Water was poured into a drum containing 30 litres of methyltrichlorosilane during cleaning operations in workshop at an industrial establishment. A cloud of hydrochloric acid formed, requiring the hospitalisation of 19 people. A severely effected employee, as well as an adult and 3 children passing near the company, remained under medical supervision as a precaution. A mobile chemical response unit monitored the chemical reaction (hydrolysis) initiated in the drums.