A runaway chemical reaction occurred at Corden Pharma Ltd in Cork on Monday 28th April 2008. The incident resulted in the death of one operator and serious injury to another. The investigation carried out jointly between the Health and Safety Authority and Chilworth showed that the immediate cause of the incident was due to omission of acetone in reactor K6003 prior to Diethylcarbamoyl chloride (DECC) addition during synthesis of the acyloxypyridinium salt precursor to 2-cyano-3-methylpyridine. This resulted in a higher than expected adiabatic temperature rise leading to a two-stage decomposition, firstly of the acyloxypyridinium salt and then of the Picoline-Noxide starting material. The energy of the event was significant and resulted in considerable distortion of the reactor and release of contents at high temperature and pressure. The pressure wave resulted in significant building damage and ejection of debris. The exact reason why acetone was omitted has never been established although, with such a potentially severe consequence, the investigation concluded that more should have been done to eliminate the possibility of human error for this process step. The investigation also highlighted deficiencies in the sites execution of its process safety management systems, particular its HAZOP / risk assessment for this process.

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