Perfluorooctane sulfonate, its salts and precursors (PFOS)

Update

Per- and polyfluoroalkyl substances (PFAS) are a class of thousands of human-made substances. In April 2021, the Government of Canada indicated that it is considering activities that would address PFAS as a class. Visit the PFAS web page for the latest information on publications and actions being considered under the Government's Chemicals Management Plan (CMP) related to PFAS.

On this page

• Risk management action milestones
• Environmental monitoring and surveillance in support of the Chemicals Management Plan
• Risk management strategy
• Ecological screening assessment
• State of the science report for a screening health assessment

Risk management action milestones

In December 2025, the Prohibition of Certain Toxic Substances Regulations, 2025 were published in the Canada Gazette, Part II: Vol. 159, No. 27 – December 31, 2025. The regulations further restrict certain toxic substances, including PFOS, its salts and precursors, and introduce restrictions on 2 new substances.

In May 2022, the proposed Prohibition of Certain Toxic Substances Regulations, 2022 were published in the Canada Gazette, Part I, Vol. 156, No. 20 - May 14, 2022 for a 75-day public comment period. Comments were considered in the development of the final regulations. Comments and the Government's responses are summarized in the Regulatory Impact Analysis Statement of the final regulations.

In December 2018, Environment and Climate Change Canada and Health Canada published the Consultation Document on Proposed Amendments to the Prohibition of Certain Toxic Substances Regulations, 2012 for PFOS, PFOA, LC-PFCAs, HBCD, PBDEs, DP and DBDPE. The objective of the consultation document was to inform stakeholders of the proposed amendments to the Prohibition of Certain Toxic Substances Regulations, 2012, solicit comments and request information. Comments and information received in response to the consultation document were considered in the development of the proposed Regulations Amending the Prohibition of Certain Toxic Substances Regulations, 2012.

In October 2018, a notice of intent was issued in the Canada Gazette, Part I: Vol. 152, No. 41 - October 13, 2018 indicating that the Department of the Environment and the Department of Health were initiating the development of amendments to the Prohibition of Certain Toxic Substances Regulations, 2012. There was a 30-day consultation period associated with this publication. Comments received on this publication were considered in the development of the proposed Regulations Amending the Prohibition of Certain Toxic Substances Regulations, 2012.

In October 2016, the Regulations Amending the Prohibition of Certain Toxic Substances Regulations, 2012 were published in the Canada Gazette, Part II: Vol. 150, No. 20 - October 5, 2016 and came into force in December 2016. These amendments maintained similar regulatory requirements for PFOS, its salts and precursors, and revised exemptions. The Perfluorooctane Sulfonate and its Salts and Certain Other Compounds Regulations were repealed when these amendments came into force.

In April 2015, the proposed Regulations Amending the Prohibition of Certain Toxic Substances Regulations, 2012 were published in the Canada Gazette, Part I: Vol. 149, No. 14 - April 4, 2015, for a 75-day public comment period. Comments received during this period were considered in the final development of these regulations. Comments and the Government's responses are provided in the summary of public comments received on the proposed Regulations Amending the Prohibition of Certain Toxic Substances Regulations, 2012.

The Government of Canada's consultation document on the examination of on-going exemptions for PFOS, its salts and precursors was published in January 2013 for a 60-day public comment period. Comments and the Government's responses are provided in the summary of public comments on the Consultation Document - Perfluorooctane Sulfonate, its Salts and Certain Other Compounds Regulations - Examination of On-going Exemptions. Comments received were considered during the development of the proposed risk management action.

Environmental monitoring and surveillance in support of the Chemicals Management Plan

In 2013, the Environmental Monitoring and Surveillance in Support of the Chemicals Management Plan: Perfluorooctane Sulfonate in the Canadian Environment report was published. This report found that through comparison to the draft Federal Environmental Quality Guidelines, the current PFOS concentrations that were measured presented a low potential for adverse effects on the organisms examined. However, PFOS in fish and bird eggs tended to exceed dietary guidelines for the protection of non-human mammalian and avian consumers, suggesting that this compound could represent a current risk to their wildlife predators.

Risk management strategy

In June 2006, the Risk Management Strategy for Perfluorooctane Sulfonate (PFOS) its Salts and its Precursors was released. The strategy describes the impact of PFOS, its salts and precursors on the environment and human health and describes details such as current uses, exposure sources, considerations, proposed objectives, risk management approach, proposed consultation approach and next steps.

The objective is to reduce concentrations of PFOS in the Canadian environment to the lowest level technically and economically feasible from all emission sources. The risk management approach includes regulations prohibiting the manufacture, use, sale, offer for sale and importation of PFOS, its salts and precursors, as well as continued engagement of international partners related to the long-term reduction and eventual elimination of the worldwide manufacturing and use of PFOS, its salts and precursors.

Ecological screening assessment

In June 2006, the Ecological Screening Assessment on Perfluorooctane Sulfonate, Its Salts and Its Precursors that Contain the C8F17O2 or C8F17SO3, or C8F17SO2N Moiety was released and the related notice was published in the Canada Gazette, Part I: Vol. 140 No. 26 - July 1, 2006 for a 60-day public comment period.

The screening assessment found that the presence of PFOS, its salts and precursors, in the environment results primarily from anthropogenic activity and that PFOS and its salts are extremely persistent in all media and can bioaccumulate and biomagnify in mammals and piscivorous birds. It was also concluded that PFOS, its salts and precursors are entering the environment in a quantity or concentration that have or may have an immediate or long-term harmful effect on the environment or its biological diversity.

State of the science report for a screening health assessment

In January 2006, the State of the Science Report for Perfluorooctane Sulfonate, Its Salts and Its Precursors that Contain the C8F17SO2 or C8F17SO3 Moiety was released and the related notice was published in the Canada Gazette, Part I: Vol. 140 No. 26 - July 1, 2006.

The state of the science report summarizes human health information on PFOS, its salts and precursors, with consideration given to information identified as of September 2003. The state of the science report found that PFOS, its salts and its precursors were not harmful to human health at the levels of exposure that were assessed.