I've had two experiences with things blowing up unexpectedly. The first was in 1979 in Mississauga, Ont., when a train carrying propane and other gasses derailed about a mile from my house. The rail cars exploded, creating huge fireballs in the sky and sending toxic fumes into the air. The accident forced the evacuation of 200,000 people from the area, and we were not able to return until several days later.
The second jolt happened about 10 years ago, when the house across the street from mine blew up. That time, the cause was a contractor who hit a natural gas line with his backhoe, causing a leak in the basement of the house. Two houses were destroyed and many more damaged.
These explosions, and the one in Toronto August 10, which resulted in two deaths and required thousands of residents to flee from their homes in the middle of the night, are stark reminders that the volatile gases we rely on every day can also be very dangerous.
Homeowners use propane for everything from heating their homes and fueling appliances to cookouts in the woods. When storage facilities and systems are properly maintained and used correctly, propane is safe. The Propane Gas Association of Canada (PGAC) says propane tanks are 20 times more puncture proof than conventional gasoline tanks. It says propane is stored and used in sealed containers and fuel systems, and is only transferred from one container to another by trained personnel. In the event of a leak, says the PGAC, propane "readily vaporizes and dissipates into the atmosphere."
But accidents do happen. When a propane tank is exposed to heat, pressure builds up inside the tank. There are valves to release the pressure, but when they don't work, it creates a boiling liquid expanding vapour explosion. This is what happened in Toronto. The explosion created shockwaves that broke windows for more than a kilometer around the site, and damaged hundreds of homes. Shrapnel flew high in the air and some of the tanks took off like rockets.
In the aftermath of the explosion, there has been extensive testing for asbestos on the homes and land around the explosion site. Lawsuits have already been initiated, and both the municipal and provincial governments have pledged to review their laws and regulations regarding propane tank storage.
For homeowners, it's a timely reminder to review your own safety procedures for handling propane.
If you use propane for heat or for indoor appliances and if you think you smell propane, extinguish all smoking materials and open flames and get everyone out of the house or RV immediately. Do not touch electrical switches. Call 911 or the propane supplier.
Propane smells like rotten eggs or boiling cabbage. It's heavier than air and gathers in low-lying areas.
Propane cylinders should be stored outside in a well-ventilated and secure location, says the PGAC. Never store them in an enclosed area or indoors. Keep you head away from the valves on your tank or cylinder. If propane comes in contact with your skin or eyes, it can cause severe frostbite, says the association.
Propane tanks and cylinders must be stored in an upright, vertical position, well away from any heat sources. Another tip is to make sure your tank is painted a white, aluminum or other reflective colour. Rusty or dark-coloured tanks may absorb heat and cause pressure to build in the tank, which could lead to a discharge from the pressure release valve.
For barbecue safety, each year before using your unit for the first time, make sure the tubes between the gas line and the burner are cleaned out. Replace any hoses or burners that are worn or rusted. Always open the barbecue lid before lighting it.
Check the cylinder connections for leaks every time you replace it and before the first use of the season. To check the connections, use a solution of 50 per cent liquid soap and water. With the barbecue knobs off, turn the valve on the tank one turn. Use a cloth or brush to wipe the solution onto all hose connections, and watch for growing bubbles that indicate a leak. Turn the valve off again while tightening the connections.
Each propane tank has a date stamped on the collar. By law, if the tank is more than 10 years old, it cannot be refilled.
When transporting a tank after filling it, take it home immediately and don't leave it in the vehicle. Make sure the area is ventilated and that the cylinder valve is closed and plugged or capped.
The PGAC says that Canada produces nearly five per cent of the world's supply of propane and uses about one-third of that domestically, exporting the rest to the United States. It produced 11 billion litres of propane in 2006.