CARBON MONOXIDE HAZARDS AND YOUR HEALTH.

Carbon monoxide (CO) is a colorless, odorless, and tasteless gas that is slightly less dense than air. It is toxic to humans when encountered in concentrations above about 35 ppm, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal biological functions. In the atmosphere, it is spatially variable and short lived, having a role in the formation of ground-level ozone.

Carbon Monoxide (CO) Poisoning in Your Home

Carbon monoxide (CO) is an odorless, colorless gas often formed in the process of incomplete combustion of organic substances, including fuels. It is dangerous because it interferes with normal oxygen uptake for humans and other living organisms needing oxygen to live.

Why should I be concerned about Carbon Monoxide (CO)?

CO is a gas that can build up to dangerous concentrations indoors when fuel- burning devices are not properly vented, operated, or maintained. Because it has no odor, color or taste, CO cannot be detected by our senses. It is estimated . Between 8,000 to 15,000 people each year are examined or treated in hospitals for non-fire related CO poisoning. Breathed over long periods of time, low concentrations of CO may also contribute to other illness. Fortunately, simple measures can be taken to prevent CO problems. One such action is the installation of a CO alarm to detect potentially deadly conditions.

What are the sources of CO?

In general, CO is produced when any material burns. More is produced when there isn’t enough oxygen for efficient burning. Common sources of CO in homes include fuel-burning devices such as: furnaces, gas or kerosene space heaters, boilers, gas cooking stoves, water heaters, clothes dryers, fireplaces, charcoal grills, wood stoves, lawn mowers, power generators, camp stoves, motor vehicles and some power tools with internal combustion engines. Smoking is another common source of CO that can negatively impact indoor air quality.

What concentrations of CO are typical in the home?

Ideally, CO concentrations indoors are expected to be the same as CO concentrations outdoors. In the Minneapolis/St. Paul area, CO concentration in the outdoor air ranges from 0.03-2.5 parts per million parts (ppm). This is averaged over an 8-hour period. These averages are below the federal standard of 9 ppm for CO in outdoor air. In general, concentrations are lower in rural areas and higher in urban areas. Finding CO concentrations higher indoors than outdoors indicates an indoor source of CO, or a source very close to your home.

How can I protect myself and my family from CO poisoning?

Simple measures can be taken to prevent CO problems. Make sure that all your fuel burning appliances and heating devices are properly vented and maintained. Know the symptoms of CO poisoning. Finally, to detect potentially deadly conditions, install and maintain CO alarms in your home in accordance with Minnesota's CO alarm law.

1. Properly vent and maintain fuel-burning appliances.

Homes with fuel-burning appliances such as gas furnaces, water heaters, ovens, and fireplaces or homes with attached garage are more likely to have CO problems than those homes not using these appliances. You should have your fuel-burning appliances checked by a qualified heating contractor every year to look for possible problems.

The following signs may indicate a CO problem:

• Streaks of soot around fuel-burning appliances;
• Absence of an upward draft in your chimney;
• Excess moisture found on windows, walls, or other cold surfaces;
• Excessive rusting on flue pipes, other pipe connections, or appliance jacks;
• Orange or yellow flames (should be blue) in your combustion appliances;
• Smoky smells-don't assume your fire alarm works;
• Fallen soot in the fireplace;
• Small amount of water leaking from the base of the chimney vent, or flue pipe;
• Damaged or discolored bricks at the top of your chimney; and
• Rust on the portion of the vent pipe visible from the outside.

Never use a barbeque grill or portable gas generator indoors. Never heat your home using an oven designed for cooking.

2. Know the symptoms of CO poisoning.

The health effects of breathing in CO depend on the concentration of CO in the air, the duration of exposure, and the health status of the exposed person. For most people, the first signs of exposure to low concentrations of CO include mild headache and breathlessness with moderate exercise. People with heart disease are more likely to be affected by CO, even at low concentrations. Continued exposure can lead to flu-like symptoms including more severe headaches, dizziness, tiredness, and nausea that may progress to confusion, irritability, and impaired judgment, memory and coordination. CO is called the "silent killer" because if the early signs are ignored, a person may lose consciousness and be unable to escape to safety. Under certain conditions, lethal concentrations of CO have occurred within 10 minutes in the confines of a closed garage with a car engine running inside or when a portable generator is used in or near a house.

How can I tell the difference between CO poisoning and the flu?

It could be CO poisoning if:

• You feel better when you are away from your home;
• Several people in the home gets sick at the same time (the flu is usually passed from person to person);
• The family members who are most affected spend the most time in the home;
• Symptoms occur or get worse shortly after turning on a fuel-burning device (furnace, oven, fireplace) or running a vehicle in attached garage;
• Indoor pets also appear ill (pets may experience symptoms first);
• You don’t have a fever or generalized aching and swollen lymph nodes typical with a cold or virus or flu; or
• Symptoms appear at the same time as signs of inappropriate ventilation, maintenance, or operation of fuel-burning devices.

3. Install and maintain CO alarms in your home.

Minnesota State Law requires that homes have at least one operational CO alarm within 10 feet of every room legally used for sleeping (see Minnesota Statute, 299F.50). All CO alarms should be certified by a nationally recognized testing laboratory to conform to the latest Underwriters Laboratory (UL) Standards. Follow the manufacturer's instructions for placement of your CO alarm and also note the suggested replacement date. For additional information on CO alarms, contact:

• State Fire Marshal

Can I experience CO poisoning from tobacco smoke?

Tobacco smoke, also known as "environmental tobacco smoke," contains CO in addition to many other hazardous chemicals and particles. Concentrations of CO in second hand smoke are too low to cause immediate poisoning, but breathing second-hand smoke for a long time can adversely affect the health of those exposed to it.

Are some people at greater risk of CO poisoning than others?

Yes, some people are at greater risk of CO poisoning. People at greater risk include individuals with:

• respiratory conditions (such as asthma and emphysema);
• cardiovascular disease;
• anemia (such as sickle cell anemia); and
• individuals engaging in strenuous physical activity;
• the elderly, children and fetuses.

Remember, anyone can become sick and die from CO poisoning when exposed to very high CO levels.

Can CO be a problem during the summer?

Yes. Although CO problems are more common during the heating season, vehicles including boats and some other fuel burning devices such as non-electric heaters for camping and fishing are used year-round and can be sources of CO during recreational activities.

CO poisoning has resulted from the use of fuel burning devices during power outages. Portable generators are capable of producing carbon monoxide levels that are several hundred times the levels emitted by a modern car exhaust and can kill people in a very short time.

As recommended by CDC, portable generators should be placed at a minimum of 25 feet away from and down wind of a house. Be sure that there are no vents or openings, including window air conditioners, near the generator that would allow exhaust to enter into your home.

Where else could I experience CO poisoning?

Anytime you are near a fuel-burning device, there is a risk of CO exposure. Because vehicles are a common source of CO problems, MDH recommends that you not run or idle your vehicle in an attached garage. Instead, back your vehicle out right away. MDH also recommends that you check that your vehicle’s exhaust pipe is not blocked, for example, by snow during the winter.

Fatalities due to CO inhalation have also occurred from boat motors. Be sure to follow manufacturer’s guidelines and warn children about potential dangers near parts of the boat where exhaust concentrations could be high.

Dangerous concentrations of CO may also be produced by burning fossil-fuel appliances, such gas stoves or charcoal grills in any enclosed space including campers, tents, and ice fishing houses.

Finally, inhalation of paint removers containing methylene chloride can also result in carbon monoxide poisoning. Be sure to follow directions and use products containing methylene chloride and other chemicals in well-ventilated areas.

Carbon monoxide consists of one carbon atom and one oxygen atom, connected by a triple bond that consists of twocovalent bonds as well as one dative covalent bond. It is the simplest oxocarbon, and isoelectronic with the cyanide ion and molecular nitrogen. In coordination complexes the carbon monoxide ligand is called carbonyl.

Carbon monoxide is produced from the partial oxidation of carbon-containing compounds; it forms when there is not enough oxygen to produce carbon dioxide (CO₂), such as when operating a stove or an internal combustion engine in an enclosed space. In the presence of oxygen, including atmospheric concentrations, carbon monoxide burns with a blue flame, producing carbon dioxide.^[ Coal gas, which was widely used before the 1960s for domestic lighting, cooking, and heating, had carbon monoxide as a significant fuel constituent. Some processes in modern technology, such as iron smelting, still produce carbon monoxide as a byproduct.

Worldwide, the largest source of carbon monoxide is natural in origin, due to photochemical reactions in the troposphere that generate about 5×10¹² kilograms per year.^[5] Other natural sources of CO include volcanoes, forest fires, and other forms of combustion.

In biology, carbon monoxide is naturally produced by the action of heme oxygenase 1 and 2 on the heme from hemoglobin breakdown. This process produces a certain amount of carboxyhemoglobin in normal persons, even if they do not breathe any carbon monoxide. Following the first report that carbon monoxide is a normal neurotransmitter in 1993,^[as well as one of three gases that naturally modulate inflammatory responses in the body (the other two being nitric oxide and hydrogen sulfide), carbon monoxide has received a great deal of clinical attention as a biological regulator. In many tissues, all three gases are known to act as anti-inflammatories, vasodilators, and promoters ofneovascular growth. Clinical trials of small amounts of carbon monoxide as a drug are ongoing.

Deadly fumes from vehicle exhaust include carbon monoxide (CO), a colorless, odorless, tasteless, and non-irritating byproduct of incomplete combustion. Greiner has consulted on and investigated several cases of poisoning from car fumes, some resulting in death.

Carbon monoxide reduces the oxygen supply to the brain, causing carbon monoxide intoxication. At high concentrations, such as produced in the exhaust of a cold engine, carbon monoxide intoxication occurs in only a few minutes, leaving those poisoned incapable of realizing they are poisoned, and unable to protect themselves. Carbon monoxide poisoning can happen to anyone, although children, the elderly and those with health concerns are especially susceptible.

To prevent carbon monoxide poisoning from vehicles:

• NEVER run engines in a garage, even if the garage door is open.
• Make certain all vehicles are tuned up and running clean.
• Check and repair exhaust system leaks.

When starting a car and leaving from the garage:

• Make certain everyone is in the car and ready to leave.
• Open the overhead garage door before starting the car.
• Start the car and immediately back out.
• Shut the garage door.
• Immediately drive away. Consult the owner's manual for recommendations when driving with a cold engine.