An Idaho frozen food manufacturer failed to safeguard employees and was unprepared to respond to a potentially lethal release of 1,300 lb of anhydrous ammonia on December 1, 2015, according to the U.S. Department of Labor's Occupational Safety and Health Administration.

OSHA investigators issued 19 serious and two willful citations to Dickinson Frozen Foods Inc. following the hazardous release. The agency fined Dickinson a total of $273,000. An investigation after the incident found dozens of hazards related to emergency response, respiratory protection and process safety management of hazardous materials violations.

Anhydrous ammonia is a colorless gas with a pungent odor that is widely used in agricultural and industrial refrigeration systems. The ammonia vapor severely irritates and can damage the eyes and respiratory tract.