Failure to lock out and block out machinery before working on it is a major cause of serious injury and death. According to the American Society of Safety Engineers, statistics indicate that millions of workers nationwide are at risk of injury from equipment, machinery or processes that do not implement proper lockout/tagout LOTO procedures.

The new A10.44 standard recognizes the need for protection of personnel and property from injury due to unexpected start-up or release of stored energy from equipment, system/process or induced
energy during repair, maintenance, operation, installation and other activities involving machines or equipment. The ANSI 10.44-2006 standard is one of a series of standards that focus on construction
and demolition operations.

Whether on a construction site, or a manufacturing facility, consider the following information regarding lockout/tagout safety from the California Dept. of Industrial Relations’ Dept. of Occupational
Safety and Health: Lockout/blockout means that any energy source — whether electrical, hydraulic,
mechanical, compressed air or any other source that might cause unexpected movement—must be disengaged or blocked, and electrical sources must be de-energized and LOCKED or positively
sealed in the OFF position.

But even a locked-out machine may not be safe if there are parts of the machine that are not BLOCKED to prevent inadvertent movement. Potential energy that may need to be blocked can come
from suspended parts, subject to gravity, or energy stored in springs. In a U.S. Bureau of Labor Statistics study on injuries related to servicing equipment, 80 percent of the workers surveyed failed to even turn off the equipment before performing the service work.

There is a difference between turning off a machine and actually disengaging or de-energizing a piece of equipment. When you turn off a control switch, you are opening a circuit. There is still electrical
energy at the switch, and a short in the switch or someone inadvertently turning on the machine may start the machine running again.

Statistics show that of the 20 percent of workers who did turn off the machinery, about half of them were injured when someone, generally a coworker who was unaware that the machine was being serviced, accidentally reactivated the machinery.

And a fifth of those workers who turned off the control switch were injured by the energy still in the machine, which should have been blocked. The moving parts of the machine either continued to coast, or the parts moved when the jam-up was cleared.

An accident in California illustrates this problem. A table saw was turned off, but the saw blade was still coasting and had not come to a complete stop. An employee began cleaning the machine, and his finger was amputated by the blade.

Other accidents have occurred when the control switch on a machine was turned off, but a short in the switch restarted the machine.

Accidents have also occurred even when workers did take the necessary steps of disconnecting the main power source. But they did not perform a crucial step for a complete lockout procedure.
They did not test the equipment to make sure the machinery was, in fact, de-energized.

In one case, the lockout had been done on the wrong power line. In another case, a second power line had been spliced into the wiring beyond the point of the lockout. To prevent these kinds of lockout/blockout accidents, General Industry Safety Order 3203 — in Title 8 of the California Code
of Regulations — requires every employer to inaugurate and maintain an accident prevention
program, which shall include but not be limited to the following:
1. A training program designed to instruct employees in general safe work practices, plus specific instruction with regard to hazards unique to any job assignment.
2. Scheduled periodic inspections to identify and correct any unsafe conditions and work practices that may be found. The employer shall correct unsafe conditions and work practices found as a result of the required inspections.

To be effective, a lockout/blockout program should include:
• A survey of the equipment by responsible persons who are thoroughly familiar with its operation and associated hazards, in order to identify which machinery should be locked and blocked out;
• Identification and labeling of lockout devices;
• Selection and purchase of locks, tags and blocks; and
• A standard operating procedure that is written and followed.

Equipment Survey:
Make an initial survey of the plant or operation to identify all energy sources. This must be done by physical inspection, possibly in combination with a study of drawings and equipment manuals.
Locate and mark the disconnecting means, indicating their function. Categorize the identification details as to equipment supplied and energy type and magnitude, from material worked out
beforehand.

A sign or sticker — “LOCKOUT HERE” — placed at the disconnecting means will help direct workers to correct lockout devices. After surveying the operation, additional and more practical
means may be installed. In complicated operations, schematics of just the disconnecting
means may need to be drawn up by the plant’s engineering department.

Methods of Locking Out Controls
There are many different ways to lock out a piece of equipment. Commonly, the main disconnect switch has one opening where a lock can be placed. If more than one employee works on
the equipment, a lockout adaptor suitable for the installation of several locks must be used, enabling all workers to lock out the machine with their individual locks.

If the switches are in a metal box, the box itself must be locked out. If a fuse was removed in order to de-energize the equipment, the fuse box must be locked.

If the controls are in a metal-covered box, a common hasp can be welded or riveted to the door, along with a lock staple. Then the switch can be “opened,” and the door closed and padlocked. Fuse
boxes can also be locked in this way.

Machines activated by compressed air or steam will have valves that control movement. These valves will need not only to be locked out, but also bled to release any back pressure.

Lockout Procedure Requirements
1. All maintenance personnel are issued a suitable lock (or locks). The lock has the individual worker’s name and other identification on it. Each worker has the only key to the lock.

2. The worker checks to be sure that no one is operating the machinery BEFORE turning off the power. The machine operator is informed before the power is turned off. Sudden loss of power could cause an accident.

3. Steam, air, and hydraulic lines should be bled, drained, and cleaned out. There should be no pressure in these lines or in reservoir tanks.

4. Any mechanism under load or pressure, such as springs, should be released and blocked.

5. Each person who will be working on the machinery should put a lock on the machine’s lockout device(s). Each lock must remain on the machine until the work is completed. Only the
worker who placed the lock should remove his/her lock.

6. All energy sources that may activate the machine must be locked out.

7. The main valve or main electrical disconnect must be tested to be sure that the power to the machine is off.

8. Electrical circuits must be checked by qualified persons with proper and calibrated electrical testing equipment. An electrical failure could energize the equipment, even if the switch is in the off position. Stored energy in electrical capacitators should be safely discharged.

9. CAUTION: Return disconnects and operating controls to the off position after each test.

10. Attach accident prevention tags, which give the reason for placing the tag, the name of the person placing the tag, how he/she may be contacted, and the date and time the tag was placed. No one removes the lock without proper authority.

Locks, Blocks and Tags
Each worker must have his/her own lock and the only key to that lock. The lock should be substantial and durable, and should have the name of the employee on it. In addition, locks can be color-coded to indicate different shifts or types of crafts.

When more than one worker is servicing a piece of equipment that must be locked out, a lockout adaptor can be used, which allows all the workers to place their locks on the disconnecting
means.

After the work is completed, each worker removes his/her lock and the machine is then returned to service.

Tags
DO NOT USE TAGS ALONE. Use tags or signs in addition to locks. Tags must state the:
• Reason for the lockout;
• Name of the employee who is working on the equipment and how that person may be reached; and
• Date and time the tag was put in place.

Tagout devices shall be capable of enduring at least 50 pounds of pull, and a non-reusable type.

Blocks
Suitable blocks are another important safety device for making a piece of equipment safe to be repaired or serviced. Blocks must be placed under raised dies, lifts or any equipment that
might inadvertently move by sliding, falling or rolling.

Blocks, special brackets or special stands such as those commonly used under raised vehicles, must be available and always used. Another form of blocking is the placement of a blind. A blind is a disk of metal placed in a pipe to ensure that no air, steam, or other substance will pass through that point if the system is accidentally activated.

Before installing blinds or blocks, bleed down steam, air or hydraulic lines to get rid of any pressure. Coiled springs, spring-loaded devices or suspended loads must also be released so
that their stored energy will not result in inadvertent movement.