No number accompanies an extinguisher's C rating. The C on the label indicates only that the extinguisher is safe to use on electrical fires. Extinguishers for Class D fires must match the type of metal that is burning. These extinguishers do not use general numeric ratings, but is instead labeled with a list detailing the metals that match the unit's extinguishing agent. Ask your local fire department for advice on the best locations.
Extinguishers require routine care.
Read your operator's manual and ask your dealer how your extinguisher should be inspected and serviced. Rechargeable models must be serviced after every use. Disposable fire extinguishers can be used only once and must be replaced after use. Following manufacturer's instructions, check the pressure in your extinguishers once a month. Follow the four-step PASS procedure.