On June 29, 2005, an operator was involved in the following maintenance activities in the Chloropyridines Complex at the employer’s chemical manufacturing facility. He was returning a reactor vessel to service and WAS ATTEMPTING TO DO A PRESSURE AND LEAK TEST USING CHLORINE GAS. The pipeline was supposed to be pressure tested with nitrogen gas during the previous shift.
During the test, the employee noticed that a valve leading from the reactor vessel was closed. When he opened the valve, chlorine gas began to escape from a loose downstream flange. About 180 pounds of chlorine was released. Employee #1 returned to close the valve WITHOUT DONNING RESPIRATORY PROTECTION and inhaled chlorine gas. Employee #1 was hospitalized for more than 24 hours for acute chemical exposure. Employee #2, a contractor employee, was escaping from the released chlorine gas and suffered an asthma attack. Employee #2 was treated and released the same day.