Industry-restricted petroleum and refinery gases - information sheet

Updated March 6, 2019:

The Final Screening Assessment for Industry-Restricted Petroleum and Refinery Gases was published in January 2014 under the Chemicals Management Plan (CMP). The assessment is summarized in this information sheet (formerly public summary) and has not changed. The section in this information sheet entitled "Preventive actions and reducing risk" communicates updates in risk management activities, namely:

On this page


  • The Government of Canada conducted a science-based evaluation, called a screening assessment, of 4 industry-restricted PRGs, to address the potential for harm to Canadians and to 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 and 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.
  • As a result of the screening assessment, the Government concluded that these substances are harmful to human health, but not to the environment, at levels of exposure at the time of the assessment.

About these substances

  • The screening assessment focuses on 4 substances, referred to collectively under the CMP as industry-restricted PRGs in the Petroleum Sector Stream Approach (Stream 2).
  • PRGs are a category of complex combinations of petroleum hydrocarbons. Their compositions vary depending on the source of the crude oil, bitumen, or natural gas, and how they are processed.
  • According to information gathered by the Government, PRGs are often used as fuel in petroleum facilities, or are further refined or blended into other products.
  • Industry-restricted PRGs may leave a petroleum-sector facility and be transported to other industrial facilities (for example, for use as a feedstock, fuel or blending component), but are not expected to be available to the public.

Human and ecological exposures

  • Exposure to Canadians is expected to be limited to the unintentional emissions of these substances in the vicinity of petroleum facilities.
  • Canadians are not expected to be exposed to industry-restricted PRGs during handling and transportation, because these gases are transported by pressurized systems designed to prevent or minimize releases.
  • Although measures and practices are in place to limit the releases of petroleum substances within the facility, unintentional releases of these substances into the atmosphere may occur.

Key health and ecological effects (hazard)

  • Potential carcinogenicity (ability to cause cancer) was considered to be the important or "critical" effect for these substances, used for characterizing the risk to human health in the assessment.
  • Some of these substances are also associated with ecological effects, based upon their potential to remain in the environment for a long time.

Risk assessment outcomes

  • Based upon the information presented in the screening assessment, it was determined that these substances may pose a risk to human health, as there is a small portion of Canadians that may be exposed in the vicinity of petroleum facilities.
  • It was also determined that there is low risk of harm to the environment from these substances, as concentrations of components of PRGs in air surrounding petroleum facilities are not expected to be at levels that could result in harm to the environment.
  • None of these substances contains components that meet the bioaccumulation criteria as set out in the Persistence and Bioaccumulation Regulations of CEPA 1999; however, many of the components of industry-restricted PRGs meet the persistence criteria, as they persist in the atmosphere.
  • The Government published the Final Screening Assessment for Industry-Restricted Petroleum and Refinery Gases on January 18, 2014.

Screening assessment conclusions

  • As a result of the screening assessment, the Government concluded that these 4 industry-restricted PRGs are harmful to human health, at levels of exposure at the time of the assessment.
  • The Government also concluded that the substances are not entering the environment at levels that are harmful to the environment at the time of the assessment.

Preventive actions and reducing risk

Related information

  • Canadians who may be exposed to 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 OHS legislation and the Workplace Hazardous Materials Information System (WHMIS).
Report a problem or mistake on this page
Please select all that apply:

Thank you for your help!

You will not receive a reply. For enquiries, contact us.

Date modified: