The Government of Canada conducted a science-based evaluation of ethane, propane, isobutane, butane and butane (branched and linear), called a screening assessment to address the potential for harm to Canadians and the environment.
Under the Canadian Environmental Protection Act, 1999 (CEPA 1999), 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 or to the environment. A substance may have hazardous properties; however, the risk to human health or to the environment may be low depending upon the level of exposure.
Ethane, propane, isobutane, butane and butane (branched and linear) have low hazardous properties, and exposure to Canadians is low. Therefore, it was concluded that these 5 substances are not harmful to human health or to the environment.
These substances are naturally found in crude oil and natural gas and are separated from these complex petroleum substances at industrial facilities (for example, petroleum refineries and natural gas processing plants).
The substances in this assessment are used primarily as domestic and industrial fuels and as raw materials for manufacturing ethylene and other petrochemicals.
Propane, isobutane and butane are also used as aerosol propellants in spray products (for example, air fresheners, cooking spray, cleaning products and spray paints and spray lubricants).
Industry data collected by the Government indicates that all 5 substances are manufactured in and imported into Canada. More information on the data collected by the Government can be found in the specific information gathering initiatives.
Exposure of the general population to these substances may occur from indoor air, such as the use of aerosol propellants (in other words, spray products) in products available to consumers and from outdoor air, particularly in the vicinity of industrial and petroleum facilities.
These 5 substances may be released during the extraction of natural gas and petroleum, during their processing and refining at petroleum facilities, and during chemical manufacturing.
Key health and ecological effects (hazard)
These substances have not been identified as posing a high hazard to human health. There were also no classifications identified by other national or international agencies for carcinogenicity (cancer-causing agent), genotoxicity (damage to genetic material), developmental toxicity or reproductive toxicity.
For the ecological assessment, the laboratory studies demonstrated no adverse effects on terrestrial organisms.
Risk Assessment Outcomes
Exposure to these substances through their use as aerosol propellants in spray products, and in the vicinity of petroleum facilities is not expected to cause harm to the general population of Canada.
Results of the final screening assessment indicate that although these 5 substances may remain in the atmosphere for a long time, they are not expected to accumulate in or directly cause harm to organisms.
Furthermore, the quantity of these 5 substances that may be released in the environment is below the level expected to cause harm to organisms.
The Government of Canada concluded that ethane, propane, isobutane, butane and butane (branched and linear) are not harmful to human health at current levels of exposure
The Government of Canada also concluded that these 5 substances are not entering the environment at levels that constitute a danger to the environment.
Important to know
These 5 substances may be found in certain products available to consumers. Canadians should follow any safety warnings and directions on product labels and dispose of products responsibly.
Canadians who may be exposed to any of these substances in the workplace should consult with their employer and an occupational health and safety (OHS) representative about safe handling practices, applicable laws and requirements under the OHS legislation and the Workplace Hazardous Materials Information System (WHMIS).
