Ammonia: How risky is the gas that creates winter fun?
Most ice rinks in N.L. use ammonia in their refrigeration systems
Hockey, figure skating and curling season is upon us, and thousands of people will be heading to ice rinks to enjoy winter sports over the coming months.
For the most part, the ice in those rinks is made thanks to ammonia, a compound commonly used in mechanical refrigeration systems.
A leak can be deadly. That's what took the lives of three men at a hockey arena in Fernie, B.C. in mid-October.
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Steve Beckwith has been working around ammonia for more than 40 years. He is currently the manager of building operations for the biggest rink in the province, Mile One Centre.
"For me, I feel quite safe," said Beckwith.
According to Service NL, which oversees Occupational Health and Safety, ammonia exposure in excess of the allowable limit (25 parts per million or ppm) can cause headaches, coughing and difficulty breathing.
Prolonged exposure to high concentrations can lead to pulmonary edema — an accumulation of fluid in the lungs — which can be fatal.
All the rinks in N.L. fall under Occupational Health and Safety Act regulations, which require annual inspections of compressors and other refrigeration equipment.
"Every five years, we have to change out our safety valves. That is a requirement by law," said Beckwith.
Beckwith can't speak for every rink in the province, but he said they are governed by the same regulations, and even a small amount of ammonia in the compressor room should trip the emergency response system.
"Once it hits 25 ppm, an exhaust fan will come on. It will start exhausting any ammonia fumes out of the building immediately," said Beckwith. "I'm here now seven years. I've yet to smell ammonia out in the corridor."
However, Beckwith said small leaks are a normal part of operations.
"The operator has to, once a week, go in and drain so much of the oil off. So the minute he drains it, the ammonia is contained in the oil. That's enough that the alarms will go off, the light will flash," he said.
Even with the safeguards, it's clear there is a risk.
51 of the 60 ice rinks in Newfoundland and Labrador use ammonia as the coolant in their refrigeration systems. The remaining nine use another gas, Freon, which is considered a safer compound.
Ammonia versus Freon
"Ammonia is very hazardous," said Don Byrne, deputy fire chief for the St. John's Regional Fire Department.
But, because of regular inspections, Byrne doesn't think the public has much to be concerned about.
"If you go to any of the arenas around here, and look at the housekeeping around those arenas, you'll see that most of these are very well kept, and that extends right into the maintenance of their equipment," said Byrne.
Byrne said that while ammonia is more of a risk to life than Freon, an ammonia leak can give itself away because of its pungent smell. Freon is odourless.
And while Freon is safer than ammonia, it can still affect your respiratory system.
"Every gas has a lethal dosage," said Byrne.
Byrne said Freon is a more expensive coolant than ammonia, and it damages the environment.
"That's why Freon isn't utilized as much as ammonia. Ammonia doesn't cause any problem to the ozone layer."
"One of the reasons we use ammonia is because it is one of the best refrigerants you can use because of efficiency," said Ken Baker, chief engineer at Mile One.
"So that means a lower cost to run, plus a lower cost of installation at the beginning."
Evacuation plans in place
Beckwith said that if there was a catastrophic failure of the system — a leak of 250 ppm of ammonia or greater — emergency response would snap into place, and the compressor room has inner and outer doors to seal in the gas.
"If [the engineer] hasn't identified the root cause of the leak and he is unable to isolate it, security, the ushers, all our staff, all of our people have been trained in emergency preparedness and evacuation plans," he said.
"We have a comprehensive evacuation plan here at Mile One Centre, " added Tammy White, safety coordinator.
"Should the need ever arise, Mile One Centre would evacuate in minutes."
Occupational Health and Safety does not require an emergency response plan for Freon because it is seen as much less hazardous that ammonia.
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