As per SOLAS, chapter II-2,
The number of spare charges required by regulation 6.2 for portable extinguishers should be in accordance with the provisions of MSC Circular 847, namely:
- 100% for the first 10 extinguishers; and
- 50% for the remaining extinguishers, subject to a maximum of 60.
- Additional extinguishers of the same type and capacity should be carried in lieu of spare charges for any extinguishers which cannot be charged on board ship.
- Instructions for recharging extinguishers should be carried on board ship and refills should be of a type approved by the manufacturer of the extinguisher.
- If the loss of gas from a carbon dioxide extinguisher or propellant bottle of any other type of extinguisher exceeds by 10% of the original charge as stamped on the extinguisher or bottle, then extinguisher or bottle should be recharged. Any extinguisher or bottle which has excessive external corrosion should be replaced.
- In surveying the safety equipment on a vessel classification societies should verify that:
- The manufacturer’s instructions for recharging extinguishers are on board;
- The extinguishers have been inspected and maintained in accordance with the manufacturer’s instructions and the foregoing requirements;
- Records of inspections, maintenance and pressure tests are maintained