Machinery Lock-out Procedures that Work

Our friend Chris Miranda from Mac Safety Consultants has some advice on how to avoid machinery risks and save lives. Follow his six safety steps and create your own lock-out procedure.

Every year, people are killed on the job by activated machinery.  Many of those deaths could have been prevented by following lockout/tagout procedures to turn off machinery that is being serviced or repaired.

Here are some real-life examples:

•     An untrained worker was feeding scrap cardboard into a shredder.  When the shredder jammed, he tried to fix it without turning off the machine.  His arm got caught, was pulled into the shredder, and he bled to death.

•     A worker was inside a cement mixer, cleaning it.  Another worker, who didn’t know anyone was inside the machine, turned it on and the worker inside was killed.

These tragic examples of accidental death could have been prevented by following lockout/tagout procedures. They also make it clear that everyone has to be aware of the importance of shutting off power to machinery when it’s being fixed, cleaned, or maintained.  Even if you don’t operate heavy equipment, you could accidentally get in its way if it’s not properly disconnected.  So, let’s review and practice basic lockout/tagout procedures to make sure no worker is ever killed or injured by equipment that should have been shut down.

Any powered machinery or electrical equipment that could move in a way that would put people in danger is a hazard that can be prevented by lockout/tagout.  You also have to be alert to equipment that could roll, fall, or move onto a person after it’s shut down.

Hazards occur during the following circumstances:

•     Repair

•     Maintenance

•     Cleaning

•     Mechanical or operational problems

•     Machinery that’s thought to be fully turned off but isn’t.

The bottom line here is simple:  Never try to clean, repair, or perform maintenance on any piece of machinery or equipment without completing lockout/tagout.  There’s a second bottom line, too, that applies to everyone who even gets into the vicinity of a machine:  Don’t touch, much less operate, any piece of equipment or machinery unless you are trained and authorized to do so.  Don’t touch anything that’s locked and tagged unless you are responsible for working on it and are sure the power is disconnected.

The key point of lockout/tagout procedures is to shut down completely machinery and electrical equipment before repair, maintenance, and cleaning.  Here’s the six-step shutdown procedure:

1.   Before shutdown. The authorized employee must know the type and magnitude of the energy, the hazards of the energy to be controlled, and the method or means to control the energy.  The authorized employee must notify all affected employees of the lockout.

2.   Shutdown. The authorized employee shuts down the machine or equipment by the normal stopping procedure, such as pressing the stop button, moving the switch to the “off” position, etc.

3.   Isolation. The main power switches, circuits, or additional sources of energy are moved to the “off” position or otherwise made inoperative.

4.   Lockout. Locks are placed on switches or other energy sources in the “safe” or “off” position.  During a group lockout, all members of the group must add their own locks to the group lockout devices and should never place a lock inside another individual’s lock.  Warning tags should be placed with each lock.

5.   Energy release. All potentially hazardous stored or residual energy, such as that in springs, elevated parts, rotating flywheels, hydraulic systems, electrical systems, and air, gas, steam, or water pressure, etc., is relieved, disconnected, or otherwise made safe by repositioning, blocking, bleeding down, etc.  If there is a possibility of reaccumulation of stored energy to a hazardous level, verification of isolation must be continued until the servicing or maintenance is completed or until the possibility of such accumulation no longer exists.

6.   Testing. After making sure that no personnel are exposed, and as a check on having disconnected the energy sources, the authorized employee operates the push button or other normal operating controls to make certain the equipment will not operate.

CAUTION: Return operating controls to the “neutral” or “off” position after the test.  The equipment is now locked out.

Tagout is the process of placing tags on machinery to warn workers not to start or operate the equipment.  It usually occurs after lockout and is a way of making doubly sure that other workers know to stay away from the machinery.  Tagout is not a substitute for lockout.  However, in cases where machinery cannot be locked out, tagout becomes extremely important because it is the only way to warn other employees that the equipment should not be used.  Tagout alone should be used only with management approval.

When maintenance or service is done, only the same authorized employee who installed the lock may remove it.  Special circumstances may apply during shift changes and when an employee who placed a lock or tag is not available to remove it.

Usually, this involves a designated worker who must notify the person who locked out a machine that the lock is being removed.   For safety, follow your company’s procedures in these situations.

Once servicing is complete, follow these steps:

1.   Check all around the machine to make sure that all maintenance items have been removed and that the equipment components are operationally intact.

2.   Check the work area to make sure all employees are removed from the area and cannot enter during this phase.

3.   Verify that the controls are in neutral.

4.   Remove the lockout devices and reenergize the machine.

5.   Notify the affected employees that the servicing is completed and the machine is ready for use.