An explosion occurred in a solvent recovery plant processing acetone of an industry manufacturing cellulose acetate. During welding repairs on a disabled vessel connected to a duct, a vapours leak occurred and ignited by a spark, the flame propagated back inside duct causing an explosion but not following by a fire. Ten people are intoxicated and fish mortality is observed. The explosion caused major structural damages to the plant and enclosing buildings. Windows were broken up to 100 metres.

Because of a blanking plate not gas-tight fit, the vapours leak occurred. Although operating procedures have been revised, they were inadequate for repair operations.