|This article appeared in the AACA Judges newsletter and was written by Randal Stone - then Vice President Judges Administration.
The 2008 Judging Guidelines, approved by the Class Judging Committee, will have the following new wording for the improved Fire Extinguisher rules.
The fire extinguisher must be UL listed or equivalent and fully charged. The minimum for all vehicles is a UL Type 1-A:5-B:C. The extinguisher need not be permanently mounted, but must be clearly visible and readily available.
Now I know this sounds complicated but it is really quite simple. The following chart will help you in remembering what Classes A, B and C are all about:
Fire extinguishers with a Class A rating are effective against fires involving paper, wood, textiles and plastics. The primary chemical used to fight these fires is monoammonium phosphate, because of its ability to smother fires in these types of materials.
Fire extinguishers with a Class B rating are effective against flammable liquid fires. These can be fires where cooking liquids, oil, gasoline, kerosene, or paint have become ignited. Two commonly used chemicals are effective in fighting these types of fires. Monoammonium phosphate effectively smothers the fire, while sodium bicarbonate induces a chemical reaction which extinguishes the fire.
Fire extinguishers with a Class C rating are suitable for fires in "live" electrical equipment. Both monoammonium phosphate and sodium bicarbonate are commonly used to fight this type of fire because of their non-conductive properties. Class C fires are only for active or live electrical circuits. If the power is shut off and the fire remains active the "Class" would revert to the type of material burning (Class A or B).
When you see a numeric beside the A or B it is showing you the average square footage the extinguisher would be effective against. Example 5 — B: flammable liquid fire no greater than 5 square feet in area.
Remember when you were young and your mom put baking soda in the refrigerator? She put it there to reduce odors and for a while it would work. After a period of time you had to stir it up, as it would settle into a seemingly solid lump and no longer work. Your dry chemical fire extinguisher is the same way. Over time they will settle and potentially not work when you need them the most! How do we solve this problem? Easy, shake them up every now and then. You will feel the solid in the bottom break up and become loose again. Easy to do but very important for your fire extinguisher to be ready when you really need it.
The A:B:C fire extinguishers can be found at all the major retailers for home repair and improvements. Remember; 1-A:5-B:C is the minimum. I have 1-A:10B:C in my home and shop as they seem to be more readily available. Total cost for this larger size is in the $20 range and the size is very close to that of a roll of paper towels.