Hazmat IQ Flame Impingement A Source Of CO? BY STUART WEST, TORONTO FIRE FIGHTER, STATION 145-B
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ne summer day, early on in my career as a Toronto Fire Fighter, my crew and I were handing out information for our annual Alarm for Life Campaign. As my partner and I moved to the next house and approached the door, we could hear the distinct sound of a smoke or CO alarm going off. After knocking a few times it seemed that nobody was home, until suddenly, a woman came running up the driveway. She was quite concerned that something was wrong, as why else would fire fighters be knocking at her door? We assured her that we were just handing out fire safety information, but that we could also hear what sounded like an alarm going off inside her home. She invited us inside and we quickly realized that it was her CO alarm going off, which necessitated a quick sprint back to the truck to retrieve the CO detector. The CO levels were over 100ppm and after investigating, we came to find out that she had been boiling tomatoes on a gas range stove in the basement. The pot was quite large and had seemingly smothered the flame, preventing the proper ratio of fuel to air, resulting in a buildup of CO in her home. Since that experience, I have become a Hazmat Technician and also a Civilian Gas Technician. In my training, I have come to learn that what took place that day is known as Flame Impingement. As fire fighters, we are keenly aware of the dangers of Carbon Monoxide poisoning. At the same time, we are also very familiar with what the common sources of Carbon Monoxide are in residential settings. However, some may not be aware that an object, simply impinging on a flame can also cause incomplete combustion, resulting in the production of Carbon Monoxide. How does flame impingement cause the production of Carbon Monoxide? In the case of gas appliances in our homes, it is critical that excess air be permitted to access the combustion zone to prevent incomplete combustion. When an object impinges upon the flame, that excess air is prevented from participating in the combustion process, and without a proper amount of air to balance with the fuel, the result is incomplete combustion and the production of Carbon Monoxide. Another common example of flame impingement that occurs commonly in residential settings are gas fireplaces. When your Gas Technician commissions the appliance for the first
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