What are the three categories of Noxious Liquid Substances?

• A. X, Y, Z
• B. A, B, C
• C. 1, 2, 3
• D. Alpha, Beta, Gamma

Answer: (A)

Noxious Liquid Substances are grouped by hazard into three categories: X, Y, and Z. This classification guides how strict the discharge rules and handling requirements must be, to protect the marine environment. Substances in category X are the most hazardous and discharges are essentially prohibited; category Y covers substances with medium hazard, where discharges may be allowed only under specific conditions and restrictions; category Z includes substances with lower hazard and has the least stringent limitations among the three. The other label sets you might encounter—such as Alpha, Beta, Gamma or A, B, C—are not used for this classification, so X, Y, Z is the correct trio.