Noxious liquid substance
Noxious liquid substance (NLS) means (1) Each substance listed in 151.47 or 151.49 of this chapter; (2) Each substance having an A, B, C, or D beside it's name in the column headed Pollution Category in table 1 of 46 CFR part 153; and (3) Each substance that is identified as an NLS in a written permission issued under 46 CFR 153.900(d).