Clarifying engine emission standards for small Canadian vessels - SSB No.: 23/2022

RDIMS No .: 18860009
Date (Y-M-D) : 2022-10-21

We issue Ship Safety Bulletins for the marine community. Visit our Website at to view existing bulletins and to sign up to receive e-mail notices of new ones.

This bulletin replaces Ship Safety Bulletin No. 04/2018


This bulletin applies to Canadian vessels that:

  • are not more than 15 metres in length (the distance from the forward end of the foremost outside surface of the hull shell to the aft end of the aftermost outside surface of the hull shell),
  • voyage solely within Canadian waters, and
  • have marine engines (i.e. power output of more than 130 kW) that are subject to the International Maritime Organization (IMO) nitrogen oxides (NOx) Tier III emission standards.


This bulletin explains Transport Canada’s policy on small vessel compliance with the NOx emission standards set out in the Vessel Pollution and Dangerous Chemicals Regulations.

What you need to know

If a vessel is not more than 15 metres in length, its engine(s) don’t have to comply with the IMO NOx Tier III emission standards. This applies to engines that are installed for repowering and those installed in new vessels.

Instead, these marine engines must comply with the IMO NOx Tier II emission standards.

This policy will be in place until Dec 31, 2027.

Before that date, Transport Canada will review the latest developments in marine engine technology and determine whether small marine engines can meet the IMO Tier III emission standards without using selective catalytic reduction (SCR) or with smaller emission control technology.


1. Air emissions
2. Nitrogen oxides
3. Enforcement
4. Pollution prevention

Questions concerning this Bulletin should be addressed to:

Manager, Marine Air Emissions

Transport Canada
Marine Safety and Security
Tower C, Place de Ville
330 Sparks Street, 11th Floor
Ottawa, Ontario K1A 0N8

Contact us at: Email: or Telephone: 1-855-859-3123 (Toll Free).