be found in fires involving no accelerant. This is particularly true in cases of full room involvement. The properties of some ignitable liquids make them dangerous fuels. Many ignitable liquids have high vapor pressures, low flash points and a relatively wide range between their upper and lower explosive limit. This allows ignitable liquids to ignite easily, and when mixed in a proper air-fuel ratio, readily explode. Many arsonists who use generous amounts of gasoline have been seriously burned or killed igniting their fire. Available combustibles Common household items and objects can accelerate a fire. Wicker and foam have high surface to mass ratios and favorable chemical compositions and thus burn easily and readily. Arsonists sometimes use large amounts of available combustible material rather than ignitable liquids in attempts to try to avoid detection. Using large fuel loads can increase the rate of fire growth as well as spread the fire over a larger area, thus increasing the amount of fire damage. Inappropriate amounts and types of fuel in a particular area can indicate arson. Whether available combustible materials constitute an accelerant depends on the intent of the person responsible for their use. Rubber vulcanization The use of accelerators and activators lowers the activation energy of vulcanization reaction to 80-125 kJ/mole from 210 kJ/mole which is necessary if we use sulfur alone. Accelerators and activators break sulfur chains. Accelerated sulfur vulcanization systems require only 5-15 sulfur atoms per cross-link as compared to 40-45 S atoms/crosslink for a non-accelerated sulfur vulcanization. There are many accelerators available for the vulcanization of rubber. That is because there is a wide range of rubber articles on the market with a wide variety of properties. For instance in a car tire alone there can be already up to eight different rubber compounds, each with specific properties. For instance the tread in a typical passenger car tire consists of a mixture of SBR (styrene-butadiene rubber) and BR (butadiene rubber). This rubber should have high abrasion resistance and high grip on both dry and wet roads. The side wall of the tire should have a high flexibility, meaning that it should resist many flexings during the running of the tire without cracking. It consists normally of a mixture of natural rubber and butadiene rubber. Inside the tire there is a rubber compound with as major function the adhesion between rubber and the steel cord of the belt. It