Vent Free Gas Fireplaces & Kerosene Space Heaters Linked To Cancer & Birth Defects

Apr 19, 2007 (Updated Nov 8, 2007)

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The Bottom Line Venting fossil fuel combustion products, up a chimney or through the wall to the outdoors, is simple common sense. Why would anyone risk their health or life doing otherwise?

In this review I am going to attempt to make a complicated problem, less complicated, I want to simplify things a bit. However it comes out, it is the message that is important and it must be loud and clear. Please read it all and think about products in your own home that use these fuels and appliances.

One of the reasons why this issue is so complicated is that fossil fuels have numerous sources of supply that are not all equal in content. There are life threatening contaminants found in the natural gas fields of the South-West U.S.A., that are not found in any other gas fields and then there are different contaminants found in the gas fields of North-Eastern Canada that are not common to the U.S.A. The same problems hold true for the production of diesel, gasoline and kerosene. Each of these grades of petroleum products can contain varying levels of contaminants, such as lead, arsenic, and mercury depending upon the place they were extracted from. We may not drink them, but we are definitely exposed to inhaling them.

Over the course of the past several years I have outlined numerous ways in which vent-free fuel burning appliances can harm or even kill people. I have also told readers that the State of California, Canada, a country that knows about cold, Wisconsin and New York City has banned vent free gas fireplaces since around January of 1989. In order to appreciate why a large state like California would take such drastic measures, you need to know that in the late 1980's the Environmental Protection Agency (EPA) determined there are certain chemicals within fossil fuels (oil and gas) and their combustion by-products that should be classified as carcinogenic and/or dangerous to human health.

Canada had their Interprovincial Gas Advisory Council (IGAC) look at it a long time ago and it took them very little time to decide it was a bad idea. BANNED

Back in 1989 California Health & Safety choose to take the unprecedented step of passing into law, what is now known as Proposition 65, which requires the Governor of California to update annually a list of chemicals known to cause cancer. It further demands that those who sell products that may cause cancer, birth defects or other reproductive harm warn consumers accordingly.

To this day, as I have already said, vent free products are banned in certain countries around the world, like Canada and in some states like Wisconsin, Mass, New York City and a number of municipalities across the United States, however, no gas appliance may be sold in California, without the following warning prominently displayed within the instruction manuals:

Proposition 65 Warning: Fuels used in gas, woodburning or oil fired appliances and the products of combustion of such fuels, contain chemicals known to the State of California to cause cancer, birth defects and other reproductive harm. California Health and Safety Code Sec. 25249.6

Needless to say, most manufacturers "hate" this law, as it forces them to say something to the buying public that is not exactly flattering or highlighting a positive aspect of their products and it often raises questions from their consumers that are difficult for sales representatives to answer,... honestly.

California Health and Safety apply these same rules to their labor codes to establish safe and unsafe exposure of workers to various chemicals.

Remember, Canada has said no, no, no, despite increased pressure from the Vent-free gas products alliance suported by their Gas appliance manufacturers association.

Something else that I feel I need to stress is that some people would have you believe that kerosene and gas appliances burn 100% of the fuel used. It is actually impossible to burn 100% of any fuel. Even natural gas and propane which come the closest, will rarely achieve 99% combustion efficiency. By-products of combustion include carbon dioxide, (CO2) nitrogen oxides (NOX) water vapor (H20) and heat energy, at least, that is what most sales people will say. Especially if they are selling you a vent free fireplace or a kerosene heater.

NO SCIENTIST IN THE WORLD WOULD EVER CLAIM THAT GAS, OIL, or KEROSENE heaters are capable of burning 100% of the fuel being injected and burned. Raw carbon products are going into the home of anyone with vent-free products.

In addition to the common by-products of combustion there will be particulate matter that becomes air-borne and in the case of kerosene heaters, you may also have acid aerosols. Particles can be tiny microns of unburnt fuel, to larger particles of solid carbon (soot). We can safely predict that the combustion rate of the fuel will be far less than 99%. When it first lights up and when it shuts down, a portion of unburnt fuel is ejected into the room and until the appliance has reached higher operating temperatures combustion efficiency is never perfect.

So in addition to the above mentioned normally anticipated by-products of combustion, we must add potential products of incomplete combustion, such as carbon monoxide, benzo(a)pyrene (a highly carcinogenic hydrocarbon), sulfur dioxide and something that varies from state to state and country to country, "other pollutants". Toluene is present in some natural gas and is known to cause reproductive harm.

Carbon Monoxide
I think I have pretty well covered the dangers of carbon monoxide (CO), in my many previous reviews. I doubt many people haven't read all about, "the silent killer", as the media is fond of calling it. However, it should always be in the forefront of your mind, as a major potential source of danger to your health and even your life.

Nitrogen Oxides (NOX)
Scientists have been learning more and more about the dangers of prolonged and repeated exposure to NOX. It was once thought to be harmless, since almost 80% of the air we breathe is composed of nitrogen and when you combine nitrogen rich air (79% Nitrogen and 21% Oxygen) with the combustion process a primary accepted by-product is nitrogen dioxide and trioxide (NO2 NO3). However, science is catching up with industry and have found that being an oxide, when it comes in contact with moisture, it is mildly acidic (nitric acid). Unfortunately, the linings of our mucus membranes and lungs are terrific sources of moisture for the air-borne NOX gases.

Scientists have now drawn correlations between repeated high level exposure to NOX from unvented gas appliances, such as gas stoves, fireplaces, etc., to irritation of the eyes, nose and throat, as well as bouts of shortness of breath. Low level exposure has been linked to respiratory infections and some believe it may contribute to the development of emphysema. As usual those who are most susceptible to NOX exposure are children, the elderly and those with existing respiratory problems.


Next to CO, particles are perhaps one of the most dangerous by-products of the combustion process and one of the reasons I advocate only using vented fuel burning appliances. Particulate matter as I said, can be microscopic unburnt fuel, carbon (soot), other impurities that passed through the combustion process, such as dust, air fresheners, and household cleaners. In essence, one could have a cocktail of invisible pollutants mixed with those flue gases. Particles are easily attached to by other pollutants such as benzo(a)pyrene and radon which are inhaled deep into the lungs and are both known to cause lung cancer.

The EPA has determined that radon (a naturally occurring radioactive substance) is present in the soil and homes across most of North America. By some official estimates, 1 in 15 homes have some levels of radon and the World Health Organization has stated it is a global problem. Probably the number two cause of lung cancer in non-smokers.

I think I have failed in my mission to keep this simple and to the point. So I will close with just a few more reminders of what others are saying.

* The esteemed: U.S. Environmental Protection Agency, says, "whenever possible use vented fuel burning heaters." "If you must use an unvented appliance, open doors to that room and crack the window open for fresh air."

* The U.S. Consumer Product Safety Commission echo's those suggestions.

* The American Lung Association says only use "vented" appliances.

* Canada, California, Wisconsin, and New York City say,... don't even think about selling them here, by banning them altogether.

* The most largest, most respected manufacturer of hearth products, in the United States and possibly in the world, HON Industries, refuse to make vent free gas fireplaces/heaters and cite several safety concerns in support of their early decision to not take part in this lucrative segment of their industry. HON Industries are also known as Hearth and Home Technologies or Fireside Hearth and Home, with nationally distributed brand names like HeatNGlo, Heatilator, and Quadra-Fire.

It isn't often we can find such a large corporation who put ethics and the consumer's health and welfare ahead of their own bottom line. That, in my opinion, is corporate integrity and they deserve our business for it.

Their corporate offices are in Minnesota. Their website is, and I highly recommend their products. They have the largest selection of vented gas fireplaces on the market today in designs, styes and sizes to suit anyone's aesthetic tastes or heating requirements.

Who Is Telling The Truth In This Debate?

I almost always receive argumentative emails disputing these kinds of reviews (especially from manufacturing members of the Vent Free Gas Products Alliance) and I'm ready for them.

Who do you choose to believe on this issue? Do you believe someone who has no profit motive for steering you away from vent free fireplaces and kerosene heaters and towards vented products, or those who have printed up expensive, glossy brochures to promote their dubious wares to you?

What motives would the U.S. Environmental Protection Agency (EPA), the American Lung Association(ALA), the U.S Consumer Product Safety Commission(CPSC), The U.S. Center For Disease Control (CDC), the governments of California, Canada, New York City and Wisconsin have, other than your health and well being?

Do not take a chance with the health and welfare of your family, just to save a couple of dollars. Use common sense, we do not normally like to light fires in our tents when we are camping. Why not?

Be safe, buy vented fuel burning appliances, use the overhead range hood when cooking with a gas stove, never use a gas stove/range to heat your home, vent products of combustion from your home, always ensure your home is well ventilated in the winter and have your chimney cleaned or checked for blockages.

The Gasman

P.S. Wood-burning can be almost as dangerous if you throw in a few pieces of pressure treated wood, color comics, or glossy newsprint. These are just a few of the things that can put out chemically altered products of combustion that are carcinogenic and or destructive to your catalytic combustor. Creosote, (the black tarish film that builds up inside chimney's from wood fireplaces and stoves, is more than a fire hazard, it also contains the carcinogen benzo(a)pyrene. So burn cured/dried wood, have the wood chimney cleaned annually by professionals and be safe.

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