OSHA said a worker at the plant received medical treatment and missed one month of work after inhaling chlorine gas. OSHA did not fine the company, but DuPont contested the violation, OSHA said.
The penalty came after a National Labor Relations Board ruled against DuPont for refusing to provide its workers' union with information about where hazardous chemicals had been spilled or contaminated an area. DuPont allegedly blocked union health inspectors from examining the plant in 2002.
OSHA said DuPont also failed to report 117 on-site injuries in 1997 and 1998 at its Seaford, Del., plant.