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SAFETY 101: CARBON MONOXIDE



What is carbon monoxide?
Carbon monoxide (CO) is a poisonous, colorless, odorless, and tasteless gas. Although it has no detectable odor, CO is often mixed with other gases that do have an odor. So, you can inhale carbon monoxide right along with gases that you can smell and not even know that CO is present.

CO is a common industrial hazard resulting from the incomplete burning of natural gas and any other material containing carbon such as gasoline, kerosene, oil, propane, coal, or wood. Forges, blast furnaces and coke ovens produce CO, but one of the most common sources of exposure in the workplace is the internal combustion engine.

How does CO harm you?
Carbon monoxide is harmful when breathed because it displaces oxygen in the blood and deprives the heart, brain, and other vital organs of oxygen. Large amounts of CO can overcome you in minutes without warning - causing you to lose consciousness and suffocate.

Besides tightness across the chest, initial symptoms of CO poisoning may include headache, fatigue, dizziness, drowsiness, or nausea. Sudden chest pain may occur in people with angina. During prolonged or high exposures, symptoms may worsen and include vomiting, confusion, and collapse in addition to loss of consciousness and muscle weakness. Symptoms vary widely from person to person. CO poisoning may occur sooner in those most susceptible: young children, elderly people, people with lung or heart disease, people at high altitudes, or those who already have elevated CO blood levels, such as smokers. Also, CO poisoning poses a special risk to fetuses.

CO poisoning can be reversed if caught in time. But even if you recover, acute poisoning may result in permanent damage to the parts of your body that require a lot of oxygen such as the heart and brain. Significant reproductive risk is also linked to CO.

Who is at risk?
You may be exposed to harmful levels of CO in boiler rooms, breweries, warehouses, petroleum
refineries, pulp and paper production, and steel production; around docks, blast furnaces, or coke ovens; or in one of the following occupations:
Welder
Garage mechanic
Firefighter
Carbon-black maker
Organic chemical synthesizer
Metal oxide reducer
Longshore worker
Diesel engine operator
Forklift operator
Marine terminal worker
Toll booth or tunnel attendant
Customs inspector
Police officer
Taxi driver

What can you do if you suspect someone has been poisoned?
When you suspect CO poisoning, promptly taking the following actions can save lives:
Move the victim immediately to fresh air in an open area.
Call 911 or another local emergency number for medical attention or assistance.
Administer 100-percent oxygen using a tight-fitting mask if the victim is breathing.
Administer cardiopulmonary resuscitation if the victim has stopped breathing.

Warning: You may be exposed to fatal levels of CO poisoning in a rescue attempt. Rescuers should be skilled at performing recovery operations and using recovery equipment. Employers should make sure that rescuers are not exposed to dangerous CO levels when performing rescue operations.

How can employers help prevent CO poisoning?
To reduce the chances of CO poisoning in your workplace, you should take the following actions:
Install an effective ventilation system that will remove CO from work areas.
Maintain equipment and appliances (e.g., water heaters, space heaters, cooking ranges) that can produce CO in good working order to promote their safe operation and to reduce CO formation.
Consider switching from gasoline-powered equipment to equipment powered by electricity, batteries, or compressed air if it can be used safely.
Prohibit the use of gasoline-powered engines or tools in poorly ventilated areas.
Provide personal CO monitors with audible alarms if potential exposure to CO exists.
Test air regularly in areas where CO may be present, including confined spaces. See Title 29 of the Code of Federal Regulations (CFR) 1910.146.
Install CO monitors with audible alarms.
Use a full-face piece pressure-demand self-contained breathing apparatus (SCBA) certified by the National Institute for Occupational Safety and Health (NIOSH), or a combination full-face-piece pressure demand supplied-air respirator with auxiliary self-contained air supply in areas with high CO concentrations, i.e., those immediately dangerous to life and health atmospheres. (See 29 CFR 1910.134.)
Use respirators with appropriate canisters for short periods under certain circumstances where CO levels are not exceedingly high.
Educate workers about the sources and conditions that may result in CO poisoning as well as the symptoms and control of CO exposure.

In addition, if your employees are working in confined spaces where the presence of CO is suspected, you must ensure that workers test for oxygen sufficiency before entering.

What can employees do to help prevent CO poisoning?
Employees should do the following to reduce the chances of CO poisoning in the workplace:
Report any situation to your employer that might cause CO to accumulate.
Be alert to ventilation problems - especially in enclosed areas where gases of burning fuels may be released.
Report promptly complaints of dizziness, drowsiness, or nausea.
Avoid overexertion if you suspect CO poisoning and leave the contaminated area.
Tell your doctor that you may have been exposed to CO if you get sick.
Avoid the use of gas-powered engines, such as those in powered washers as well as heaters and forklifts, while working in enclosed spaces.

What are the federal OSHA standards for CO exposure?
The OSHA permissible exposure limit (PEL) is 50 parts per million (ppm). OSHA standards prohibit worker exposure to more than 50 parts of the gas per million parts of air averaged during an 8-hour time period.
The 8-hour PEL for CO in maritime operations is also 50 ppm. Maritime workers, however, must be removed from exposure if the CO concentration in the atmosphere exceeds 100 ppm. The peak CO level for employees engaged in Ro-Ro operations (roll-on roll-off operations during cargo loading and unloading) is 200 ppm.

NOTE: In 1989, MNOSHA adopted an 8-hour Time Weighted Average (TWA) Air Exposure Limit for carbon monoxide in General Industry of 35 ppm and a 5-minute Ceiling limit of 200 ppm. The 8-hour TWA exposure limit for carbon monoxide in the Construction Industry in Minnesota is 50 ppm.

For help tailored to your specific needs, contact the Minnesota Safety Council at 651-291-9150/800-444-9150.

Acknowledgments:
U.S. Dept. of Labor, OSHA