Cleaning Safety: Stop, Cut Power, Lock Out and Tag Out

Must Power Be Cut for Cleaning?

Absolutely. Just pressing the stop button on the control panel isn't enough, because:

• Someone else might press start while your hand is inside the machine.
• A control system fault or sensor misreading could make the machine move on its own.
• Some mechanisms retain residual pressure, spring force, or inertia after stopping.

Article 57 of the Occupational Safety and Health Facilities Rules (職業安全衛生設施規則) requires that where cleaning, oiling, inspection, repair, or adjustment of machinery, equipment, and related accessories could endanger workers, the employer must:

1. Stop the operation and feeding of the relevant machinery.
2. Take measures such as locking out and posting signs to prevent accidental operation of start-up devices or accidental feeding.
3. Provide safety equipment and measures to prevent hazards from falling objects.

The same article also requires that before such work, a hazard prevention plan be drawn up based on site conditions, covering hazard identification, assessment and control, work methods, work permit procedures, and safety check methods, and be communicated to the workers involved; when machinery is stopped or disassembled for repair and there is a residual pressure hazard from springs, hydraulics, pneumatics, or vacuum accumulators, measures must be taken to release pressure, shut off, or isolate it. Where work must be done while the machine is running, hazardous parts must have guards or enclosures, or sufficiently long work tools must be used.

What Is Lockout/Tagout?

Lockout/Tagout (LOTO) makes "cutting the power" impossible for anyone else to override:

• Lockout: Use a personal safety lock to lock the power switch, circuit breaker, or air valve in the "off" position. You keep the key, so no one else can open it.
• Tagout: Hang a tag on the lock stating who, when, and what work is being done, for example "Cleaning in progress, do not operate."

Article 276 of the Occupational Safety and Health Facilities Rules also covers the electrical side: when power is cut to adjust electric machinery, the switch must be locked or tagged and signed immediately after being cut off; to restore power, the person who signed the tag must remove the lock or tag before power is restored.

Lockout/Tagout Steps

1. Notify: Tell the relevant people on site that this machine is being stopped for cleaning or maintenance.
2. Normal shutdown: Stop the machine through the normal procedure on the control panel.
3. Isolate energy sources: Turn off the main power switch; close air valves and bleed pressure where there's an air supply; close valves for steam or hot water.
4. Lock and tag: Every person involved in the work attaches their own lock; for group work, use a multi-lock hasp.
5. Release stored energy: Bleed off air and hydraulic pressure, let rotating parts come to a complete stop, and secure any parts that could fall if necessary.
6. Verify: Press the start button to confirm the machine really won't move, then return the switch to off.
7. Work: Begin cleaning or maintenance.
8. Restore: When the work is done, count tools and parts, reinstall guards, tell the relevant people to leave the danger zone, have each person who applied a lock remove their own lock and tag, and then restore power for a test run.

For small tabletop machines, unplugging the machine and keeping the plug where the worker can see it and others can't reach it is also a form of isolation.

Common Cleaning Accidents

• Mixer entanglement: Reaching or leaning into the bowl to clean it when the machine is started. A 2023 occupational safety alert from Hong Kong's Labour Department recorded a case in which a food factory worker fell into a mixing bowl and was fatally crushed by the rotating mixing arm; its recommendations included switching off and locking the power supply during inspection, maintenance, and cleaning, posting warning notices, and implementing a permit-to-work system.
• Roller entanglement: Wiping a running dough sheeter roller or conveyor drum, and the glove or cloth gets caught and pulls the hand in.
• Blade cuts: Getting cut while removing meat grinder blades or vegetable cutter discs; blades hidden in a sink full of water during washing.
• Electric shock: Water getting into electrical parts that haven't been de-energized during hosing.
• Chemical injuries: Detergent splashing into eyes, or mixing bleach with acidic cleaners and producing chlorine gas.
• Slips: Wet, greasy floors after cleaning.

Safety Habits

• Cut power and lock out before cleaning; don't trust "I'll only be a second."
• Wear appropriate protective equipment: waterproof gloves, safety goggles, slip-resistant shoes.
• Keep bladed parts separate and wash them separately.
• Article 279 of the Occupational Safety and Health Facilities Rules: where hair or clothing could be caught, appropriate clothing and headwear must be worn.

FAQ

Q: Is it enough to just press the stop button when cleaning a machine?
A: No. Turn off the main power and lock out and tag out to prevent others from starting it accidentally.

Q: What is lockout/tagout?
A: Using a personal safety lock to lock the energy source switch in the off position, and hanging a tag stating who is working and what they're doing.

Q: Who can remove the lock?
A: The person who applied the lock and tag. Article 276 of the Occupational Safety and Health Facilities Rules requires the person who signed the tag to remove the lock or tag when restoring power.

Q: Do small tabletop machines need to be locked out too?
A: At minimum, unplug the machine and keep the plug where you control it, making sure no one else can plug it back in and start it.