Unmasking 198 Substances; PFAS Water Objective

Summary#

• The Gazette publishes two Environment and Health notices on August 10, 2024.
• Environment and Climate Change Canada plans to unmask the chemical identities of 198 substances that have been listed confidentially on the Domestic Substances List since 2004 or earlier.
• Health Canada sets a new drinking-water objective for a group of 25 per- and polyfluoroalkyl substances (PFAS) at 30 ng/L, and withdraws the earlier guidelines for PFOS and PFOA.

What it does#

• Environment notice (proposed)

  • Deletes 198 substances from Part 3 of the Domestic Substances List (where their names are masked).
  • Adds those same substances to Part 1 under their Chemical Abstracts Service (CAS) numbers, publicly revealing their identities.
  • Opens a public comment window of 60 days for feedback and for parties to apply to keep a masked name if they object.
  • The change is proposed and would only take effect when a final order is registered and published (in Canada Gazette, Part II).

• Health notice (final objective)

  • Establishes an objective for drinking water: the sum of concentrations of 25 specified PFAS must not exceed 30 ng/L.
  • Withdraws the previous drinking-water guidelines for PFOS and PFOA; the single objective replaces those separate guidelines and some screening values.
  • Recommends keeping PFAS levels in drinking water “as low as reasonably achievable” while further reassessments proceed.
  • Notes available methods and municipal treatment options (e.g., granular activated carbon, reverse osmosis) but says meeting low concentrations can be technically and operationally challenging.

Who's affected#

• Businesses and sectors tied to chemicals:
  • Manufacturers, importers, and suppliers of the 198 substances listed on the Domestic Substances List.
  • Companies that relied on those masked listings to protect confidential business information.
• Water and public-health stakeholders:
  • Municipal water utilities and operators who monitor and treat drinking water for PFAS.
  • Private well owners in areas with known PFAS contamination (for example, near firefighting-foam use), who may consider certified point-of-use or point-of-entry devices.
  • Environmental labs that test water for PFAS and provinces/territories involved in drinking water regulation.
• The public and communities:
  • Residents living near industrial sites or places where PFAS-containing foams were used may be most likely to notice local testing or treatment changes.
• If it is unclear who is affected:
  • Some downstream users or small suppliers may not be able to tell immediately whether the unmasked substances are in their products; the notice advises contacting the New Substances program to confirm.

Why it matters#

• Transparency and information:
  • Unmasking 198 substances means the public, researchers, and regulators will know exactly which chemicals are on the Canadian market. That can help with monitoring, research, and informed purchasing or regulation.
  • It may reduce the scope of long-running confidentiality claims and change how companies protect trade secrets.
• Drinking-water protection:
  • Setting a group-based objective of 30 ng/L for 25 PFAS shifts the focus to combined exposure to multiple PFAS rather than only a few named chemicals. This aligns with growing scientific concern about simultaneous exposure to many PFAS.
  • For water systems and homeowners, meeting this low objective may require testing and treatment upgrades. The notice highlights both the technical feasibility and the practical challenges (cost, operation, and disposal of PFAS-contaminated treatment waste).
• Next steps people might want to take:
  • Affected companies can consider submitting masked-name applications if they object to unmasking.
  • Municipalities and well owners can review testing and treatment options.
  • Interested members of the public or organizations can comment within 60 days on the proposed unmasking.