(a) The following limits apply to the use of oil as fuel:
(1) Except as otherwise permitted by this section, no fuel oil with a flashpoint of less than 60 °C (140 °F) may be used.
(2) Except as otherwise permitted by § 58.50-1(b), fuel oil with a flashpoint of not less than 43 °C (110 °F) may be used in emergency generators.
(3) Subject to such further precautions as the Commanding Officer, Marine Safety Center, considers necessary, and provided that the ambient temperature of the space in which such fuel oil is stored or used does not rise to within 18 °F (10 °C) below the flashpoint of the fuel oil, fuel oil having a flashpoint of less than 140 °F (60 °C) but not less than 110 °F (43 °C) may be used.
(4) In a cargo vessel, fuel having a lower flashpoint than otherwise specified in this section - for example, crude oil - may be used provided that such fuel is not stored in any machinery space and that the Commanding Officer, Marine Safety Center, approves the complete installation.
(b) The flashpoint of oil must be determined by the Pensky-Martens Closed Tester, ASTM D 93 (incorporated by reference, see § 58.03-1).
[CGD 83-043, 60 FR 24775, May 10, 1995, as amended by USCG-1999-5151, 64 FR 67180, Dec. 1, 1999; USCG-2003-16630, 73 FR 65186, Oct. 31, 2008]