On December 19, 2022, at approximately 11:10 a.m., an accidental release of 22,000 pounds of anhydrous ammonia occurred from the NH3 refrigeration process at a food processing facility in Norwood, Massachusetts. Exposure to the toxic ammonia vapor fatally injured one contract worker and seriously injured another contract worker. In addition, the release caused about $4 million in property damage.
The facility had hired a contractor to install an electrical (ceiling-mounted) heater to replace an existing leaking steam heater that provided comfort heating inside the facility’s ammonia refrigeration machinery room. The work plan included using a scissor lift to access the installation area. At the time of the incident, two (2) contract workers were on the scissor lift to install the electric heater. While the scissor lift was in an elevated position, the lift was moved forward and then upward, impacting an ammonia refrigeration system valve.