NOx testing changes for industrial boilers

Summary#

The federal Department of the Environment and Department of Health are proposing changes to the Multi-Sector Air Pollutants Regulations (Part 1) to give operators more time and flexibility when testing nitrogen oxides (NOx) from certain industrial boilers and heaters. The proposal would extend the deadline to complete classification testing to December 31, 2025, and aims to let about 218 pre-existing units that missed or had invalid tests avoid being automatically put in the strictest class.

What it does#

• Extends the deadline for re-testing pre-existing boilers and heaters until December 31, 2025 so operators can reclassify units that were automatically deemed worst-performing.
• Lets test runs be shorter or adjusted if a standard 30-minute run would damage equipment or endanger people.
• Allows operating at the highest safe share of rated capacity during testing instead of a fixed percentage when needed for safety.
• Removes some specific port-hole location requirements that made testing harder in some setups.
• Lowers the methane concentration threshold for “natural gas” from 90% to 85% by volume.
• Changes how “rated capacity” is defined so it can be taken from the manufacturer nameplate or manufacturer documentation rather than only the commissioning date.
• Adds rules to allow one stack test to be used for multiple boilers/heaters that share a common stack, and formulas for how to split results when other devices share that stack.
• Allows re-determination of a unit’s assigned NOx class (the “deemed 80” assignment) using stack or continuous monitoring tests performed during a reference period ending no later than December 31, 2025.

Who's affected#

• Operators of industrial boilers and heaters covered by MSAPR Part 1 — about 1,300 such units in Canada overall.
• Specifically, the proposal targets roughly 218 pre-existing boilers and heaters that did not submit valid NOx tests by the original deadline. 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 sector (about 158 of the 218), but other sectors (chemicals, pulp and paper, potash, power) and facilities across several provinces are included.
• Regulators and testing firms that carry out NOx stack testing may also see more work under the extended testing window and new common-stack testing rules.

Why it matters#

• If a unit could not complete a valid NOx test by the original deadline, the existing rules automatically treated it as the worst-performing class, which would require costly upgrades by January 1, 2026. The change gives operators a real chance to show their true emissions and avoid unnecessary retrofits.
• The government estimates industry avoided retrofit costs of about $14,483,047 (present value) under the proposal, while incremental administrative and testing costs to industry are much smaller (total present-value costs around $111,217, including $101,569 for some future stack tests).
• The proposal could mean more NOx emitted over the next decade compared with the strict baseline: up to about 25,333 tonnes of NOx over 2025–2035, according to the department’s screening.
• This is a proposal, not final law. There is a public comment window of 60 days from publication, and the amendments would come into force upon registration if finalized.