EnergySafe Magazine Autumn 2015, issue 39 | Page 8

08 Latest news Safety warning about butane lunchbox cookers By Jason Treseder, Gas Engineer ESV has issued a warning not to use butane canister or “lunchbox” cookers after a recent investigation found that a number of these appliances are non-compliant and may overheat, catch fire or explode. All non-compliant butane cookers have now been withdrawn from sale and a number of unsafe models are being recalled due to concerns relating to the internal overpressure safety device, which can result in the butane cartridge rupturing if it overheats. What are butane cookers? Butane cookers are small, portable gas cookers that are supplied through disposable butane cartridges. These appliances are portable, inexpensive and are popular for cooking while camping or undertaking outdoor activities. However, this increase in popularity has brought with it an increase in the number of incidents involving these appliances that have been reported to ESV and other gas safety regulatory authorities over the past few years. Investigations into the causes of these incidents have found the use of large pots, frying pans or barbecue plates, or the use of aluminium foil or other activities that result in extra heat being directed onto the gas cartridge are often involved. Extra heat directed onto the gas cartridge causes the pressure in the cartridge to increase. If the heat source is not stopped the gas cartridge can rupture resulting in an explosion and fire. This risk is present with butane cookers as the butane cartridge is located within the body of the cooker and is relatively close to the burner and the cooking vessel. To prevent this serious safety issue all portable butane cookers are tested to ensure under normal cooking conditions the temperature of the cartridge does not increase above ambient. Cookers are required to have an overpressure safety device that shuts off gas flow to the burner when the pressure inside the cartridge reaches an excessive pressure. This overpressure safety device consists of a lever system attached to the gas valve such that when the pressure inside the cartridge exceeds a set value a pin will extend from the valve and cause the gas cartridge to eject. This automatically stops gas flow to the burner and allows the gas to cool down. The pressure at which this device is activated is well below the safe operating pressure of the cartridge and if this device is operating correctly the gas cartridge should never reach a point when it is at risk of rupturing. Due to the number of incidents occurring, a review of compliance was conducted by ESV and other gas regulatory authorities. This review included sample testing of appliances currently on the market to verify the correct operation of the overpressure shutoff device. The review found that a number of appliances were fitted with safety devices that failed to operate correctly, which means when the butane cartridge is overheated the burner can remain on and heat the gas to an unsafe pressure. In extreme cases this can cause the gas cartridge to rupture allowing unburnt gas to escape and ignite, resulting in potential burns and injury to surrounding people. Go to for details of of all the models that are being recalled. If you would like further information, contact ESV on 1800 652 563. lick here to access the full list C  of uncertified products that should not be used