NOx Testing Flexibility for Industrial Boilers

Summary#

This is a proposed change to the Multi‑Sector Air Pollutants Regulations (Part 1) published in the Canada Gazette on March 8, 2025. It would give some owners/operators of older industrial boilers and heaters more time and more flexible testing rules to measure nitrogen oxides (NOx) so they can be put in the correct performance class instead of being automatically treated as the worst class.

What it does#

• Extends the deadline to perform a NOx classification test for certain pre‑2016 boilers and heaters to December 31, 2025.
• Allows shorter or different test runs when a fixed 30‑minute test would damage equipment or endanger people.
• Lets units operate at the highest safe fraction of their capacity during a test instead of forcing a strict 60% requirement when that would be unsafe.
• Removes an unnecessary porthole location requirement for testing.
• Lowers the methane purity threshold used in the rules from 90% methane by volume to 85%.
• Removes the rule that a boiler’s “rated capacity” must be the value at commissioning (nameplate) if that is impractical.
• Adds clear rules for doing a single test on multiple boilers or heaters that share a common stack and how to allocate the measured NOx among devices.
• Gives equipment that was previously “deemed” the worst class (80, > 80 g/GJ) because they missed earlier tests a chance to be reclassified based on new test results.

Note: these are proposed amendments. The Canada Gazette notice gives a public comment period (see “Who’s affected” for the timing).

Who's affected#

• Operators of industrial boilers and heaters subject to Multi‑Sector Air Pollutants Regulations, Part 1. About 1,300 boilers and heaters across roughly 300 facilities fall under Part 1 overall.
• The proposal specifically targets the roughly 218 pre‑existing boilers and heaters that did not submit valid classification test results and were treated as worst‑performing (deemed class 80). Of those, at least 41 had confirmed testing or safety issues and 53 had invalid tests.
• Most affected units are in the oil and gas and oil sands sectors, but chemicals, pulp and paper, power plants and potash operations also appear among owners.
• The federal departments listed as sponsors are the Department of the Environment and the Department of Health (they prepared the analysis).

Public consultation: the notice allows comments for 60 days after publication (the Canada Gazette posting date is March 8, 2025).

Why it matters#

• Many operators say they could not do the original required tests safely under the current rules. Without these amendments, those units were being treated as class 80 and would have to meet a strict NOx limit of 26 g/GJ by January 1, 2026. Reclassification could avoid unnecessary equipment retrofits.
• The analysis estimates avoided industry capital costs of about $14,483,047 (present value) if affected units can be reclassified instead of being forced to upgrade.
• There are modest extra costs in the proposal: about $101,569 (present value) for additional stack testing for 13 units and about $9,648 (present value) in one‑time administrative familiarization costs for operators.
• Allowing the extra time and testing flexibility could mean up to about 25,333 tonnes more NOx emitted over the 2025–2035 analytical period compared with the scenario where all these units were upgraded immediately. The government’s analysis treats that as a possible trade‑off against avoiding unnecessary retrofits.
• Important to know: this is a proposed regulation, not final. If finalized, the text says the amendments would come into force upon registration. The public has the chance to comment during the 60‑day comment period that began with the Gazette posting.