On November 22, 2025, Environment and Climate Change Canada and Health Canada issued final assessment conclusions for two substances in the "Decenes Group" under Section 68 of the Canadian Environmental Protection Act (CEPA). The assessment concluded that neither substance poses a significant risk to the ecological environment. However, under specific usage scenarios (such as firearm maintenance sprays), they may cause pathological damage to the nasal cavity and lungs. Therefore, they were deemed to meet the criteria of CEPA Section 64(c) as "potentially posing a danger to human health" and will be subject to further risk management measures.
Two Substances in the Decenes Group
|
CAS RN |
DSL name |
Common name (abbreviation) |
|
68649-11-6 |
1-Decene, dimer, hydrogenated |
Hydrogenated didecene |
|
68649-12-7 |
1-Decene, tetramer, mixed with 1-decene trimer, hydrogenated |
Hydrogenated trimer and tetramer of decene (HTTD) |
These substances are primarily used in lubricants, greases, cosmetics, and automotive care products, and are also present in cleaning/lubricating/protecting (CLP) spray products for firearm maintenance. They are imported and produced domestically in Canada on a significant scale.
Key Conclusions
- Ecological Risk: Using the Ecological Risk Classification (ERC) model for organic substances, which integrates hazard and exposure indicators, the conclusion is "Low Concern."
- Health Risk: No significant concerns were identified for oral and dermal exposure. However, under inhalation exposure scenarios, firearm cleaning sprays showed low exposure margins, posing potential risks to sensitive populations.
Next Steps
Based on all information in the assessment, the two substances in the Decenes Group meet the criteria of CEPA Section 64(c), as their entry (or potential entry) into the Canadian environment in certain quantities, concentrations, or conditions may constitute a danger to human life or health. Accordingly, the government will initiate a public consultation within 90 days, proposing to list these two substances in the "Toxic substances list."
Further Information
