Which statement about Code 3.30 is true?

• A. Water
• B. LPG
• C. Liquid nitrogen
• D. Oil

Answer: (D)

Code 3.30 is used to label a category of liquids that includes oil-type fluids used for lubrication and related purposes. This code distinguishes those hydrocarbon liquids from other liquids or substances that have different hazard profiles or handling classifications. Oil fits this code because it is a petroleum-based liquid commonly encountered in machinery and plants, with properties and usage that match the category assigned to 3.30.

Water, LPG, and liquid nitrogen belong to different classifications: water is typically treated as a benign liquid with its own simple code; LPG is a gas (or cryogenic liquid in some forms) and is handled under codes relevant to flammable gases or cryogenic materials; liquid nitrogen is a cryogenic liquid with a code specific to extremely low-temperature hazards. Hence, oil is the item that aligns with Code 3.30.