ECA marine fuel
ECA marine fuel is diesel, distillate, or residual fuel that meets the criteria of paragraph (ttt)(1) of this section, but not the criteria of paragraph (ttt)(2) of this section.
(1) All diesel, distillate, or residual fuel used, intended for use, or made available for use in Category 3 marine vessels while the vessels are operating within an Emission Control Area (ECA), or an ECA associated area, is ECA marine fuel, unless it meets the criteria of paragraph (ttt)(2) of this section.
(2) ECA marine fuel does not include any of the following fuel:
(i) Fuel used by exempted or excluded vessels (such as exempted steamships), or fuel used by vessels allowed by the U.S. government pursuant to MARPOL Annex VI Regulation 3 or Regulation 4 to exceed the fuel sulfur limits while operating in an ECA or an ECA associated area (see 33 U.S.C. 1903).
(ii) Fuel that conforms fully to the requirements of this part for NRLM diesel fuel (including being designated as NRLM).
(iii) Fuel used, or made available for use, in any diesel engines not installed on a Category 3 marine vessel.
40 CFR § 80.2
Definitions apply in this part as described in this section.