This section provides an overview of the most common 
hazards in the workplace related to lock-out and/or tag-out systems.  

A lock-out and tag-out System should be used when there is a potential for equipment or machinery to endanger workers in or around the worker due to an accidental start up or from the release of stored potential energy. 

The most common hazards that may be associated with performing maintenance, servicing of equipment, removing or bypassing safeguards are:

1. Electrocution - working on any machinery is hazardous, especially since you may come in contact with wires that may become live if proper lock-out procedures are not followed.  Electrocution is one of the main causes of death. 
2. Cuts and Lacerations - many people receive deep cuts or lacerations when trying to escape from machinery that has been energized while they were inside it.  Many of these injuries can become life threatening due to infections that may develop.  It is important to report and receive treatment for any injury, no matter how small, as it can become more serious.
3. Entanglement in moving parts of Machinery - one of the most common types of injury is being caught, entangled or pinched by moving machinery (chains, cogs, rollers, presses, etc.) that has not been locked out properly, or that was accidentally re-energized. This type of injury usually results in the loss of fingers, hands, arms, feet and legs.  It is therefore very important to follow all lock out procedures carefully, and to ensure that there will be no movement or tensing up of machinery parts.
4. Entrapment/Engulfment by Bulk Material (Liquid or Solids) - when working on industrial equipment, it is important to ensure that the area is clear and barricades are put in place so no materials can fall into the worksite, or block the entrance.  Many people are killed each year because they were crushed by loose materials, or suffocation occurred because the exit point was blocked.  In addition, make sure that all machinery that feeds into the equipment that you are working on is also locked out.
5. Drowning in Liquids - always check to ensure that the work area is dry and that all sources of liquid flow are blanked off to prevent any build up of liquid.  When working in a confined space, ensure that all emergency rescue procedures are in place.  Drowning is a common cause of death when lock-outs are not performed.
6. Burns - contact with skin or body parts on hot surfaces are common working hazards while working on hot machinery.  These burns can be avoided by allowing for adequate time for the equipment to cool to an acceptable level.  Other causes are due to coming in contact with hot pipes, and leaking valves containing heated materials.  All pipes must be blocked off and bled before starting your work.
7. Fire and Explosion - if proper lock-out procedures are not followed fires and explosions they may cause a hazard. This may be caused by the use of flammable or combustible materials, or by an oxygen-enriched atmosphere.  Electrical arcs or sparks can easily ignite many materials, and can lead to an explosion.  This risk is increased when working in confined spaces.
8. Chemical Exposure - exposure to chemicals in liquid, solid or gaseous form may cause severe injury, illness and death.  This is true when working around pipelines and storage tanks. Following the proper lock out and blanking procedures will reduce or eliminate these risks.  These procedures include wearing the proper personal protective equipment and becoming familiar with all chemicals that are present at the site.

These are only a few examples of what may happen if a Lock-out and Tag-out System is not used. When determining the correct Lock-out and Tag-out System, consideration must be given for all of the energy sources and activities that will be conducted in or around the locked out area. Virtually all of the accidents associated with performing service on machinery could have been avoided by following proper procedures and safety rules.  Common sense also plays an integral role when identifying potentially dangerous situations and preventing accidents.  Listed below are the main causes for lock-out/Tag-out accidents:

• Working on equipment that is still running.
• Failure to disconnect the power source and de-energize the equipment.
• Not releasing built up or residual energy.
• Accidental restarting of equipment by another worker.
• Restarting equipment without ensuring that the area is clear.