Using compressed air for cleaning isn’t difficult. However, many employers and their employees don’t know how to do so safely. That’s because Compressed air used for cleaning [1910.242(b)] remains one of Oregon OSHA’s most frequently violated general industry rules in manufacturing
That sobering fact calls for a refresher on the rule. Its three key points are:
- The compressed air must be reduced to less than 30 psi at the discharge end of the nozzle.
- “Effective chip guarding” must prevent chips or other debris from being blown back on the worker.
- Personal protective equipment appropriate for the cleaning task is required.
The rule is there for a reason: Cleaning carelessly with compressed air can cause serious injuries, including eye damage, hearing loss, air embolisms, and severe infections.
Compressed air must be reduced to less than 30 psi at the discharge end of the nozzle.
Let’s assume you’re blowing filings off a bench grinder with an air gun, and the pressure at the nozzle is 90 psi. Some employers think that the only way to reduce the pressure to less than 30 psi is to lower the compressed air line pressure below 30 psi before it reaches the gun. That’s an acceptable practice, but it’s not effective for most cleaning tasks.
Today, most safety air gun nozzles have side ports that allow you to clean at higher pressures, such as 90 psi, but do not exceed 30 psi if the nozzle’s discharge end is blocked (also called “dead ended”). The side ports prevent the full velocity and force of the compressed air from injuring you or another worker.
If the nozzle tip becomes blocked, all of the main air flow exits through the side ports and the nozzle pressure does not exceed 30 psi. (Graphic by Guardair Corporation)
Never clean yourself or your clothes (while you’re wearing them) with compressed air and never point an air nozzle at any part of your body or at anyone else – even when you’re sure the pressure does not exceed 30 psi.
“Effective chip guarding” must prevent chips or other debris from being blown back on the worker.
Nozzle designed with a built-in protective air cone. (Graphic by Guardair Corporation)
The pressure necessary to remove the particles from machines and other surfaces is strong enough to blow them into your eyes, ears, or abrasions in your skin. Effective chip guarding prevents this from happening.
The chip guard – such as a screen or other barrier – can be part of the air nozzle or a separate item. Some air guns are designed with nozzles that divert a small portion of air to form a protective air cone around the nozzle, reducing or eliminating the chance that particles could fly back toward you.
Personal protective equipment appropriate for the cleaning task is required.
Safety goggles, gloves, and hearing protection are appropriate for any compressed-air cleaning task. Safety goggles prevent any stray particles from flying back into the user’s eyes. A good pair of gloves makes any cleaning task easier, and hearing protection is important because cleaning with compressed air can exceed Oregon OSHA’s noise limits. Low-noise safety air guns can also be effective in lowering noise levels.
Depending on the task, other PPE may also be necessary. It’s a good idea to do a PPE hazard assessment to determine what other PPE you might need.
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