Hazardous Energy Control (Lockout/Tagout)

Originally published Aug. 19, 2015

Effective lockout/tagout programs protect employees from serious or fatal injuries that could occur during an unexpected release of energy while servicing machinery or equipment.

Stored energy from many systems (electrical, mechanical, pneumatic, chemical, nuclear, thermal and gravitational) can cause injury.

Let’s discuss what happened when a rock crusher malfunctioned on a worksite, allowing large pieces to pass through the conveyor. A worker stopped the conveyor, climbed onto the catwalk and began pushing the large pieces off the conveyor belt. Another large piece of concrete rolled down the conveyor as the worker reached to remove the first piece, crushing his hand. Other workers reported the conveyor belt back traveled, possibly causing large chunks of debris to dislodge and roll.

This example demonstrates two different forms of energy – gravity and mechanical. Falling or rolling objects and unexpected machine movement can crush or trap you. Machine movement can even pull you into the workings of the machine. The worker in our example should have stopped and locked the machine before dislodging the concrete.

Workers should learn appropriate lockout/tagout procedures and follow them.

  • Look around you. Make sure you understand the different kinds of energy that could harm you. Think about the obvious things, like gravity.
  • Turn off controls.
  • Disconnect machines from their power source.
  • Tell others what you are doing.
  • Dissipate (bleed or neutralize) residual energy.
  • Clear work areas, and warn others before you restart the equipment.

Thousands of injuries occur every year because workers didn’t follow the appropriate lockout/tagout procedures. Don’t be one of the statistics.


Gravity is the natural force that attracts objects toward the center of the earth or each other. This is the force that pulls us down when we fall or jump, and it’s constant. You might be thinking, “Everyone knows this; it’s just common sense.” We may know it, but we don’t always think or plan ahead to find ways to prevent ourselves from falling victim to gravity’s force.

These circumstances resulted in falls on worksites:

  • A worker finished rigging material on a flatbed truck for unloading. While he was walking across the load to get off the truck, the worker slipped and fell – landing on a load of I-beams.
  • A worker drove a machine onto an uneven and unstable surface, which caused the machine to tip over. The worker jumped and broke both wrists when he landed on the ground.
  • A worker stepped on a catwalk grating that was not properly secured to the catwalk frame. The grating flipped up and created an opening that the worker fell through. The worker injured his hands and fingers trying to grab onto the catwalk frame.
  • A worker walked across a mat of rebar and tripped, falling onto the rebar and injuring his knees and hands.

In each of these instances, the workers were on surfaces that were uneven, not properly secured or had obstructions – creating the perfect opportunity for the worker to lose his or her balance and fall.

Also, remember to use a set of stairs or a ladder to come down from a surface. Jumping may be faster, but jumping creates a greater chance for injury. The impact when you land can cause damage to your knees, hips and back. You may negate the time you save by jumping with a subsequent week-long absence due to injury.

We can prevent many falls if we just think ahead.

  • Is the surface area level and cleared?
  • What kind of surface is below?
  • What is the risk of injury?

A jump or fall may be short-lived, but the possible injury could last the rest of your life.