Fire and explosion hazards of chlorine-containing systems

In the chemical industry chlorine is an important compound, produced and used on a very large scale. This paper deals with the fire and explosion hazards of chlorination reactions and the handling of free and bound chlorine-containing systems. Some relevant characteristics will be presented, such as flammability limits, auto-ignition, quenching diameter, burning velocity and detonation limits, especially for the system methyl chloride—chlorine. Autoignition temperatures of systems containing chlorine as an oxidant are usually much lower than the corresponding values in air or oxygen. For example, for methyl chloride the value measured (215°C) is approximately 400 degrees lower than the corresponding value in air. On the basis of the information available and a number of cases illustrating the field of interest, the general case of chlorine-containing systems will be discussed and some consideration given to the safe handling of these systems in a chemical plant, especially in the gas phase.