🔍 Key Concepts
• USCG portable fire extinguisher classifications (letter = type of fire, Roman numeral = size/capacity)
• The kinds of fires a Class B extinguisher is designed for (what burns in a Class B fire?)
• Typical sizes/capacities that fall into size I vs size II for marine extinguishers
đź’ Think About
• First, identify what type of fire a "B" extinguisher is meant to fight and which of the listed agents can be used on that type of fire.
• Next, think about how the Roman numerals (I, II, III, etc.) relate to the amount of extinguishing agent, not the weight of the whole extinguisher.
• Compare the approximate capacities of a 2 lb dry chemical, a 4 lb CO₂, and a 2-1/2 gallon foam extinguisher to the typical minimums for a size II unit.
âś… Before You Answer
• Verify from a marine firefighting reference which minimum capacities correspond to a size B-I vs B-II extinguisher.
• Check which of the listed extinguishers would meet or exceed the minimum capacity for B-II, rather than just being any Class B extinguisher.
• Confirm that you are not confusing agent weight (pounds of chemical or gas) with rating/size classification (B-I, B-II, etc.).