Portable Fire Extinguishers

How the extinguishers work

A stored-pressure extinguisher holds its agent and expellant gas in one shell, with a gauge showing the charge. A cartridge-operated extinguisher keeps its gas in a separate cartridge and pressurises the shell only when you strike the plunger. Cartridge units cope better with heat and vibration on exposed decks and are easy to recharge on board. CO2 extinguishers hold liquefied gas at high pressure in a seamless cylinder with no gauge, so you check them by weight.

Agents and where each goes

SOLAS chapter II-2 regulation 10.3 bars CO2 extinguishers from accommodation spaces, where a discharge in a cabin can cause asphyxiation. Wheeled foam units of 45 L and 135 L appear in SOLAS rules for machinery spaces.

Key specifications

Chapter 4 of the FSS Code asks for at least 5 kg in powder and CO2 hand-held units and at least 9 L in foam units. Every extinguisher must match the fire-fighting capability of a 9 L fluid extinguisher at minimum.

Standards and intervals

IMO resolution A.951(23) gives the guidelines for marine portable extinguishers, and MSC.1/Circ.1432 sets onboard maintenance. The intervals that matter when you buy used stock are these:

• Annual inspection and service by a competent person
• A test discharge every five years of at least one extinguisher of each type and each year of manufacture
• A hydrostatic test of every shell and propellant cartridge at intervals not over ten years
• Spare charges for 100 percent of the first ten extinguishers of each type and 50 percent of the rest, under SOLAS chapter II-2 regulation 10.3

SOLAS has banned new halon installations, so a halon extinguisher has no place on board and should go to a licensed recovery facility.

Failure modes and inspection

• Internal corrosion in water and foam shells, found at hydrostatic test or by internal inspection
• Caked or compacted powder in units stored without movement
• Corrosion and dents on the shell, damaged threads and collar
• Gauge reading low, or a CO2 unit more than 10 percent under its marked weight
• Cracked hoses, blocked nozzles and missing safety pins or seals
• Cartridges past their test date or under weight

Documentation

• Approval certificate for each model
• Manufacture date and last hydrostatic test stamp on every shell
• Annual service label or record with the service company's name
• Weight records for CO2 units and cartridges
• Matching spare charges, with batch dates

Integration and compatibility

Spare charges and cartridges must match the extinguisher model exactly. Mixing brands breaks the approval and can mean the wrong expellant pressure. Brackets for exposed decks need weather covers and must hold the unit against vessel motion. Check foam concentrate in foam units against the PFOS ban and any regional PFAS rules for your unit.

Surplus, used and recertification

Unused surplus with recent manufacture dates is the easy choice. Used extinguishers can return to service after a full service, but value drops as the ten-year test approaches. A CO2 extinguisher in good condition is usually worth a hydrostatic test. A rusted or dented shell is not worth the test fee. Naventr can pass your questions on test stamps and approvals to the Seller. Kidde and Minimax are well-known makers of marine extinguishers. For fixed protection of the same spaces, see fixed fire suppression.