The drive to find alternative fuels to replace such hydrocarbons as diesel and petrol has resulted in a plethora of different fuels-few of which are commercially available in significant quantities. As fuels, by their very nature, must be flammable, the fire, explosion and ignition properties will need to be known. Types of alternative fuels available are described and their ignition and explosion hazards with reference to existing commonly used fuels are discussed. The properties of 13 alternative fuels are given. Of all these alternative fuels, almost all have properties which are similar to those of existing types of fuels, and therefore the technology required to handle them is already well known and available. Hydrogen is the one exception-its ignition and combustion properties are quite different from those of conventional fuels, and hence the specific difficulties and hazards associated with the use of hydrogen are highlighted. Much existing technology is not applicable to hydrogen and there are many areas where adequate knowledge or data is not available. The area of most concern is that hydrogen appears to be prone to ignite spontaneously when released from high pressure, but there is as yet no rigorous scientific explanation for this. Further work is required to obtain greater knowledge of the properties, behaviour and safe use of hydrogen, as this is most likely to be "fuel of the future". (c) 2008 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.