The Lockout Standard of OSHA for industry includes lockout requirements for the servicing and maintenance of machines and equipment and any associated activities. Normal production operations are not covered by the standard unless an employee is required to remove or bypass a guard or other safety device, or they must place any part of their body into the point of operation of a machine or piece of equipment. Operating personnel and the tasks they perform are covered if that employee is exposed to an associated danger zone during an operating cycle.
Hazardous energy comes in many different forms and types. These may be hydraulic, pneumatic, mechanical, thermal, radioactive, electrical, or chemical energy. In addition, the effects of gravity must be considered. Hydraulic energy is the use of fluids to accomplish work within a closed system and may generate tremendous pressures. The same can be said of pneumatic energy. This is the use of air to accomplish similar tasks.
Mechanical energy is the physical movement of machinery while thermal energy is a source of heat. Radioactive sources are used in many measuring and monitoring systems and must be strictly controlled.
Electrical energy is the flow of current through conductive materials and is measured in amperes and voltage. Chemical energy may be in the form of liquid, solid or gaseous materials that may cause injury upon contact or release large amounts of energy if mixed with other materials. Each of these may be in one of two states, active or stored. Let’s review some of the examples of each of these states of energy.
A good example of active energy would be a live electrical connection powering a mechanical device that if contacted may produce severe injury. The same energy also may be in a stored form such as within a capacitor. No current is flowing, however, if the capacitor was touched by a conductive material such as a tool or a part of your body, the electrical energy may cause injury.
If we review a few of these forms, we find that pneumatic or compressed air systems may have high-pressure air held within the tank that must be controlled by turning the electric motor switch to the OFF position and locking the electrical disconnect into the open position. We must then release the compressed air stored in the tank by carefully opening a valve on the tank to release the stored energy. The valve must then be locked in the open position if buildup of air pressure is possible.
You must know the types of energy sources in your workplace and their states in order to ensure the control of each through lockout.
Learn more about Lockout/Tagout with these resources: