🔍 Key Concepts
• Flash point definition and why 80°F / 60°C is an important dividing line in USCG cargo classifications
• Difference between flammable and combustible liquids in 46 CFR (based on flash point ranges)
• How petroleum cargo grades (B, C, D, E) are tied to specific flash point intervals
💭 Think About
• First decide: with a flash point of 85°F, is this liquid legally treated as flammable or combustible? Which side of the key flash-point cutoff does 85°F fall on?
• Then, once you know flammable vs combustible, think about which grade letter (B, C, D, or E) corresponds to that flash point range.
• Compare 85°F to the lower and upper bounds of each grade’s flash point range and ask: which single range does 85°F actually fit into?
✅ Before You Answer
• Verify the exact flash point boundary where USCG changes from flammable to combustible liquid in 46 CFR Subchapter D (Tanker regulations).
• Check the defined flash point ranges for Grades B, C, D, and E in the regulations and note where 85°F lies.
• Be sure you are using Fahrenheit, not Celsius, when comparing to the regulatory ranges.