While the extinguisher may work, as it says on the inspection tag, “Void 1 year from Mo. Punched.” At a minimum, fire extinguishers must be visually inspected monthly, with a maintenance check done annually. Rechargeable fire extinguishers require more in-depth inspections every six years. This involves conducting a hydrostatic test, which requires the fire extinguishers to be emptied, placed under water and subjected to pressures exceeding their ratings.