When the boiling point is less than or equal to 35°C (95°F), then the flammable liquid is assigned to Packing Group 1.

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

Answer: (C)

Packing Groups for flammable liquids are based on how volatile and hazardous the liquid is. If a flammable liquid boils at a temperature at or below 35°C, it can generate flammable vapors easily at room temperature, making it highly dangerous to transport. That level of hazard places it in Packing Group I, the highest danger category, which comes with the strictest packaging and handling requirements. So the statement "Boiling Point <= 35°C" directly corresponds to the criterion for assigning Packing Group I. If the boiling point is higher than 35°C, the liquid would fall into a lower packing group (II or III) depending on other data like flash point; flash point or vapor pressure alone don’t alone specify PG I in this rule, though they influence the overall classification.