Authority to regulate emissions from internal combustion engines in Canada rests with Environment and Climate Change Canada and Transport Canada. Under the Canadian Environmental Protection Act 1999 (CEPA 1999) , Environment Canada has the authority to regulate emissions from on-road engines, as well as from most categories of off-road engines. Authority to regulate emissions from aircraft, railway locomotives and commercial marine vessels remains with Transport Canada. Regulations have been adopted to control emissions of criteria air contaminants (CAC) as well as greenhouse gases (GHG).
The general approach to setting vehicle emission standards in Canada has been to harmonize them with US EPA federal standards. In 1988, on-road vehicle emission standards were first aligned with the US federal standards. In February 2001, the Minister of the Environment in the Federal Agenda on Cleaner Vehicles, Engines and Fuels  set out a number of policy measures that continued the harmonization of on-road emission standards, as well as expanded this harmonization by developing emission standards for off-road engines and standards for fuels that are aligned with the federal US requirements.
An important aspect of the harmonization with US standards is the recognition of emission certificates issued by the US EPA. Under most Canadian regulations—including emission standards for light-duty vehicles, heavy-duty engines and off-road engines—there are two ways of demonstrating emission compliance:
- US EPA emission certificate—Every model of vehicle or engine that is certified by the US EPA and that is sold concurrently in Canada and the United States is required to meet the same emission standards in Canada as in the United States. The term concurrent sales means that for a US EPA certificate to be valid in Canada, at least one engine or vehicle covered by this certificate must be sold in a given year in the United States. Most vehicles and engines are sold in Canada under this concurrent sales principle. These vehicles and engines must be affixed with a US EPA emission label and do not require a Canadian emission approval or labeling.
- Environment Canada emission approval—Vehicles and engines that do not have a valid US EPA emission certificate must be emission approved by Environment Canada and affixed with a Canadian emission label.
Certain US emission standards are phased-in over a number of years, with the respective US EPA regulations specifying detailed implementation schedules. Under the concurrent sales approach, the interim phase-in schedules may not be specified in the Canadian regulations. The final phased-in standards apply to all vehicles and engines sold in Canada beginning with the model year that they apply to 100% of a class of vehicles or engines in the United States.
Most Canadian emission standards for onroad engines and vehicles are harmonized with the US EPA regulations in regards to both the emission requirements and the implementation dates. On the other hand, many Canadian emission standards for off-road engines have been implemented with several years of delay compared to the corresponding US EPA regulations.
On-Road Engines and Vehicles
Criteria Air Contaminants (CAC) Emission Regulations
Canadian federal regulations establishing exhaust emission limits for on-road vehicles were first promulgated in 1971 under the Motor Vehicle Safety Act which was administered by Transport Canada.
On March 13, 2000, under the Canadian Environmental Protection Act 1999 (CEPA 1999) , legislative authority for controlling on-road vehicle emissions was transferred from Transport Canada to Environment Canada.
In June 2001, Environment Canada signed a Memorandum of Understanding (MOU) with the Canadian Vehicle Manufacturers Association, the Association of International Automobile Manufacturers of Canada, and the member companies of those associations. The MOU formalized an industry commitment to market the same low emission light-duty vehicles and light-duty trucks in Canada as in the US for model years 2001-2003.
On January 1, 2003, the On-Road Vehicle and Engine Emission Regulations  were promulgated under CEPA 1999. The Regulations aligned vehicle and engine certification requirements with those of the US EPA beginning January 1, 2004 and including the US Tier 2 program for new light-duty vehicles, light-duty trucks and medium-duty passenger vehicles, and Phase 1 (US2004) and Phase 2 (US2007) programs for new heavy-duty vehicles and engines.
The Regulations set out technical standards for vehicles and engines for exhaust, evaporative and crankcase emissions, on-board diagnostic systems and other specifications related to emission control systems. The Regulations defined several phase-in schedules, as follows: Tier 2 standards for light-duty vehicles and light light-duty trucks (2004-2007); Tier 2 standards for heavy light-duty trucks and medium-duty passenger vehicles (2004-2009); Phase 1 (2005) and Phase 2 (2008-2009) standards for complete heavy-duty vehicles; and Phase 1 (2004-2006) and Phase 2 (2007-2010) standards for heavy-duty engines.
On July 16, 2015, amendments were adopted to the On-Road Vehicle and Engine Emission Regulations  that harmonize Canadian requirements with the US EPA Tier 3 emission regulations, starting with the 2017 model year.
The On-Road Vehicle and Engine Emission Regulations also specify emission standards for motorcycles, which are aligned with US EPA emission standards.
Greenhouse Gas Emission Regulations
The main regulatory steps in the development of Canadian GHG emission and fuel economy standards include:
- The first Canadian program to reduce GHG emissions from light-duty vehicles was a voluntary agreement signed in 2005 by the Ministry of Natural Resources Canada, the Canadian Vehicle Manufacturers’ Association, and the Association of International Automobile Manufacturers of Canada. Under the MOU, automobile manufacturers agreed to reduce total GHG emissions from new light-duty vehicles in Canada by 5.3 megatonnes by 2010, relative to a “business-as-usual” reference case projection of vehicle emissions in 2010. This rather obscure mass-based metric was chosen, rather than a percentage reduction target, because the automakers apparently feared at the time that making a percentage commitment could undermine their lawsuit in the USA to block California GHG emission standards.
- The first mandatory program was introduced in October 2010, when Environment Canada published Passenger Automobile and Light Truck Greenhouse Gas Emission Regulations . These Regulations prescribed progressively more stringent annual emission standards for new light-duty vehicles of model years 2011-2016, in alignment with those of the US EPA/NHTSA.
- In February 2013, Environment Canada adopted Heavy-duty Vehicle and Engine Greenhouse Gas Emission Regulations  that introduced GHG emission requirements for model year 2014 and later heavy-duty trucks, aligned with US EPA Phase 1 regulations.
- In September 2014, Environment Canada published Regulations Amending the Passenger Automobile and Light Truck Greenhouse Gas Emission Regulations , which extended the GHG emission and fuel economy program for light-duty vehicles onto model years 2017-2015, in harmonization with the respective US EPA/NHTSA regulations.
- In October 2014, Environment Canada issued a Notice of Intent  to develop GHG emission regulations for post-2018 model years of heavy-duty vehicles. The regulations will be harmonized with US EPA Phase 2 GHG regulations.
Vehicle Weight Classes
The regulations define the weight classes for vehicles and engines as outlined below:
|Class||GVWR, kg (lb)|
|Light-Duty Vehicle||≤3,856 (8,500)|
|Light-Duty Truck||≤3,856 (8,500)|
|- light light-duty truck||≤2,722 (6,000)|
|- heavy light-duty truck||>2,722 to 3,856 (6,000 to 8,500)|
|Medium-Duty Passenger Vehicle||3,856 to <4,536 (8,500 to 10,000)|
|Complete Heavy-Duty Vehicle (Otto cycle only)||3,856 to 6,350 (8,500 to 14,000)|
|Heavy-Duty Vehicle/Heavy-Duty Engine||>3,856 (8,500)|
|- light heavy-duty engine||<8,847 (19,500)|
|- medium heavy-duty engine||8,847 to 14,971 (19,500 to 33,000)|
|- heavy heavy-duty engine||>14,971 (33,000)|
Off-Road Engines and Vehicles
Off-Road Compression-Ignition Engines
Emissions from Off-Road Compression-Ignition Engines, such as those used in construction and agricultural machinery, have been regulated since 2006. The original regulation was aligned with US EPA Tier 2 and Tier 3 standards. Amendments adopted in 2011 harmonized the regulations with US EPA Tier 4 standards.
Large Spark-Ignition Engines
Emissions from large spark-ignition engines used in industrial applications such as forklifts and ice re-surfacing machines remain unregulated. Environment Canada has been planning to propose Off-Road Compression-Ignition and Large Spark-Ignition Engines Emission Regulations to replace the existing Off-Road Compression-Ignition Engines Regulations. The new regulations will include emission standards for both CI and SI off-road engines.
Off-Road Small Spark-Ignition Engines
Off-Road Small Spark-Ignition Engines have been emission regulated since 2005. The regulations have been harmonized with the US EPA Phase 2 standards for small utility engines. Under amendments proposed in 2016, US EPA Phase 3 emission standards would become effective from 2018.
Marine SI Engines & Off-Road Recreational Vehicles
An MOU with the Canadian Marine Manufacturers Association covered marine spark ignition engines and under its terms, engine manufacturers voluntarily committed to supply engines designed to meet United States federal emissions standards into Canada starting with the 2001 model year.
On February 4, 2011, Environment Canada adopted Marine Spark-Ignition Engine, Vessel and Off-Road Recreational Vehicle Emission Regulations . These emission regulations apply to outboard engines, inboard engines, personal watercraft, snowmobiles, off-road motorcycles and all-terrain vehicles (ATV). Most of the regulatory provisions came into force from April 5, 2011. The standards align with corresponding US EPA rules for marine spark-ignition engines and off-road recreational engines and vehicles.
Emission standards for Marine Engines (< 37 kW) and for ships are under the authority of Transport Canada. Emission standards for marine engines with power outputs more than 130 kW are aligned with IMO MARPOL 73/78 Annex VI.
The authority for regulating railway locomotive emissions lies with Transport Canada under the Railway Safety Act. Environment Canada monitored locomotive emissions through information provided under a MOU signed by Environment Canada, the Canadian Council of Ministers of the Environment and the Railway Association of Canada in 1995. The MOU set a cap on annual NOx emissions from railway locomotives operating in Canada of 115,000 tonnes per annum. The MOU expired in 2005.
A second MOU was signed between the Railway Association of Canada, Transport Canada and Environment Canada in 2007. The MOU set targets to reduce the intensity of GHG emissions and “encouraged” the reduction of criteria pollutant emissions. The MOU covered the 2006–2010 period.
In 2016, Transport Canada proposed locomotive emission standards . The proposed regulations limit emissions of NOx, PM, HC and CO from locomotives operated by railway companies under federal jurisdiction. The emission standards align with the US EPA locomotive emission standards, in terms of both emission limits and effective dates.
In June 2016, Environment Canada adopted the Multi-Sector Air Pollutant Regulations (MSAPR) for stationary spark-ignition gaseous fuel-fired engines, gaseous fuel-fired non-utility boilers and heaters, and cement kilns . The regulations limit the amount of NOx emitted from stationary SI natural gas engines used by select industrial facilities, such as engines used for gas compressions or back-up generators. The MSAPR performance standards for new engines are comparable—but not identical—to the US EPA NSPS standards for stationary SI internal combustion engines. There are two compliance phases, starting in 2021 and in 2026.
Emissions from compression ignition stationary engines are not regulated at the federal level in Canada. Environment Canada has been planning pre-consultations on the proposed regulations to be held in 2016-2017.