Carbon Monoxide Alert

There have been two fatalities in Tennessee in recent history where compressors overheated producing extremely high levels of carbon monoxide. We strongly recommend that non-oil lubricated air compressors be used to supply breathing air to employees who use supplied-air respirators. If an oil-lubricated compressor is used, BE SURE that:

• The compressor has a high-temperature alarm or carbon monoxide alarm, or both
  
  
• If only a high temperature alarm is used, the air from the compressor is frequently tested for carbon monoxide to insure that it meets the specifications for Grade D air. (We are continuing to review information on this subject to determine how often the carbon monoxide levels must be tested in breathing air to meet the requirement for "frequent" testing.)

In addition, when using any type of compressor to supply breathing air (oil lubricated or non-oil lubricated), BE SURE that:

• The air intake is located to avoid entry of contaminated air into the compressor
  
  
• The moisture content is minimized so that the dew point at 1 atmosphere pressure is 10 degrees below the ambient temperature
  
  
• In-line sorbent beds and filters are installed to further assure air quality. Be aware that "air filters" on breathing air compressors do not remove or detect carbon monoxide. Filters must be maintained and replaced or refurbished periodically following the manufacturer's instructions.
  
  
• A tag is located at the compressor containing the most recent filter change date and the signature of the person authorized to perform the change
  
  
• Couplings are incompatible with outlets for other non-breathable air (such as nitrogen)
  
  
• No asphyxiating substances are introduced into breathing air lines
  
  
• The air supplied by the compressor meets the criteria for Type 1-Grade D breathing air described in ANSI/Compressed Gas Association Commodity Specifications for Air, G-7.1-1989 which are as follows:
  
  
  • Oxygen content 19.5-23.5%
  • Carbon monoxide 10 ppm or less
  • Hydrocarbon content 5 mg/m3 or less
  • Carbon dioxide 1,000 ppm or less
  • Lack of noticeable odor

• For IDLH atmospheres, the wearer also has an auxiliary self-contained bottle of air to be used for escape if the air compressor fails

Adhering to these rules will go a long way toward ensuring that the job will get done with no tragic consequences to your employees.

---

TOSHA
220 French Landing Drive
Nashville, Tennessee 37243
Ph: (615) 741-2793
Fax: (615) 253-1623
Toll Free: 1-800-249-8510

Send comments to Division of Occupational Safety and Health