The risks posed by a substance are determined by both its hazardous properties (potential to cause adverse human health or ecological effects) and the amount or extent of exposure to people or the environment.
When needed, the Government implements risk management measures under CEPA 1999 and other federal acts to help prevent or reduce potential harm.
The Government is proposing that all 6 substances in the Selected C3-C5 Alcohols Group are not harmful to human health or to the environment at levels of exposure considered in the assessment.
About these substances
The screening assessment focuses on 6 substances, referred to collectively as the Selected C3-C5 Alcohols Group under the third phase of the Chemicals Management Plan (CMP). These substances are 1-propanol, 2-propanol, propylene glycol, isobutanol, tert-butanol, and 1-pentanol.
1-Propanol and 2-propanol occur naturally in the environment, while the other 4 substances in the group do not.
According to information gathered by the Government, these substances (except propylene glycol) are mainly used in Canada in paints and coatings. Additional uses include in ink, toners and colourants; cleaning and furnishing care (1-propanol, 2-propanol and isobutanol); automotive, aircraft and transportation (2-propanol and 1-pentanol); personal-care products, adhesives and sealants; and oil and natural gas extraction (2-propanol).
Substances in the Selected C3-C5 Alcohols Group may also be used in cosmetics (all except 1-pentanol), as food additives (2-propanol and propylene glycol), food flavouring agents (1-propanol, 2-propanol, isobutanol and 1-pentanol), components in the manufacture of food packaging materials (all), incidental additives (tert-butanol), medicinal or non-medicinal ingredients in drugs (all except 1-pentanol) including natural health products (1-propanol, 2-propanol, propylene glycol, and tert-butanol), as active ingredients in pest control products (2-propanol and propylene glycol), as formulants (not an active ingredient) in pest control products (all), and in other products available to consumers.
Human and ecological exposures
Since 1-propanol, 2-propanol, propylene glycol, isobutanol, and 1-pentanol are considered to be of low hazard potential, exposure estimates were not developed for the assessment.
People living in Canada may be exposed to tert-butanol from air and drinking water, and from the use of various products available to consumers, such as cosmetics and drugs, including natural health products.
According to the information considered under the ERC Approach, 5 substances in the Selected C3-C5 Alcohols Group were identified as having low ecological exposure potential. tert-Butanol, however, was classified as having a high ecological exposure potential based on a critically long half-life in air (ability to stay in the air for a long-time) in combination with high reported use quantities.
There were limited health effects (hazard) data for isobutanol and 1-pentanol; therefore, a comparative approach using similar chemicals, called read-across, was used for assessing potential health effects.
Based on laboratory studies, the critical effects used to characterize human health risk to tert-butanol were effects on the kidneys and thyroid cancer.
According to information considered under the ERC Approach, all 6 substances in the Selected C3-C5 Alcohols Group were identified as having a low ecological hazard potential.
Consideration of subpopulations who may be more susceptible or highly exposed
There are groups of individuals within the Canadian population who, due to greater susceptibility or greater exposure, may be more vulnerable to experiencing adverse health effects from exposure to substances.
Certain subpopulations are routinely considered throughout the screening assessment process, such as infants, children, and people of reproductive age. For instance, age-specific exposures are routinely estimated and developmental and reproductive toxicity studies are evaluated for potential adverse health effects. These subpopulations were taken into account in the risk assessment outcomes.
In addition, people living near industrial releases were considered in the screening assessment of tert-butanol.
Risk assessment outcomes
On the basis of the information presented in the screening assessment, the risk to human health from 1-propanol, 2-propanol, propylene glycol, isobutanol, and 1-pentanol is low.
Based upon a comparison of levels to which people living in Canada may be exposed to tert-butanol and levels associated with health effects, it was determined that the risk to human health from this substance is also low.
Based upon the outcome of the ERC Approach, these 6 substances are considered unlikely to be causing ecological harm.
Proposed screening assessment conclusions
The Government is proposing that all 6 substances in the Selected C3-C5 Alcohols Group are not harmful to human health at levels of exposure considered in the assessment, and that these 6 substances are not entering the environment at levels that are harmful.
Substances in the Selected C3-C5 Alcohols Group may be found in products available to consumers. People living in Canada should follow any safety warnings and directions related to the product and dispose of products responsibly.
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