AFFF solution proportions

• A. 100% seawater
• B. 50% seawater 50% AFFF
• C. 94% AFFF 6% seawater
• D. 94% seawater 6% AFFF

Answer: (D)

AFFF solution is made by diluting foam concentrate with seawater to a specific percentage, and that percentage determines how much foam-forming agent is in the finished mixture. For many shipboard firefighting setups, the standard mix for hydrocarbon fires is 6% foam concentrate in water. So the correct approach is to use a solution made of 94% seawater and 6% AFFF, ensuring enough concentrate to create the foam film and blanket needed to suppress the fire.

Using pure seawater provides no foam, while a much higher concentration would waste concentrate and could cause other issues, and a mixture with more concentrate than water isn’t how these systems are designed to operate.