Which statement is true about Packing Group 1?

• A. Vapor pressure is high
• B. Boiling Point > 35°C
• C. Boiling Point <= 35°C
• D. Flash Point <= -10°C

Answer: (C)

Packing Group I is for the most dangerous flammable liquids, where volatility is a major concern. The defining feature here is that the liquid boils at a relatively low temperature—at or below 35°C—so it can form vapors readily at typical ambient conditions. That high volatility is what drives the stringent packaging and handling requirements for these substances.

High vapor pressure can accompany low boiling points, but it isn’t the single criterion used to identify Packing Group I in this context. A boiling point above 35°C would mean the liquid is less volatile and therefore not characteristic of Packing Group I. While a very low flash point signals flammability risk, the question points to the boiling point threshold as the best descriptor among the given statements.