🔍 Key Concepts

• Combustible vs. flammable liquids and how they are defined in 46 CFR cargo regulations • The system of cargo grades (A, B, C, D, E) and which of those are specifically called "combustible" • Where in the definitions section combustible liquids are separated into specific grades

💭 Think About

• First, recall which grades (letters) are classified as combustible rather than flammable • Count only the grades that are explicitly labeled as combustible liquids, not the entire list of cargo grades • Ask yourself: once liquids are defined as combustible by flashpoint, into how many separate groups (grades) are they split?

✅ Before You Answer

• Verify in 46 CFR definitions that only certain lettered grades are called "combustible" • Confirm that flammable grades are excluded from your count • Make sure you are counting grades, not flashpoint ranges or classes from some other code (like NFPA)