Rules of the Road: Time to replace halon systems

Mar 2, 2018 by Capt. Jake DesVergers

Rules of the Road: by Capt. Jake Desvergers

Every vessel on the water, from the smallest runabout to the largest tanker, has some type of fire-extinguishing system on board. It may be a portable extinguisher, rolling foam applicator, or a major water sprinkler system. Many ships and yachts, especially those built in the 1980s and 1990s, use the fire-extinguishing medium halon.
Halon is a liquefied, compressed gas.  It leaves no residue and is remarkably safe for human exposure. Halon is rated for class “B” (flammable liquids) and “C” (electrical fires), but it is also effective on class “A” (common combustibles) fires. It has low toxicity, chemically stable compounds that, as long as they remain contained in cylinders, are recyclable.

As readers will recall from their training at marine fire school, four things must converge simultaneously to start a fire. These include fuel, oxygen, an ignition source and a chemical reaction.  Traditionally, to stop a fire, one needs to remove a side of this tetrahedron.  Halon breaks the chain reaction.

Halon has been used for fire and explosion protection throughout the 20th century.  It remains an integral part of the safety plans in many of today’s manufacturing, electronic, and aviation companies. Halon protects computer and communication rooms throughout the electronics industry.  It has extensive applications with military forces.

However, in 1987 the United Nations classified halon as a chlorofluorocarbon.  Through the Montreal Protocol on Substances that Deplete the Ozone Layer, this international regulation stipulated that due to the ozone-depleting potential of chlorofluorocarbons, production and consumption of them should be kept at their 1986 levels. A phase out of these agents started on Jan. 1, 2000.

Accordingly, the International Maritime Organization amended the International Convention for the Safety of Life at Sea to implement the use of alternative fire extinguishing systems. This was to take effect with all new constructions after Oct. 1, 1994. The revision to SOLAS prohibits any new fire installations on existing vessels and prohibits the release of halons into the atmosphere when testing existing systems. A subsequent IMO resolution prohibited the use of all chlorofluorocarbons in any new fire, refrigeration or cooling installation on ships after Nov. 6, 1992.

In reviewing these dates, it is clear that the regulations took effect more than 25 years ago.  So why do yachts still have halon systems? While the worldwide production of halon ceased Jan. 1, 1994, it is still legal in some countries to purchase and use recycled halon and fire extinguishers.

In the United States, there are no regulations mandating the decommissioning of halon systems or portable fire extinguishers. In fact, the Federal Aviation Administration continues to recommend halon fire extinguishers for use on aircraft because of its effectiveness, weight ratio and low toxicity.

In Europe, the use of halon has been banned since 2003. European authorities have stated that the supplying of a non-European Union-flagged ship in a European port with halon is considered an illegal export. Because of this status, the refilling of halon systems with other than the original halon is not possible.

In Australia, with certain exceptions for the aircraft industry, it is illegal to own or possess any halon-based fire protection system. This applies to both domestically registered and foreign-flagged vessels visiting the island continent.

With the decreasing availability of recycled halon, the impossibility to replenish a halon system once used, and the phasing-out deadlines for some flag administrations, yachts should begin planning for a replacement system.

The fire suppression industry has developed alternative clean agents that pose less threat to the ozone layer. Two classes of agents have emerged as suitable replacements: Halocarbon-based agents are carbon-based compounds that extinguish fire primarily via the absorption of heat, such as in a halotron system; and inert gas agents are based on the inert gases (i.e., nitrogen, argon, carbon dioxide) and extinguish fire via oxygen depletion.

Installation of a new system is not an overnight fix.  Often, the new system must be reviewed and approved by the yacht’s flag administration and/or classification society. Advanced planning is key to keeping the yacht running without delays and uncontrollable expenses.

Capt. Jake DesVergers is chief surveyor for International Yacht Bureau ( Comments are welcome below.


About Capt. Jake DesVergers

Capt. Jake DesVergers is chief surveyor for International Yacht Bureau (IYB), an organization that provides flag-state inspection services to yachts on behalf of several administrations. A deck officer graduate of the U.S. Merchant Marine Academy at Kings Point, he previously sailed as master on merchant ships, acted as designated person for a shipping company, and served as regional manager for an international classification society. Contact him at +1 954-596-2728 or

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