MARPOL Annex VI Regulation 13.5.1.2 generally prohibits the operation of any engine in the North American and US Caribbean Sea NOx Emission Control Areas (ECA) that does not comply with the MARPOL Annex VI Tier III requirements if the engine is installed on a ship that is constructed in 2016 or later, or if the engine undergoes a major conversion in 2016 or later.

In some cases, no MARPOL compliant engines of the size required were available at the time of ship construction or no MARPOL compliant engines of the required size were available that also satisfied applicable Clean Air Act requirements.

In lieu of meeting MARPOL Annex VI Tier III performance standards, engines covered by this guidance may instead be certified by the US Environmental Protection Agency as meeting Clean Air Act Tier 3 requirements under 40 CFR part 1042.

Only the following categories of ships and engines will qualify under this Work Instruction:

Engines certified to meet Clean Air Act Tier 3 requirements are available and will be accepted in the short-term. Thus, EPA certification to Clean Air Act Tier 3 standards will be required to qualify under this Work Instruction for US-flagged and foreign-flagged vessels.

Officers in Charge, Marine Inspection, affected companies, and Recognized Organizations that issue International Air Pollution Prevention certificates on behalf of the US are encouraged to apply this Work Instruction as it relates to the installation and certification of “qualifying engines” that are required to meet IMO Tier III performance standards.