The risk posed by a substance is determined by considering both its hazardous properties (its potential to cause adverse human health or ecological effects) and the amount of exposure there is to people and the environment.
The 4 substances in the Substituted Alkyl Imidazolines Group are associated with some health and ecological effects; however, the risk to Canadians is low at current levels of exposure. Therefore, it is proposed that these 4 substances are not harmful to human health or to the environment at levels of exposure considered in the assessment.
About these substances
The screening assessment focused on 4 of 8 substances referred to collectively under the Chemicals Management Plan (CMP) as the Alkyl Imidazolines and Salts Group.
The 4 substances addressed in the screening assessment are 1H-imidazole-1-ethanol, 2-(8-heptadecenyl)-4,5-dihydro- (CAS RN 95-38-5); 1H-imidazole-1-ethanol, 2-(heptadecenyl)-4,5-dihydro- (CAS RN 27136-73-8); 1H-imidazole-1-ethanamine, 4,5-dihydro-, 2-nortall-oil alkyl derivs. (CAS RN 68442-97-7); and 1H-imidazole-1-ethanol, 4,5-dihydro-2-isoheptadecyl- (CAS RN 68966-38-1).
Two other substances in the Alkyl Imidazolines and Salts Group (CAS RNs 21652-27-7 and 31135-57-6) were determined to be of low concern to both human health and the environment through other approaches.
The remaining 2 substances (CAS RNs 67633-57-2 and 68122-86-1) are part of another screening assessment.
The 4 substances addressed in the screening assessment are human-made and they do not occur naturally in the environment.
According to information gathered by the Government, these substances may be used in Canada in products available to consumers, including do-it-yourself (DIY) products (such as paint remover, lubricant and rust blocker) and hair products. They may have industrial uses, such as in lubricants and greases, oil and natural gas extraction, and as raw material to blend into industrial products.
Human and ecological exposures
Canadians may be exposed to CAS RN 95-38-5, CAS RN 27136-73-8, and CAS RN 68442-97-7 through the environment (for example, drinking water). The presence of these 4 substances is not expected in food.
For CAS RN 95-38-5, CAS RN 27136-73-8, and CAS RN 68966-38-1, the main sources of exposure for Canadians are from paint remover, lubricant and rust blocker, and hair conditioner.
According to information considered under the ERC Approach, all 4 substances in the Substituted Alkyl Imidazolines Group were identified as having low ecological exposure potential.
Key health and ecological effects (hazard)
For CAS RN 95-38-5 and CAS RN 68442-97-7, laboratory studies identified changes to body weight; which were considered to be the critical effects for characterizing the risk to human health in the assessment.
There were limited substance-specific health effects data for CAS RN 27136-73-8 and CAS RN 68966-38-1; therefore, a comparative approach using a similar chemical, called read-across, was used for assessing potential health effects. Changes to body weight in laboratory studies were also considered to be the critical effects used in the assessment of these substances.
According to information considered under the ERC approach, CAS RN 95-38-5, CAS RN 27136-73-8, and CAS RN 68966-38-1 were identified as having a high ecological hazard potential based on their potential ecotoxicity and moderate potential to cause adverse effects in aquatic food webs, given their bioaccumulation potential. CAS RN 68442-97-7 was identified as having a moderate ecological hazard potential based on its high potential to cause adverse effects in the aquatic food webs given its bioaccumulation potential.
Risk assessment outcomes
Based upon a comparison of levels to which Canadians may be exposed to these 4 substances and levels associated with health effects, it was determined that the risk to human health from these substances is low.
Based upon the outcome of the ERC Approach, these 4 substances are considered unlikely to be causing ecological harm.
The Government concluded that these 4 substances are not harmful to human health at levels of exposure considered in the assessment, and that they are not entering the environment at levels that are harmful to the environment.
These 4 substances may be found in products available to consumers. Canadians should follow any safety warnings and directions related to the product and dispose of products responsibly.