The combination of any gasoline-powered equipment, (such as compressors, generators, welding equipment or forklifts) and any confined space in a construction site has the added danger of carbon monoxide poisoning – a potentially deadly hazard. As the CDC reports, “Often there is little time before [workers] experience symptoms that inhibit their ability to seek safety.”
Carbon monoxide (CO) is a colorless, odorless, toxic gas which interferes with the oxygen-carrying capacity of blood. CO can overcome a worker without warning and is covered specifically by OSHA standard 1917.24:
Exposure limits. The carbon monoxide content of the atmosphere in a room, building, vehicle, railcar or any enclosed space shall be maintained at not more than 50 parts per million (ppm) (0.005%) as an eight hour average area level and employees shall be removed from the enclosed space if the carbon monoxide concentration exceeds a ceiling of 100 ppm (0.01%).
Testing. Tests to determine carbon monoxide concentration shall be made when necessary to ensure that employee exposure does not exceed the limits specified in paragraph (a) of this section.
Instrumentation. Tests for carbon monoxide concentration shall be made by designated persons using gas detector tube units certified by NIOSH under 30 CFR Part 11 or other measuring instruments whose accuracy is as great or greater.
There are several important safety precautions that construction sites can employ to prevent CO hazards: from engine maintenance and building ventilation to alarms and safety training. Safety experts offer the following guidelines when using gasoline-powered equipment:
- Never use a generator indoors or in enclosed or partially enclosed spaces such as garages, crawl spaces, and basements. Opening windows and doors in an enclosed space may prevent CO buildup.
- Make sure the generator has 3-4 feet of clear space on all sides and above it to ensure adequate ventilation.
- Do not use a generator outdoors if placed near doors, windows or vents which could allow CO to enter and build up in occupied spaces.
- Always place the pump and power unit of high-pressure washers outdoors and away from air intakes so that engine exhaust is not drawn indoors where the work is being done. Run only the high-pressure wash line inside.
- Consider the use of tools powered by electricity or compressed air if they are available and can be used safely. For example, electric-powered tools present an electrocution hazard and require specific precautions for safety.
- If compressed air is used, place the gasoline-powered compressor outdoors away from air intakes so that engine exhaust is not drawn indoors where the work is being done.
- Use personal CO monitors where potential sources of CO exist. These monitors should be equipped with audible alarms to warn workers when CO concentrations are too high. More information on CO monitors is contained in the appendix.
- Anyone experiencing symptoms of CO poisoning should get to fresh air right away and seek immediate medical attention.
For more information, contact Diversified Safety Services.
