Act, 1999 (CEPA), the Minister of the Environment and the Minister of Health are required to “develop, consult on and publish a plan with timelines” by June 2025. The proposed list of prioritized substances for assessment and the rationales for priorities include:
- Specific Substances:
- Nanoscale silver: Canada identified nanoscale silver under an initiative to ensure that nanomaterials currently in commerce in Canada undergo ecological and human health risk assessment. According to Canada, nanoscale forms of silver have not been explicitly considered in the assessments of existing substances conducted under CEPA. Nanoscale silver is used in a wide variety of commercial and consumer products, and advances in the ability to synthesize nanoscale silver have allowed for innovation for the impregnation of nanoscale silver “into common consumer products such as athletic clothing, bedding, cosmetics, and medical equipment, often leveraging the antimicrobial properties of the substance.” Canada notes that additionally, nanoscale silver “is useful in electrical and optical applications.” Canada states that there is evidence that nanoscale silver can be harmful to human health and the environment. Studies have reported associations between exposure to silver nanoparticles and reproductive/developmental effects, and there is also evidence of neurotoxicity. In addition, preliminary findings for nanoscale silver suggest high aquatic toxicity, particularly to planktonic and bacteria species. Nanoscale silver was found to be in commerce in Canada based on a 2015 information gathering initiative to determine the commercial status of nanomaterials. According to the work plan, Canada will begin assessment activities in fall 2024.
- Nanoscale zinc oxide: Canada identified nanoscale zinc oxide under an initiative to ensure that nanomaterials currently in commerce in Canada undergo ecological and human health risk assessment. Nanoscale forms of zinc oxide have not been explicitly considered in the assessments of existing substances conducted under CEPA. According to Canada, based on a 2015 information gathering initiative and an additional 2020 follow-up to determine the commercial status of certain nanomaterials, nanoscale zinc oxide was imported annually into Canada at a volume of 79,000 kilograms (kg), and was reported to be used in various consumer products, including some intended for use by or for children (e.g., toys, sunscreen lotions), food packaging, drugs, and personal care and cosmetics. Canada states that there is evidence that nanoscale zinc oxide can be harmful to human health and the environment and that nanoscale zine oxide can affect aquatic organisms due to nanoparticle effects and release of the zinc ion. There is a concern for reproductive/developmental toxicity following exposure to nanoscale zinc oxide, and potential hazard resulting from repeated dose oral and inhalation exposure is moderate. Zinc oxide nanoparticles may exert genotoxic effects in mammalian cells. According to the work plan, Canada will begin assessment activities on nanoscale zinc oxide in summer 2026.
- Nanoscale silver: Canada identified nanoscale silver under an initiative to ensure that nanomaterials currently in commerce in Canada undergo ecological and human health risk assessment. According to Canada, nanoscale forms of silver have not been explicitly considered in the assessments of existing substances conducted under CEPA. Nanoscale silver is used in a wide variety of commercial and consumer products, and advances in the ability to synthesize nanoscale silver have allowed for innovation for the impregnation of nanoscale silver “into common consumer products such as athletic clothing, bedding, cosmetics, and medical equipment, often leveraging the antimicrobial properties of the substance.” Canada notes that additionally, nanoscale silver “is useful in electrical and optical applications.” Canada states that there is evidence that nanoscale silver can be harmful to human health and the environment. Studies have reported associations between exposure to silver nanoparticles and reproductive/developmental effects, and there is also evidence of neurotoxicity. In addition, preliminary findings for nanoscale silver suggest high aquatic toxicity, particularly to planktonic and bacteria species. Nanoscale silver was found to be in commerce in Canada based on a 2015 information gathering initiative to determine the commercial status of nanomaterials. According to the work plan, Canada will begin assessment activities in fall 2024.
- Certain Substances within the Following Groups:
- Nanoscale forms of nickel oxide: Canada identified nanoscale nickel oxide under an initiative to ensure that nanomaterials currently in commerce in Canada undergo ecological and human health risk assessment. Nanoscale forms of nickel oxide have not been explicitly considered in the assessments of existing substances conducted under CEPA. According to Canada, nanoscale nickel oxide is used in commercial and consumer products for energy storage, in magnetic materials, and in thermoelectric, catalytic, and photocatalytic applications. Canada states that nanoscale nickel oxide is known to cause oxidative stress and toxicity to organisms in the environment. Non-nanoscale nickel oxide was assessed in 1994 and added to CEPA Schedule 1 along with other nickel compounds due to its potential for human carcinogenicity. Canada notes that nanoscale nickel oxide was found to be in commerce in Canada based on a 2015 information gathering initiative to determine the commercial status of nanomaterials. In addition, the increasing use of nanoscale nickel oxide means that there may be greater potential for environmental and human exposure. The proposed approach is to conduct risk characterization of nanoscale nickel oxide to determine whether there is need for specific risk management measures for the nanoscale forms. According to the work plan, Canada will begin assessment activities on substances within the group as early as fall 2024 while it will begin assessment activities on others in summer 2026.
- Nanoscale forms of titanium dioxide: Canada identified nanoscale titanium dioxide under an initiative to ensure that nanomaterials currently in commerce in Canada undergo ecological and human health risk assessment. Nanoscale forms of titanium dioxide have not been explicitly considered in the assessments of existing substances conducted under CEPA. Canada states that based on a 2015 information gathering initiative and an additional 2020 follow-up to determine the commercial status of certain nanomaterials, nanoscale titanium dioxide was found to be imported into Canada at a high volume in 2014 (>600,000 kg) and was reported to be used in various consumer products, including self-care products, paints and coatings, adhesives, and sealants. According to Canada, nanoscale titanium dioxide can be photoactive in the aquatic environment causing oxidative stress and potential toxicity to aquatic organisms. The International Agency for Research on Cancer (IARC) has classified titanium dioxide as a Group 2B carcinogen (possibly carcinogenic to humans). Nanoscale titanium dioxide may have negative genotoxic neurotoxicological, cardiovascular, and reproductive effects. It also has been shown to cause pulmonary damage/inflammation following inhalation exposure. According to the work plan, Canada will begin assessment activities on substances within the group in summer 2026.
- Nanoscale forms of nickel oxide: Canada identified nanoscale nickel oxide under an initiative to ensure that nanomaterials currently in commerce in Canada undergo ecological and human health risk assessment. Nanoscale forms of nickel oxide have not been explicitly considered in the assessments of existing substances conducted under CEPA. According to Canada, nanoscale nickel oxide is used in commercial and consumer products for energy storage, in magnetic materials, and in thermoelectric, catalytic, and photocatalytic applications. Canada states that nanoscale nickel oxide is known to cause oxidative stress and toxicity to organisms in the environment. Non-nanoscale nickel oxide was assessed in 1994 and added to CEPA Schedule 1 along with other nickel compounds due to its potential for human carcinogenicity. Canada notes that nanoscale nickel oxide was found to be in commerce in Canada based on a 2015 information gathering initiative to determine the commercial status of nanomaterials. In addition, the increasing use of nanoscale nickel oxide means that there may be greater potential for environmental and human exposure. The proposed approach is to conduct risk characterization of nanoscale nickel oxide to determine whether there is need for specific risk management measures for the nanoscale forms. According to the work plan, Canada will begin assessment activities on substances within the group as early as fall 2024 while it will begin assessment activities on others in summer 2026.
Comments are due December 4, 2024.