Understanding Fire Key to Avoiding Carbon Monoxide Disasters
Avoiding carbon monoxide disasters from storms requires an understanding of the principles of fire: adequate oxygen is needed for the flame and exhaust gases must get outside. CO can be deadly before you smell fire.
Another series of bad storms, another round of carbon monoxide deaths. Why does this keep happening? There is much that could be said about the political/policy issues that surround climate change but regardless of cause, that our weather events are becoming more severe is indisputable. When Mother Nature wants to disrupt our industrial world, she continues to prove capable.
A month ago, we would have thought that the big cause of that disruption was tied to power transmission. Windstorms knock down power lines, the power goes out. What Texas has shown us is that not just the transmission of power is vulnerable, but also the generation. Add ice, wind and cold and suddenly people who have never given a minutes thought to how to generate enough heat to survive, are making do with unconventional solutions. In the Dallas Morning News story, the process of sorting out how many people died as a result of the Texas storms is complicated, and includes road accidents, hypothermia and carbon monoxide poisoning. https://www.dallasnews.com/news/2021/03/01/will-texas-ever-figure-out-how-many-people-died-in-the-winter-storm/ While it seems like a can’t win dilemma, risking CO poisoning should never be the choice. CO can kill quickly but disables dozen’s more than it kills.
Carbon Monoxide Disasters from Improvisation
All of these make-do solutions comes with risks, risks that the poor understanding of combustion, leave people vulnerable to CO poisoning. To help people understand the numerous warnings that come with natural disasters, we felt it would be beneficial to review how CO gets inside the air we breathe and why even at the risk of freezing to death, you cannot risk unconventional ways to warm inside air.
When something burns, the technical term for that is combustion. In combustion, for the carbon in fossil fuels oxidizes. When the carbon in fossil fuels mixes with oxygen, it creates the heat and energy which powers the industrialized world. The C atom (carbon) combines with the O (oxygen) atom to create CO2 (carbon dioxide) and water, H2O, making water vaper. This is cycle of life on our planet, with plants then pulling in the carbon atom in the CO2 to create plant matter and expelling back into the O2 for animals, including humans, to breath. When combustion is incomplete (incomplete combustion) the carbon dioxide molecules which plants need becomes carbon monoxide, CO, a potentially lethal molecule. What makes carbon monoxide so toxic is that it replaces oxygen in our blood (technically binds with hemoglobin), without any clear warning of its existence because it is while odorless and colorless.
Carbon monoxide is the number one cause of poisoning deaths in the world. Deaths are higher outside of the United States because much of the world does not have central heat like in the U.S. What happened in Texas in February of 2021 a result of the break down in the way in which people heat their homes. As generally Texas is a mild climate, electric and space heat is used far more than in colder places in the country. But in February, Texas got as cold as it typically might in the Midwest. Failure to plan for that cold, even though the risk has been well understood for at least a decade, is the overarching cause of the disaster.
Carbon Monoxide Disasters more than Deaths
In the United States, for every person who dies, there are likely more than 45 times that number who survive after getting treatment for CO poisoning. Some of the best epidemiological research on CO survivability come from a study done on the impact of portable electric generators by US Consumer Products Safety Commission’s. That research showed 751 CO deaths versus were 8,703 CO injuries seen in emergency departments. In addition, that study also found that 25,400 CO survivors were seen outside of the ER. Thus, there were 34,103 treated compared to the 751 CO deaths, 45 times as many. That may actually under-estimate how many people likely survive carbon monoxide poisoning as the probability of death from generators is much higher than from other causes. In the generator death cases the ambient air CO levels are much higher because generators put off nearly 100,000 ppm in their exhaust. [1] The U.S. government CDC estimates that 400 people die annually from carbon monoxide poisoning in the U.S.,.[2] Portable generators and furnaces are biggest contributors.
Thus if the death toll in Texas from CO is ultimately determined to be of a magnitude of plus or minus 50, that likely means more than a 1,000 may have suffered permanent brain damage from this one winter storm event. And the problems are not just in Texas. Most of the southeast had similar problems, if not on the scale of Texas.
Are any of the poisonings avoidable? Of course. Let’s start with a simple one. Iced up chimneys on commercial buildings. Hot air goes up chimneys, so they are not expected to freeze. But if it is cold enough (see Polar Vortex in Michigan in 2019) or there is ice, the heat coming out of the chimney may not be hot enough to prevent the ice from building up. Think of it like a defroster on your car. Generally, the defroster keeps condensation and ice from building up on your windshield. But that may not work in an ice storm. It becomes especially troublesome if you keep turning off the defroster. Well a commercial boiler rarely runs constantly, especially one that might be used solely for hot water for showers and laundry. If there is ice falling, that is going to build up in the cycles when the boiler isn’t firing. When the boiler kicks back on, the ice if it melts at all, it may only partially melt.
An iced up chimney is an obstruction to the flow of exhaust out that chimney. If the exhaust can’t go all the way out the chimney to the outside air, it will back up into the building. Counterintuitively, it is more likely to back up into the crawl space underneath the roof, than back into the boiler room. While the boiler room may have a CO detector, as the rooms on the top floor may not. The result: carbon monoxide poisoning with the only warming, a human being getting sick.
Another truly dangerous storm related phenomenon is the use of portable electric generators. Most people are smart enough to not put the generator in the basement but putting it in a garage or within 20 feet of a window can also cause serious levels of CO. Opening the garage door or a window won’t prevent CO poisonings. Any level of CO above alarming levels, can cause permanent brain damage. The higher the levels, the longer the levels exist, the worse the poisoning will get. 300 plus levels can kill. Generators are putting off nearly 100,000 ppm so even if diluted with some outside air, they will still be deadly. What doesn’t kill can severely disable, dozens of times more people.
I have often argued that generators should come with cords that are at least 20 feet long, to make the point that they can’t be used within 20 feet of a dwelling.
Combustion Air Problems create Carbon Monoxide Disasters
One of the reasons poisoning deaths are so high in Asia is that in many places they still use charcoal to heat dwellings. That phenomenon occurred in the United States in February. From the Dallas Morning News: “If a family is found in the living room around a grill.” Grills are meant to be used outside, where there is adequate ventilation and unlimited oxygen for the combustion. As explained above, if there is not enough oxygen for the amount of fuel that is to be burned, two things can happen: the fire will go out, or it will continue to burn with incomplete combustion. A fire going out is far less of a problem than incomplete combustion. Incomplete combustion causes smoke and more dangerously, the creation of CO instead of CO2. Smoke smells and it may be visible, thus if the primary by-product of incomplete combustion is smoke, people will be warned. But smoke often doesn’t begin to be noticeable until CO in the exhaust gets to 4,000 to 5,000 ppm. Human’s noses are sensitive enough to smell it at lower levels. Dogs and other pets often warn of CO events because they can smell smoke at lower concentrations of CO. Humans can die before our noses will smell the smoke. This is why CO detectors are so important, because we can’t smell the CO.
Ovens and Stoves Need More Combustion Air
Warnings often include not to use a gas stove or oven to heat during power disasters. A first reflex when electric heat is out is to turn to gas burning appliances in a house. While this warning is given, reasonable explanations rarely follow. Why is it dangerous to use an oven to heat when it isn’t to bake? There are a couple of explanations, both which likely relate to how the oxygen gets to the flame. The first is a simple one: depending on how airtight the house is, there may simply not be enough oxygen inside the house to keep the oven/stove tops on continuously. A simple example may help: A candle can burn continuously in almost any indoor space without running out of oxygen, but if you light enough candles, and burn them for long enough, perhaps the oxygen is used up. A stove top uses a lot more fuel than a candle. All of the burners on a stove going at once, uses that much more oxygen. That oxygen has to come from somewhere. Houses have been made progressively more airtight to make them more energy efficient. But a perfectly sealed house may run out of oxygen if there are too many appliances using up the available oxygen.
People of course are fuel burning appliances too. Too many people, too many candles, not enough fresh air can equal of deficiency of oxygen. A deficiency in oxygen leads to CO.
The other concern with ovens is that they may be designed to only burn efficiently with the over door closed. With the oven door open, it may disrupt the flame in such a way to make it burn inefficiently. All burners are designed to burn with a predictable intake of oxygen. If the fresh air is coming from an unpredictable direction, it may interfere with the flame (much like blowing on a candle does) in such a way as to disrupt the burners. This is caused quenching of a flame. A quenched flame, creates CO. https://www.sciencedirect.com/science/article/pii/B9781483197531500099
For a more detailed explanation of why not to use gas ovens to heat, click here. https://allairsystemsnj.com/using-an-oven-to-heat-a-house-heres-why-its-a-bad-idea/
What is the takeaway to avoiding carbon monoxide disasters? A modern household is not intended to be heated by anything other than a furnace or electrical heat device. Improvising can be dangerous. Always remember that using a fire, be that in your oven, your car, or in a generator, comes with the risk of exhaust, which must be presumed to include CO. If that exhaust isn’t removed from the dwelling, poisoning may occur.
CO Alarms Save Lives
A properly maintained carbon monoxide alarm will warn of most poisonings and should certainly alarm before anyone dies. Many of these storm related deaths and poisonings would be avoided if all dwellings had carbon monoxide alarms installed. Such alarms should always be where anyone sleeps, regardless of whether there is a fuel burning appliance in that space. As in the commercial boiler with an iced up exhaust flue, CO may migrate to occupied spaces, distant from the actual fire.
[1] We have personally seen levels as high as 90,000 ppm in generator exhaust but never more than 9,000 from a furnace or other HVAC device.
[2] https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6303a6.htm?s_cid=mm6303a6_e and https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5650a1.htm
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