Noxious liquid substance (NLS) means--
(a) Each substance listed in 33 CFR 151.47 or 151.49;
(b) Each substance having an ``A,'' ``B,'' ``C,'' or ``D'' beside its name in the column headed ``IMO Annex II pollution category'' in table 1 of part 153 of this chapter; and
(c) Each substance that is identified as an NLS in a written permission issued under Sec. 153.900(d) of this chapter. [USCG-2000-6927, 70 FR 74676, Dec. 16, 2005]