What Is One of the Most Common Ways in Which Workers Get Hurt Around Machines?
One of the most common ways workers get hurt is reaching into a machine to clear a jam or clean it while parts are still moving. Contact with unguarded moving parts causes crushing, amputation, and caught-in injuries.
The answer
One of the most common ways workers get hurt around machines is reaching into a machine to clear a jam, clean, adjust, or service it while the parts are still moving. This is contact with unguarded or inadequately guarded moving parts, and it leads to some of the most severe workplace injuries: lacerations, crushing, fractures, and amputations.
The danger points on a machine are predictable. Workers are injured at the point of operation (where the machine cuts, presses, or shapes material), at pinch points and nip points (where two moving parts, or a moving and a fixed part, come together—like gears, rollers, or belts and pulleys), and on rotating parts (shafts, spindles, couplings) that can grab loose clothing, gloves, hair, or jewelry. The classic scenario is a jammed machine that a worker tries to clear quickly without shutting it down—the hand goes in, the part suddenly moves, and there is no guard to stop it.
Why this is the leading mechanism
Machine injuries cluster around this behavior for a simple reason: production pressure and habit push workers to fix small problems on the fly. Stopping a machine feels slower, so a jam gets cleared while it is running. But moving parts store and deliver enormous force, and human reaction time is far too slow once a hand is in the danger zone. That is why OSHA treats machine hazards not as "be careful" problems but as engineering-control problems: the machine itself must be built so the worker cannot reach the hazard.
The two controls that prevent it
What most pages miss is the connection to the specific OSHA controls that stop these injuries:
- Machine guarding (OSHA 29 CFR 1910.212). Fixed barrier guards, interlocked guards, presence-sensing devices, and two-hand controls keep hands out of the point of operation and cover pinch points, gears, and rotating shafts. A guard that shuts the machine down when opened removes the temptation to reach into moving parts.
- Lockout/Tagout — LOTO (OSHA 29 CFR 1910.147). Before anyone clears a jam, cleans, or services a machine, its energy sources (electrical, hydraulic, pneumatic, mechanical, stored) must be shut off, isolated, locked, and verified as zero-energy. LOTO exists precisely because the most common serious injuries happen during unexpected start-up or release of stored energy during maintenance.
Together these controls address the whole problem: guarding stops routine contact during normal operation, and lockout/tagout protects the worker during the jam-clearing and servicing tasks that cause the worst injuries.
The bigger picture
Other hazards exist—slips near machinery, flying chips and sparks, noise, and repetitive strain—but the caught-in/caught-between and amputation injuries from unguarded moving parts are consistently among the most common and most severe machine-related harms. The prevention hierarchy is clear: guard the machine first, and never put a body part into a machine that has not been fully de-energized and locked out. If you can reach a moving part, the machine is not adequately guarded.
- 1
Notify & prepare
Tell affected workers the machine is going down for service and identify all energy sources.
- 2
Shut down
Turn the machine off using its normal stopping procedure—never reach in while it runs.
- 3
Isolate energy
Disconnect or isolate every energy source: electrical, hydraulic, pneumatic, mechanical, and stored.
- 4
Lock and tag
Apply your personal lock and tag to each isolation point so it cannot be re-energized.
- 5
Release stored energy
Bleed, block, or discharge any residual pressure, springs, or capacitors.
- 6
Verify zero energy
Try to start the machine and test that it stays dead before reaching in to clear the jam.
Frequently asked
What is machine guarding?
Machine guarding is the use of physical barriers or safety devices—fixed guards, interlocked guards, presence sensors, two-hand controls—to keep workers from contacting dangerous moving parts like the point of operation, pinch points, and rotating shafts. It is required under OSHA 1910.212.
What is lockout/tagout?
Lockout/tagout (LOTO), OSHA 1910.147, is the procedure for shutting off and isolating a machine's energy sources, then locking and tagging them, before cleaning or servicing. It protects workers from unexpected start-up or release of stored energy during maintenance.
What are caught-in or caught-between hazards?
These occur when a worker's body or clothing is caught, crushed, pinched, or drawn into moving machine parts—such as gears, rollers, belts, or between a moving and a fixed part. They are a leading cause of amputations and are prevented by guarding and LOTO.
How can machine injuries be prevented?
Guard all dangerous moving parts so hands cannot reach them, and always use lockout/tagout to fully de-energize a machine before clearing a jam or servicing it. Add training, no loose clothing or jewelry, and never bypass a guard or safety interlock.