Chloramine guideline and Non-domestic deletions

Summary#

This issue of the Canada Gazette (Part I) published on February 8, 2020 contains several short government notices. It includes three orders under the Canadian Environmental Protection Act, 1999 that remove specific substances from the Non‑domestic Substances List, and a final guidance document from Health Canada that says a numeric drinking‑water limit for chloramines is not needed on health grounds.

What it does#

• Order 2020-87-02-02 Amending the Non-domestic Substances List

  • Deletes a set of chemical entries from Part I of the Non‑domestic Substances List (specific CAS numbers are listed in the Gazette).
  • Comes into force on the same day as the related order that amends the Domestic Substances List.

• Order 2020-87-03-02 Amending the Non-domestic Substances List

  • Deletes two entries from Part I and two entries from Part II of the Non‑domestic Substances List (one pair includes named reaction‑product chemicals).
  • Comes into force on the same day as its related Domestic Substances List order.

• Order 2020-87-05-02 Amending the Non-domestic Substances List

  • Deletes two entries from Part I of the Non‑domestic Substances List.
  • Comes into force on the same day as its related Domestic Substances List order.

• Final guideline for Canadian drinking water quality for chloramines (Health Canada)

  • The guideline says it is not necessary to set a maximum acceptable concentration for chloramines in drinking water on the basis of health effects.
  • The document focuses on inorganic chloramines (monochloramine, dichloramine, trichloramine) and notes that monochloramine is usually the main form in treated water.
  • It notes that chloramine residuals in distribution systems are typically below 4 mg/L.
  • It records that other organizations have used numerical values: the U.S. EPA has a 4 mg/L maximum residual disinfectant level, and the World Health Organization and Australia set 3 mg/L for monochloramine.
  • The guideline says measures to limit chloramines or their by‑products must not reduce the effectiveness of disinfection.
  • The technical document had a public comment period of 60 days in 2019 and was updated based on feedback.
  • It does not set an aesthetic objective (for taste/odour) and does not assess all by‑products formed by chloramination.

Who's affected#

• Companies that import, manufacture or handle the specific chemicals named in the Non‑domestic Substances List deletions. (Exactly which businesses are affected depends on whether the matching Domestic Substances List orders are brought into force.)
• Municipal water utilities and water system operators that use or consider using chloramines for disinfection.
• Consumers who notice taste or odour in tap water or who use in‑home water treatment devices to remove disinfectants.
• Public health and environmental staff who set local water treatment practices or monitor water quality.

Why it matters#

• For businesses dealing with the deleted chemicals, changing entries on the Non‑domestic Substances List can alter reporting or regulatory status — but the practical effect depends on the timing and content of the matching Domestic Substances List orders.
• For the public and utilities, the Health Canada guideline means there is no new national health‑based numeric limit for chloramines. That supports continued use of chloramines where they help control microbes and reduce some disinfection by‑products, while reminding operators to watch for system effects such as corrosion, nitrification and different by‑products.
• For consumers, Health Canada’s view is that the health risk from chloramines at levels normally found in Canadian drinking water is low, and that keeping water properly disinfected is more important than removing all traces of chloramines.