General lessons to be learned
Lessons from major accidents in the chemical industry

The accidents considered in this article, and the two processes in which well-identified runaway reactions are known, demonstrate the value of a good knowledge of the chemistry involved.

A study of the literature on these processes can certainly contribute to accident prevention. Particular attention should be paid to possible or frequent process drifts, such as :

• absence of agitation;

• too long a residence time at process temperature;

• the entry of coolant or washing liquid into the process.

Secondary reactions occurring in the event of process drift must be taken into account. Abnormal toxic products of secondary reactions are obtained, and reaction exothermies can be greatly increased by the heat of reaction of...