When we think of natural gas being dangerous
(or propane which is derived from natural gas) usually the first thought
that comes to mind is an explosion. If you smell gas you might be
worried about the house blowing up. If you donít smell gas you probably
think thereís nothing to worry about. This is a bad assumption. Often
there are toxic chemicals in homes with natural gas at levels below what
you can smell. Pure natural gas does not have an odor. The gas company
puts a smelly chemical called mercaptin in it so you can smell large gas
leaks. Mercaptin itself is toxic. They only put enough in the gas supply
so you can smell the big gas leaks.
The main component of natural gas is 98% methane. According to material
safety data sheets, breathing methane is not harmful. The only
officially documented hazard from breathing methane is asphyxiation. You
suffocate. This really doesnít seem common sense. Does this mean
breathing natural gas is harmless as long as I donít suffocate?
According to the gas company it is. But thatís not taking into
consideration the remaining 2% of the ingredients. Gas as delivered to
your home or office contains many toxic ingredients and pollutants.
Gas comes from the ground. Like
un-filtered tap water, it contaminates from the ground and from the gas
supply lines. These include:
- Heavy metals
- VOCs, benzene, toluene
There is a network of gas supply lines
distributed across the country and shared by different gas companies.
You literally donít know where the gas you use comes from and what might
be in it.
Toxic chemicals are either intentionally added or picked up in the gas
supply lines. This includes PCBs, dioxins, benzene, toluene, tars, oils,
waxes and other "plug-flow" type chemicals. Many of these are known or
probable carcinogens. These are sporadic and appear in the flame as
Some natural gas deposits have been found to contain high concentrations
of heavy metals, including lead, copper, mercury, silver, and arsenic.
They accumulate on the burners of gas stoves as black deposits. Check
the area around the pilot light. If there is a white powder it is likely
arsenic oxide. Some natural gas deposits contain radon. Radon is known
to cause lung cancer and can be transported into buildings that use
Chemicals Produced when Gas is Burned
Even if gas was filtered before
being delivered to your home, burning gas would still expose you to
toxic chemicals. Like an automobile engine, no gas appliance burns with
100% efficiency. If there was 100% combustion efficiency, the
by-products would simply be water and carbon dioxide, basically what you
exhale when you breathe. But this is not the case. There are many toxic
combustion pollutants. Who likes to breathe exhaust from the tail pipe
of a car? The most are:
- Carbon monoxide
- Volatile Organic Compounds
Carbon monoxide is an odorless, colorless
gas that binds to hemoglobin in the blood stream with about 200 times
better than oxygen, reducing the amount of oxygen transported to tissue.
Formaldehyde is a known carcinogen. There is a long list of other
chemicals produced when gas is burned, most of which have difficult to
pronounce names and are carcinogens. Water vapor is produced during
combustion. Water vapor carries toxins deep into the lungs when you
You donít smell chemicals but they are present in your home when gas is
burned. On gas appliances where the pilot light is constantly lit they
are being spewed out twenty-four hours a day. Higher levels of carbon
monoxide may occur indoors when a gas appliance back drafts. Back
drafting occurs when the exhaust does not go up the flue because there
is not enough make-up air indoors. The potential for this is higher in
homes that are air-tight or weatherized for energy efficiency.
Natural gas has been found to be one
of the most important sources of indoor air pollution. Natural gas can
induce or worsen allergy, asthma and chemical sensitivity. Breathing
even small amounts of gas compromises the immune system and increases
the risk for asthma attacks, waking with shortness of breath and
tingling sensations in the extremities. Clinical studies show that the
use of natural gas in the homes, schools, work places or even in the
neighborhoods can exacerbate illness and inhibit recovery.
Carbon Monoxide Poisoning
Most people have heard about
carbon monoxide poisoning. Carbon monoxide is one of the primary
components when gas is burned. Lower concentrations of carbon monoxide
may cause headaches, dizziness, nausea and fatigue in healthy people and
chest pain in people with heart disease. At high concentrations it can
cause unconscious and result in death. According to the Center for
Disease Control (CDC), carbon monoxide sends over 10,000 to the hospital
and kills over 1,500 each year.