Compressed air is used in industry for a variety of purposes and is considered the fourth utility after electricity, natural gas, and water. It’s used to drive portable hand tools, used in scuba diving tanks, used in some vehicle braking systems, and also for cleaning. Most machining and manufacturing operations have a compressed air system that allows for the quick connection of a flexible hose and air gun to clean dirt and debris from parts. OSHA sets a limit on the use of compressed air for cleaning in their Hand and Portable Powered Tools and Other Hand-held Equipment standard, 1910. 242, as follows:
Compressed air used for cleaning. Compressed air shall not be used for cleaning purposes except where reduced to less than 30 p.s.i. and then only with effective chip guarding and personal protective equipment.
While not explicitly stated, it is OSHA’s intent that employers in general industry should not allow employees to use compressed air to clean themselves or their clothing while being worn. However, OSHA does expressly state that, “compressed air shall not be used to clean employees” in their Marine Terminals standard, 1917.154, and recognizes this as a safe practice for all industries.
The greatest danger of using compressed air (even at pressures as low as 5-10 p.s.i.) is the risk of air entering the body and causing an air embolism in the bloodstream. This can be fatal. Other risks include damage to the eyes and respiratory system as well as hearing impairment if suitable protective equipment isn’t used.
It’s important to realize that most compressed air systems used for pneumatic tools and air guns operate at 80-120 p.s.i. In the case of air guns used for cleaning, the nozzle tip must be equipped with a relief device or port to reduce the pressure under 30 p.s.i. if the air system becomes obstructed or dead ended.
When purchasing air guns, look for those equipped with an engineered air nozzle meeting the OSHA less than 30 p.s.i. static pressure requirement along with a chip shield and noise output of less than 83 dBA.
Finally, always remember to wear the appropriate personal protective equipment when cleaning parts and equipment with compressed air.