Using compressed air for cleaning grain dust is acceptable but does increase the potential for a dust explosion or flash fire. For this reason, the Occupational Safety and Health Administration’s (OSHA) Grain Handling Standard 1910.272 requires that the use of compressed air to blow dust from ledges, walls, and other areas only be permitted when:

  • All machinery that presents an ignition source is shut down.
  • All other known potential ignition sources in the area are removed or controlled.

Exposure to compressed air can also cause severe injury. Compressed air can enter the bloodstream through a break in the skin or body opening causing an embolism. An embolism (air bubble) can obstruct or block a blood vessel or artery, resulting in coma, paralysis, and death depending on its size, duration, and location. The pressure necessary to remove particles from equipment and surfaces is also strong enough to blow solid particles into the eyes, ears, or skin.

OSHA requires that compressed air not be used for cleaning purposes except where reduced to less than 30 psi and with effective chip guarding and personal protective equipment, such as protective goggles and respiratory protection. The phrase, "reduced to less than 30 psi" means that the nozzle pressure or opening of a gun, pipe, or cleaning lance used for cleaning purposes will remain at a pressure level below 30 psi if the tool is dead ended. This is achieved by using equipment with relief ports that discharge air to reduce the air pressure at the nozzle to less than 30 psi. The term “dead ended” refers to blocking of the tip of the air gun, pipe, or lance.

Effective chip guarding means any method or equipment that prevents a chip or particle from being blown into the eyes or unbroken skin of the operator or other workers. The use of protective cone air nozzles is acceptable protection for the operator. In addition, worker should never use compressed air to clean themselves or their clothing.

Remember, safety doesn’t have to be difficult, simple steps, such as shutting down machinery that present an ignition source prior to using compressed air to clean combustible dust, can prevent injuries and save lives.

Source: Joe Mlynek is president of Progressive Safety Services LLC, Gates Mills, OH: joe.mlynek@progressivesafety.us, and content creation expert for Safety Made Simple, Inc., Olathe, KS; joe@safetymadesimple.com