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Toolbox talk · 10 min · Tools & Equipment

Compressed Air and the 30 PSI Rule

Hazards: Air forced under the skin or into a wound, causing an embolism · Eye and face injury from blown chips, dust and swarf · Hearing damage from close-range air discharge · Hose whip if a coupling or hose fails under pressure

Why it matters

On May 20, 2019, a worker clearing a paper jam with a compressed air gun lost his grip and cut his hand. The cut let air into the tissue: an embolism, and a hospital stay (OSHA Summary Nr 116549.015). A year and a half later, an employee died after a co-worker used an air hose on him during horseplay (Nr 131899.015). This is why OSHA puts a number on it: under 30 psi, with chip guarding and PPE, or not at all.

Key points

  • Three conditions, not one. 1926.302(b)(4) and 1910.242(b): cleaning air reduced to less than 30 psi, and effective chip guarding, and PPE. Missing any one of the three is a violation.
  • The concrete-form exception lifts the pressure limit only. The sentence says the 30 psi requirement does not apply to concrete form and mill scale cleaning. It does not say the chip guarding and the PPE go away.
  • Air is never used on a person. Not on skin, not on clothing, not as a joke. Air that finds a cut goes into the bloodstream, and that has killed people.
  • Face shield and glasses, and check who is downwind. What you blow off a form lands on somebody — that is what chip guarding is for.
  • Lock it out before you clear it. Clearing a jam is servicing under 1910.147. Air gun in one hand and a live machine in front of you is the wrong shape of job.
  • Check the hose end and the coupling. The tool has to be positively secured to the hose (1926.302(b)(1)), and hoses over half an inch need a device that drops pressure if the hose blows (1926.302(b)(7)).

Do / Don't

Do

  • Use a regulated blow gun and know the pressure it delivers.
  • Reach for a brush, a broom or a vacuum first.
  • Point the nozzle at the work, away from your body and everyone else's.
  • Report a cut that happened near an air line, the same shift.

Don't

  • Blow dust off your own or anyone else's clothing, hair or skin.
  • Run an unregulated shop line straight into a blow gun.
  • Clear a jam, a chip pile or a form while the machine is energized.
  • Wrap, kink or crimp a hose to shut off the air.

Quick site check

  • Find every blow gun on site and check what pressure the line is regulated to.
  • Check that each air tool is positively secured to its hose, not just pushed on.
  • Pick the dirtiest surface on the job and decide together what cleans it instead of air.
Discussion — ask the crew
  1. Who used an air hose to blow themselves off this week? What were we cleaning off?
  2. Where are the blow guns on this site, and does anybody know what pressure they put out?
  3. Which machines here get cleared with air while they are still running?
  4. If we cannot use air to clean that surface, what do we use instead — and is it here?
  5. Who is standing downwind when somebody blows out a form or a panel?
Refs: 29 CFR 1926.302(b) — Pneumatic power tools, construction: (b)(4) the 30 psi cleaning limit with chip guarding and PPE and the concrete form and mill scale exception, (b)(1) positive means against disconnection, (b)(2) safety clips on percussion tools, (b)(5) manufacturer's safe pressure, (b)(7) safety device on hoses over half an inch, (b)(10) blast nozzle valve held open manually · 29 CFR 1910.242(b) — General industry: compressed air shall not be used for cleaning purposes except where reduced to less than 30 psi and then only with effective chip guarding and personal protective equipment (no exception in the text) · 29 CFR 1910.147 — Control of hazardous energy: servicing and maintenance where unexpected energization or release of stored energy could injure employees · OSHA Accident Search — Summary Nr 116549.015, event date 05/20/2019: employee using a compressed air gun to clear a machine jam lost his grip and cut his hand; the laceration caused an embolism and he was hospitalized · OSHA Accident Search — Summary Nr 131899.015, event date 12/15/2020: an employee died after a co-worker used an air hose on him during horseplaySign-in sheet included in the printed version

Frequently asked questions

1926.302(b)(4) in construction and 1910.242(b) in general industry use the same words: compressed air shall not be used for cleaning purposes except where reduced to less than 30 psi, and then only with effective chip guarding and personal protective equipment. Three conditions, all at once — under 30 psi, chip guarding, and PPE.

In construction, yes, and it is narrower than most people quote it. 1926.302(b)(4) adds that the 30 psi requirement does not apply for concrete form, mill scale and similar cleaning purposes. Read the words: what the sentence lifts is the 30 psi requirement. It says nothing about dropping the chip guarding or the PPE, and the general industry version at 1910.242(b) has no exception at all.

Below that pressure a blocked or dead-ended nozzle is far less likely to force air through skin or into a wound. The standard sets the limit; it does not certify that anything below it is harmless, which is why chip guarding and PPE are required in the same sentence.

Air pushed into the bloodstream through a cut or through the skin, where it can travel and block circulation. It is a medical emergency, and it is not theoretical: in the OSHA case above, a worker clearing a machine jam with an air gun lost his grip, cut his hand, and the laceration led to an embolism and a hospital stay.

No. Nothing about a person is a cleaning surface with effective chip guarding, and the pressure that feels harmless on a sleeve is the same pressure that opens a cut. Use a brush, a vacuum, or a shop vac with a HEPA filter where dust matters.

Clearing a jam is servicing. Under 1910.147, servicing and maintenance where unexpected energization or the release of stored energy could injure someone has to be done with the energy controlled — so the machine gets locked out, and then the jam gets cleared. Standing beside live rollers with an air gun is how hands and grips get lost.

1926.302(b)(1) requires the tool to be secured to the hose or whip by a positive means so it cannot come off, (b)(5) forbids exceeding the manufacturer's safe operating pressure for hoses and fittings, (b)(6) forbids using hoses to hoist or lower tools, and (b)(7) requires a safety device at the source of supply or branch line on any hose over half an inch inside diameter so the pressure drops if the hose fails.

A regulated tip helps, and many are built so the outlet cannot be fully dead-ended, but compliance is the whole sentence: pressure under 30 psi at the point of use, chip guarding that keeps the debris out of people, and PPE on the person holding it. Check what your gun is rated at instead of assuming.

Sources & references

Content checked against these sources — last reviewed August 28, 2026.

Results are estimates for planning purposes and do not replace a competent person's evaluation or an engineer's design. Follow the OSHA standards that apply to your work and your employer's written program.

By — Editorial team of SteelToeTools.com (published by LSEA SAS) Updated