🔍 Key Concepts

• Ethylenediamine is a reactive organic base and a water-miscible liquid, not a typical hydrocarbon fuel • Compatibility of different foam types (water foam vs alcohol-resistant foam) with polar/solvent-type liquids • Why some agents (like dry chemical or water fog) are more generally acceptable on chemical/liquid fires

💭 Think About

• First, decide whether ethylenediamine behaves more like a regular hydrocarbon fuel or like an alcohol/solvent in terms of how it mixes with water • Ask yourself which foam types are designed for fuels that do not mix with water, and which are designed for fuels that do mix with water • Think about what happens to a normal water-based foam blanket if the burning liquid is completely miscible with water — does the blanket stay intact or break down?

✅ Before You Answer

• Verify whether ethylenediamine is miscible with water and behaves like a polar solvent • Check which foam type is not recommended for polar, water-miscible solvents because it breaks down on contact • Confirm that dry chemical powder and water fog are generally acceptable on many flammable liquid fires, then focus on which foam type is incompatible