Vinyl Chloride Explosion
Two vinyl chloride polymerization reactors were being operated by the same team of operators. Reactor 3 was in the cool down and dump phase of the process, and reactor 4 was nearly full of monomer and in the polymerization phase. The foreman and three employees set to work to discharge the contents of reactor 3, but in error they opened vessel 4 instead. The gaseous vinyl chloride monomer just in the process of polymerization burst out of the vessel, filled the room, and shortly afterward exploded violently, presumably ignited by a spark from an electric motor or by static electricity generated by the escaping gas. This accident resulted in four fatalities and ten injuries in and around the plant. The accident could have been prevented with better operating procedures and better training to make the operators appreciate the consequences of mistakes. Modern plants use interlocks or sequence controllers and other special safeguards to prevent this type of error.