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Five Minute Safety Talk No.13

"Compressed Air"


Compressed air is dangerous and must be used in a safe manner. So before grabbing an air hose and going into action, there are a number of safety guidelines which should be followed.

First of all, make certain that you have an airline, not gas or water. Fittings and valves look different, but sometimes hose lines cross and you could be fooled. Take time to make sure, each time you use compressed air.

Next, check to be sure the air hose is in good condition. Air hose is designed to withstand pressure, but it becomes weakened at the places where it is bent, where it is attached to the shut off valve and to the nozzle and wherever it has been kinked. Such weak points may swell like a balloon and burst, throwing pieces of hose in every direction. This may also cause the hose to thrash about dangerously. These precautions should be followed:

Keep air hose off the floor where it is a trip hazard and subject to damage by trucks, doors, and dropped tools.

Prevent sharp objects—even hose fittings that have been burred—from rubbing against the hose.

Always coil the hose—without kinks—and hang it over a broad support, not over a hook, nail, or angle iron, when not in use.

Where you have choice of pressure, use the lowest pressure that will do the job. There are many good reasons for this and here are a few:

Air pressure in excess of 30 Ibs. can drive chips, as well as scale from inside the piping, into your face and eyes with the force of shrapnel. Such air driven missiles still do damage when they bounce off a surface, spinning much like a high speed cutting head.

Air pressure against the skin may penetrate deeply to cause internal hemorrhage and intense pain.

Air that enters a body opening can burst internal organs and cause slow, agonizing death.

Air in excess of 30 lbs. can blow an eye from its socket, and/or rupture an eardrum.

Certainly no one would intentionally cause such injuries. Yet every so often someone does, either accidentally or in ignorance, thinking it's a joke.
The nozzle of an air hose is a deadly weapon. Don't point it at anyone, not even yourself. Use safer, better ways of cleaning dust from your clothes—by vacuum cleaning or brushing. Dust blown from anything merely rises a little and then settles again to become a nuisance. Some of the dust blown into the air ends up in our lungs, and that's not where we want it.

MlOSHA's General Provisions Standard states "air pressure at the discharge end of a portable air blow gun or portable air hose should be less than 30 lbs. per square inch gauge when dead-ended."

In a few cases, standard safe procedures are set up for trained employees using equipment with known safety factors and observing approved safe practices. These include the following instances:

Removing dust or particles from jigs, fixtures, deep holes in parts. Use low pressure, 30 Ibs. or less, and the right nozzle. Wear cup-type goggles and set up shields to protect passers-by, and others in the area.

For transferring liquids from properly rated pressure vessels, check air pressure, attach hose connection tightly, remain at control valve to shut off in an emergency, and make sure bleed-off valve and pressure relief valve work. Never use compressed air to transfer flammable liquids.

Compressed air must be treated with respect. It's a valuable tool but it must be used intelligently and in a safe manner.

Note: A copy of the General Industry Safety Standard on Part 1, General Provisions may be obtained by calling the Standards Division at 517-284-7750 or online.

To request consultation education and training services, call: 517-284-7720.

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Michigan Department of Licensing and Regulatory Affairs
Michigan Occupational Safety and Health Administration
Consultation Education & Training Division
530 W. Allegan Street, Box 30643
Lansing, MI 48909-8143

  MIOSHA-CET-13 (Rev. 1/04)