Failure to remove ammonia from refrigeration system primary cause of fatal Kamloops leak: Technical Safety BC

A failure to remove ammonia from a refrigeration system was the primary cause of an accident in Kamloops, B.C., that killed on person, according to an investigation by Technical Safety BC.

The incident happened on May 26, 2022, at an ice making facility in the Mount Paul Industrial Park located on Tkemlúps te Secwépemc reserve in Kamloops. It led to multiple exposures, a local evacuation and the temporary shutdown of local businesses.

“The investigation concluded that the ammonia release occurred when a ball valve holding back pressurized ammonia for the entire system was opened, however those working on the disassembly understood the system to have been previously emptied,” Technical Safety BC said in the report. “Several contributing factors led to this incident, including miscommunication, staffing changes, and failing to involve a licensed refrigeration contractor to conduct a complete assessment for the presence of ammonia.”

Contributing factors

In addition to the failure to remove ammonia, the agency listed a number of contributing factors:

• Following equipment shutdown, there was an incorrect understanding that ammonia had been previously removed.
• After discovering ammonia, assessments were ineffective in determining the location and quantity of ammonia.

It noted there was no failure with any component or assembly within the ammonia system.

“The quarter turn ball valve resulted in the release of ammonia being rapid and uncontrolled,” it said.

It said that, on May 26, there were between 1,300 and 1,645 pounds of ammonia “likely” released into the atmosphere.

Key learnings

Leading up to the incident, workers unfamiliar with ammonia relied on the guidance of previously qualified refrigeration mechanics, Technical Safety BC said.

“This resulted in the work continuing when it likely would have otherwise been stopped,” it said.

It noted that only professionals with the necessary skills and knowledge should be conducting activities with hazardous work.

“This principle applies throughout the life cycle of regulated systems, including the stage of dismantling and decommissioning,” it said. “Licensed contractors must validate that ammonia and oil have been removed from a system and that equipment is ready for disassembly and transportation.”

Recommendations

Technical Safety BC issued three recommendations in the wake of its investigation:

Recommendation 1: to owners and/or managers of refrigeration systems:

• It is recommended that when planning for and facilitating the final shut down and disassembly of refrigeration equipment, owners and managers directly engage a licenced contractor to validate:
  • Ammonia and oil are removed.
  • Equipment is ready for safe disassembly and transportation.

Recommendation 2: to persons who hold or previously held a technical qualification:

• It is recommended that persons who previously held, or currently hold a technical qualification do not counsel unqualified persons to do regulated work. Qualified persons are reminded that the Safety Standards Act and Regulations prohibit unauthorized persons from doing regulated work unless they are being supervised by a qualified person.

Recommendation 3: to the Canadian Standards Association (CSA):

• It is recommended that CSA adopt or develop requirements for the dismantling, disassembly and/or decommissioning of refrigeration systems and equipment.

You can view the full report here.