Abstract: At approximately 12:30 p.m. on August 16, 1991, Employee #1, a chemical operator for Crompton & Knowles, was adding nitrosylsulfuric acid, as an intermediate step, to a glass-lined reaction kettle, during the manufacture of Disperse Blue 102 diazo dye. Employee #1 was monitoring the temperature of the reaction, when he noticed it starting to rise quickly. He had started to evacuate the premises, when the reactor vessel exploded. The manhole to the reactor was blown off and the chemical solution contacted Employee #1's arms. Employee #2, a chemical tanker truck operator for an independent trucking company, Conwell & Sons, Inc., was unloading a large shipment of sulfuric acid (not related to the reaction) into a holding tank. Employee #2 was outside the reaction building, 75 ft away. When the manhole cover blew off, chemical solution was spewed out of the vessel and out of the building, and contacted Employee #2's body. Both employees were treated for chemical burns at a nearby hospital and released. An inspection was not opened on Employee #2 because he was a victim of unusual circumstance and had not contributed to the accident in any way.