IMPORTANT

Industry Professionals Discuss Ammonia Refrigeration Safety

by Art Sutherland A

CCENT REFRIGERATION SYSTEMS of Victoria, British Columbia, held an Ammonia Safety Symposium on Nov. 18 at Westhills Arena in Langford, British Columbia, to

review the current state of refrigeration safety in the ice arena industry and to discuss best practices and ways to improve refrigeration safety.

The symposium was well attended by an invaluable

cross-section of industry professionals including engineers, refrigeration contractors, refrigeration instructors, plant operators, safety authority inspectors, first responders, members of the International ASHRAE 10.2 Ice Rink Committee and members of the CSA B-52 Board.

At the time of the symposium, the final report of the tragic

event that took the lives of three people in Fernie, British Columbia, had not been released, and given the fact that two of the attendees were on the investigating team, it was agreed that we would not directly discuss the incident. Following a round of introductions, which emphasized the depth of knowledge in the room, ammonia safety discussion ensued.

Te following input was compiled from feedback from

the participants and is meant as a starting point that industry professionals can expand upon in the future.

In Canada, there is a well-developed ammonia installation

requirement as regulated by the CSA B-52. Te code has a minimum best practice but does not prescribe better practices that can improve safety further. Greater practices can be and should be asked for by the end users if there is a concern.

It was pointed out that while British Columbia has mandatory

operator requirements, other locations in North America, including neighbors as close as Alberta, have none.

Given the fact that the Fernie incident was the first time in

over 100 years that there has been a fatality in the recreational ice industry due to ammonia, it is clear that there is a high standard for ammonia safety. It was indicated that there have been at least three fatalities in facilities that were using the perceived safer A-1 refrigerants (Freon/R-22), emphasizing the importance of safety procedures.

Four of the attendees — the moderator, one inspector, one

engineer and one operator — had felt that they had been in a plantroom ammonia release situation in which they felt in danger. All four experiences occurred during maintenance procedures

12 SPRING 2018

AMMONIA LEVELS TO KNOW

25 PPM/TWA

Time Weighted Average for an 8-Hour Exposure

35 PPM/STEL

Short Term Exposure Limit (15 minutes) 300 to 500 PPM/IDLH

Immediate Danger to Life and Health

when the individuals were not wearing a protective breathing apparatus. Tree of the attendees were in serious situations as a result of large Freon releases. In these cases, however, none of them were aware of the high level of Freon in the room due to its relatively odorless characteristic.

Terefore, as a group, we feel it is imperative that at any time

a person enters the plantroom, he or she have a bite block in their possession. Also, any time maintenance is being carried out involving opening a section of the system, an ammonia mask should be worn during the opening and kept in reach once the system is proved safe. It is important for all staff to know the significance of the ammonia levels displayed on the detection equipment and these levels should be written next to the display.

LEAKS INTO THE BRINE SYSTEM OR CONDENSER

Leaks into the brine system or condenser can be hard to detect as the ammonia readily absorbs into the water. In the event of a large leak, the water could become saturated with close to 40 percent ammonia concentration, which would be hazardous if released into a machine room or confined area. It is recommended that pH sensors be installed on the brine system and the condenser water system. A small ammonia leak would immediately be picked up by the computer control as a high pH reading.

AMMONIA WARNING EQUIPMENT

Regarding warning equipment, there must be an ammonia level display on the detector before anyone enters the plantroom. Tere must be a warning alarm and strobe light inside the plantroom as well.

Additional warning lights and alarms should be installed

in the resurfacer room, operator’s room and manager’s office to provide early warning. Many facilities that have computer control systems also receive warnings on their smartphones. Stacked warning lights that can be viewed from a distance to easily identify threat levels and indicate the presence of other gases, such as propane, are also recommended.

Stacked Visual Warning Light