In a ketone-colors manufacture, a human error during the mixing of chemical released toxic gases which intoxicated 7 persons.

The worker erroneously added water to the mixture. He realised his mistake upon noticing a “milky” aspect and closed the feeding valve, but the unwanted reaction had started. The runaway reaction increased the pressure inside the reactor and caused the explosion of the glass-pipe which leaded the vapours to the washing tower ; 18 kg Phosgene, 525 kg Chloroform, 4 kg Hydrochloric acid and 120 kg Micheler’s Ketone (as Chloride) were emitted. The fire brigade, equipped with self-breathing apparatus, ventilated the unit and decontaminated with ammonia water. The sucked off atmosphere was abated in a washing column with soda lye.

The supply speed of N.N-Dimethylaniline was reduced by a flow limiter, to limit the pressure rise in case of a reaction with water. The operating pressure of the safety valves will be reduced (from 6 to 2,56 bar). The feeding design of the reactor was modified : Water and Dimethylaniline have separated feed lines.