Fire extinguisher useful in fighting fires with a particular group of fuel. Specifications for fire extinguishers are set out in the standard AS/NZS 1841, the most recent version being released in 2007. All fire extinguishers must be painted signal red. Except for water extinguishers, each extinguisher has a coloured band near the top, covering at least 10% of the extinguisher's body length, specifying its contents. In Australia, yellow (Halon) fire extinguishers are illegal to own or use on a fire, unless an essential use exemption has been granted, this is due to the ozone-depleting nature of halon. According to the standard BS
Chubb Fire 1912–1918 The North Metropolitan Electric Power Supply Company carried out a series of stringent tests on the 'Petrolex' extinguisher and informed Read and Campbell that, 'I have never seen any fire extinguishing appliance that seemed as well suited and effective for dealing with fires in Electrical Stations'. Further patents were granted in France and Brazil during this period. In 1914, foam compound was registered in Great Britain. Read and Campbell introduced their 'Rocsuds' which was an early form of foam extinguisher. The contents were, amongst other things, saponin, derived from the roots of soapwort, sodium bicarbonate, extract of vegetable syrup