The report proposes to conclude that the four substances do not meet any of the criteria set out in section 64 of the Act: CAS RN 95-38-5, 27136-73-8, 68442-97-7 (tall oil, diethylenetriamine imidazoline), and 68966-38-1.
Commercial and industrial uses of the substances in this group include processing aids, electronics solder, concrete production, rubber compounding, steelmaking and formulation of paints and coatings, as well as products available to consumers, such as adhesives or binding agents, and cosmetics.The predominant sources of exposure to the Canadian general population are paint removers, lubricants, and rust blockers, and hair conditioners for N-b-hydroxyethyl oleyl imidazoline (CAS RN 95-38-5), oleyl hydroxyethyl imidazoline (CAS RN 27136-73-8), and isostearyl imidazoline (CAS RN 68966-38-1), respectively. Specific products identified on the market containing oleyl hydroxyethyl imidazoline are lubricants and greases, corrosion inhibitors, and disinfectants for industrial use.
Potential uses of products containing tall oil, diethylenetriamine imidazoline are expected to be limited to industrial or specialized applications that would not be expected to result in exposures to the Canadian general population.
The Minister of Health (the ministers) propose to take no further action at this time under section 77 of the Act for the three substances identified under subsection 73(1) of the Act (CAS RN 95-38-5, 27136-73-8, and 68966-38-1).
The ministers also propose to take no further action on tall oil, diethylenetriamine imidazoline at this time.
Risk Assessment Approach
Dermal exposure from products available to consumers was among the main health concerns. However, estimated inhalation exposures from use of aerosol products were analyzed but due to the very low vapour pressures (10-6 Pa or lower at 25°C) of all four members of the group, any potential non-aerosol exposures via the inhalation route were not expected.
The Read-across approach was used for health assessment. The suitable analogue, one of the substances in the group N-b-hydroxyethyl oleyl imidazoline, because it contained an imidazoline moiety has been used to inform the human health assessment for two other substances in the group.
Based on the paint remover product description, there are various potential methods of applying the product, including the use of a spray or brush. Various application methods were considered, and the pneumatic spray scenario in ConsExpo Web (2016) was selected to represent the sentinel paint remover scenario as it resulted in the highest levels of exposures (i.e., in comparison to the exposures resulting from the brush-on paint remover scenario from ConsExpo Web 2016). Using certain spray can default values in ConsExpo Web (2016) that are based on a paint scenario for a lubricant and rust blocker aerosol product is a source of uncertainty and specific adjustments were made where possible including the assumption that one can of the product (200 mL) was used per application event.
There were no animal studies via dermal and inhalation routes available for the Alkyl Imidazolines Group, no chronic or carcinogenicity studies, modelled environmental concentrations were used in the absence of monitoring data, and a default dermal absorption factor of 10% was applied to N-b-hydroxyethyl oleyl imidazoline, oleyl hydroxyethyl imidazoline, and isostearyl imidazoline in the absence of chemical-specific empirical dermal absorption data.