Introduction
Per- and polyfluoroalkyl substances (PFAS) are a large class of synthetic compounds valued for their resistance to heat, water, and oil. Their chemical stability has driven widespread industrial and commercial use, but also results in environmental persistence and potential health impacts. These characteristics have prompted regulatory scrutiny and emerging class action litigation in Canada.
Recent developments include Health Canada’s updated drinking-water objective, the Government of Canada’s Final State of PFAS Report and proposed Risk Management Approach, and publicly reported mapping of PFAS hotspots nationwide by the CBC and The Globe and Mail. Class actions are also on the rise, largely addressing property-value impacts due to the stigma of PFAS contamination in residential drinking water.
The Contaminant: PFAS
PFAS are entirely man-made fluorinated compounds in which hydrogen atoms in a carbon chain are replaced by fluorine. They do not occur naturally, and their molecular structure makes them chemically stable and highly resistant to degradation.
PFAS have been used in applications such as:
- Aqueous film-forming foams (AFFF) used in firefighting and training
- Non-stick coatings for cookware
- Water- and stain-resistant textiles, and
- Various industrial manufacturing processes.
These substances are often referred to as “forever chemicals” because they persist in the environment. Exposure to PFAS, particularly perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), has been linked to elevated cholesterol, thyroid disorders, reduced vaccine response, pregnancy-induced hypertension, and certain cancers, including testicular and kidney cancer.
In the United States, the EPA issued a Drinking Water Health Advisory in 2016 recommending a combined limit of 70 nanograms per litre (ng/L) for PFOA and PFOS, reflecting recognition of the health risks associated with even low concentrations.
Timeline of Canadian Federal PFAS Regulations
Canada’s regulatory approach to PFAS has evolved over two decades. Key milestones include:
- 2006: PFOS listed as a toxic substance under the Canadian Environmental Protection Act (CEPA) Schedule 1
- 2008: Restrictions on the manufacture, import, and use of PFAS-containing products
- 2012: Certain PFAS prohibited under the Prohibition of Certain Toxic Substances Regulations, SOR/2012-285
- 2013: PFOA added as a toxic substance under CEPA Schedule 1
- 2021: Publication of a Notice of Intent to regulate PFAS as a class, and
- 2025: Release of the Final State of PFAS Report and Proposed Risk Management Approach recommending PFAS (excluding fluoropolymers) be designated “toxic” under CEPA.
Health Canada’s Drinking Water Guidelines
History of Guidelines
Health Canada’s Drinking Water Guidelines for PFAS have progressively become more stringent:
- 2011: Maximum concentrations of 700 ng/L for PFOA and 300 ng/L for PFOS, with PFOA as a screening benchmark
- 2018: Revised to 200 ng/L for PFOA and 600 ng/L for PFOS, adding screening values for nine additional PFAS, and
- 2023: Draft guidance proposed a single limit of 30 ng/L for total PFAS concentration.
August 2024 Health Canada Interim Objective for PFAS in Drinking Water
On August 9, 2024, Health Canada updated its interim Objective for Canadian Drinking Water, setting a group-based threshold of 30 ng/L for the combined concentration of 25 PFAS compounds. This threshold replaces prior guidelines regulating nine individual PFAS. The guidance recommends maintaining PFAS concentrations “as low as reasonably achievable.” While legally unenforceable, it serves as a national benchmark.
Ontario Interim Advice for PFAS in Drinking Water
Ontario issued interim guidance recommending that the combined concentration of eleven PFAS compounds in drinking water should not exceed 70 ng/L. This guidance is advisory only and is not legally enforceable.
Canada’s Final State of PFAS Report
Recommendations and Risk Management
Released on March 5, 2025, the Final State of PFAS Report (the “Report”) recommended designating PFAS (excluding fluoropolymers) as “toxic” under CEPA Part 2, Schedule 1. This designation enables federal risk management, with a phased regulatory approach:
- Phase 1: Ban PFAS not currently regulated in firefighting foams
- Phase 2: Ban non-essential PFAS uses in consumer products such as cosmetics and food packaging, and
- Phase 3: Consider prohibitions on PFAS lacking feasible alternatives, including certain preion drugs or medical devices.
PFAS Hot Spots Across Canada
The Report identifies sites with historical use of AFFF—such as firefighting training areas, airports, and military bases—as “hot spots” with elevated PFAS levels. Many of these sites are located near communities that depend on private groundwater wells for drinking water. The Report states that PFAS contamination at these locations could potentially spread through groundwater and surface water, sometimes travelling several kilometres from the original source.
Moreover, maps published by the CBC and The Globe and Mail using data from the Federal Contaminated Sites Inventory illustrate how PFAS contamination at specific “hotspots” may be affecting private residential groundwater wells. These maps highlight legacy sites where AFFF was used, such as airports and military bases, and call attention to PFAS hotspots, emphasizing their proximity to communities that rely on private groundwater wells for their drinking water.
Potential Human Health Impacts
The Report emphasizes several human health concerns:
- Significant health effects: PFAS exposure can impact liver, kidneys, immune and reproductive systems, thyroid, nervous system, and metabolism
- Health effects at low levels: Evidence shows human health impacts can occur even at lower concentrations than previously understood, an
- Bioaccumulation: PFAS persist in the human body for years, with potential long-term health consequences.
Emerging Canadian PFAS Class Action Litigation
Class action litigation concerning PFAS contamination and its impact on residential property value is emerging in Canada, with claims filed in at least Ontario, Newfoundland and Labrador and Nova Scotia to date. These claims typically seek compensation for:
- Diminution in property value due to the stigma associated with potential drinking water contamination
- Remediation, engineering and professional costs, and
- Inability to obtain mortgage financing, re-financing and increased financing costs.
For example, in 2021, a class action was certified against the National Research Council of Canada alleging PFAS contamination of groundwater wells used for drinking water supplying residential properties near the National Fire Laboratory in Mississippi Mills, Ontario. The laboratory was historically used for fire safety research and for testing firefighting foams containing PFAS.
Conclusion
Public awareness of PFAS contamination and its potential health and environmental impacts is steadily growing in Canada, driven in large part by evolving scientific understanding. Research increasingly underscores the persistence, bioaccumulation, and health risks of PFAS, even at low concentrations, prompting updates to regulatory frameworks and drinking water guidelines. This attention has also been driven by the progressive lowering of federal acceptable PFAS levels in drinking water, and the extensive media coverage of contamination at PFAS hotspots.
At the same time, class action litigation is emerging across Canada, particularly in response to the alleged diminution in property value caused by the stigma of PFAS contamination. This form of litigation is especially significant for communities that rely on private groundwater wells potentially affected by the migration of PFAS from contaminated sites.
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