The fire protection industry's two primary extinguishing agents, Halon 1211 and 1301 have both been identified as ozone depleting substances and are being phased out in accordance with the Montreal Protocol.

For some time, the Kidde Graviner development team has been active in monitoring the political, scientific and technical aspects of the Halon issue to obtain the earliest possible information on new extinguishing agents.

For many years, Kidde Graviner and its sister companies have designed and manufactured dry powder systems to meet performance and reliability requirements for off-road and armoured fighting vehicle markets.

The company has undertaken a series of exhaustive trade studies and test programmes on these agents.

Alternative agents such as dry powder, carbon dioxide and water, together with replacement halocarbon agents have been evaluated.

Full-scale trials have confirmed that DXP dry powder formulation developed by Kidde Graviner offers the most cost-effective solution for fighting vehicle engine bays. The trials included evaluation of agent performance against a variety of fuel fires (diesel, oil, kerosene and so on) over a wide range of threats (pan fires, sprayed fuel fires and mixed Class A/Class B fires). Airflow conditions ranging from static to 12 ms"1 in cluttered compartments were tested.

At the heart of the DXP system is a cylinder containing the dry powder, superpressurised with nitrogen and fitted with an appropriate release valve. Pipework connects the suppressant to the distribution system which provides an even dispersion of the suppression agent.

The.new DXP agent does not contribute to ozone layer destruction or global warming. It is comparable with Halon 1211 and 1301 in weight and performance, when used in engine compartments.

Since Kidde Graviner's new dry powder agent is used in minimal quantities and is water soluble, clean-up is readily achieved. The DXP system offers the lowest technical and environmental risk for non-Halon fire supression systems.

In production since 1995. DXP systems are now in service in the UK and four other countries and further deliveries are planned.