The lockout tagout concept is designed to improve safety for those servicing or maintaining machines and other essential equipment. If used properly, LOTO will prevent unexpected energization or the engagement of a machine while someone is in a vulnerable position. It also prevents the release of any stored power, which has the potential to injure or kill those working in the area.
While the idea behind the lockout tagout concept is fairly simple, it is extremely effective for improving the safety of people working in what could otherwise be an extremely dangerous job.
What Is Lockout/Tagout?
The lockout tagout system, which is sometimes called "control of hazardous energy," or LOTO, is a strategy that attempts to eliminate all energy from a particular piece of equipment by placing a tag and/or lock on the equipment after shutting it off. It is used when servicing equipment, which often involves maintenance personnel going into areas that could be deadly should the machine engage.
While each specific process will be unique, generally the individual who will be working on the machine uses lockout tagout procedures and disconnects all sources of energy. This includes the main power source, any backup power sources including battery backups, and then ensuring that any stored energy has been released.
Once the power has been disconnected, the maintenance personnel places a physical lock on the power source making it impossible to restore power. Only the individual working on the machine has the key to the lock, preventing anyone else from restoring power at the wrong moment. This is important because it helps ensure that the person actually doing the dangerous work is responsible for his or her own safety.
In many cases there will be more than one employee working on a particular system. When this occurs, each employee applies his or her own lock or tag to the source of the power. When one employee completes their work, they should only take off their specific lock. This is especially important because it helps avoid any confusion or mistakes that can lead to machines being powered up when there are still people inside.
Types of Hazardous Energy
When most people think about hazardous energy, they only consider electricity. While electrical energy is extremely dangerous and likely the most common hazard the lockout tagout procedure is used for, there are several other types of energy sources to be aware of. Understanding each hazardous energy source is important when identifying where the lockout tagout system needs to be implemented in a facility. Those other energy sources include:
Electrical Energy – When establishing lockout tagout procedures for electrical energy, it is important to know the potential sources. For most machines and equipment, the electrical energy flows through a circuit breaker of some sort. This is the location where the lock can be placed to prevent electrical energy from flowing into the machine.
Common LOTO Procedures: In some cases, simply unplugging the machine and applying the lock there can be effective. For heavy machinery, however, this is often difficult or impossible due to the size of the electrical cables. Start by determining every potential source of electrical energy and then determine exactly where and how the energy can be removed and secured.
Mechanical Energy - Mechanical energy is often overlooked when working on machines and it can be quite dangerous. This type of energy is created through the motion of an object. In the context of a lockout tagout system, mechanical energy may become an issue if an employee working on a machine bumps a movable part, causing it to pick up momentum and become dangerous.
LOTO Procedures: Locking robot arms, movable saw blades, crushing parts, and anything else that moves is a good way to reduce any risk from mechanical energy. It is important to ensure things don't move unexpectedly and prevent mechanical energy from being released inadvertently from a bump or other event.
Hydraulic Energy - Machines often operate using hydraulic energy as it can be extremely effective for heavy machinery. If the hydraulic oils are under pressure when someone is working on a machine, the potential is there for it to become released, causing the machine to activate. In some cases, the hydraulic oil is kept under pressure with electrical brakes, which will disengage when the power is cut.
LOTO Procedures: If a machine uses hydraulic energy of any type, part of the lockout tagout procedure should involve checking to ensure the energy has been released before working on the machine. It is not acceptable to enter a potentially dangerous area when there is energy like this built up, even if it is not likely to be released.
Pneumatic Energy - Another type of energy to be aware of is pneumatic energy. It is somewhat similar to hydraulic energy, except it is formed using pressurized air. Some machines use pressure tanks to build up energy in the machine before it is needed. If a machine utilizes pneumatic energy for any purpose, a lockout tagout procedure should always include the discharging of pneumatic energy before beginning a job.
LOTO Procedures: To make sure that there is no stored energy within a pneumatic powered machine the maintenance worker may perform a test by trying to operate the machinery after it has been locked out. This should only be done after ensuring everyone involved in the maintenance is well away from the area before the test occurs. The gauges should indicate zero pressure upon a successful test.
Chemical Energy – This energy can be stored and released through chemical reactions. Whether this occurs due to the mixing of two or more chemicals, a change in temperature of chemicals, a change in pressure, or any number of other situations, it is a concern.
LOTO Procedures: One of the most common examples of chemical energy includes the burning of gasoline in internal combustion engines. When dealing with lockout tagout systems, there may be a diesel generator providing backup power that would need to be removed and locked out. Identifying all potential sources of chemical energy in a machine and removing or securing them is essential for a good lockout tagout program.
Thermal Energy - Thermal energy is energy in the form of heat. This could be heat from the sun, from the burning of something, or a number of other things. Modern machines don't often directly use this type of energy, but it is a good idea to be aware of it. If a machine can become active from thermal energy, it too must be removed and secured before any work can begin.
LOTO Procedures: One of the best routes for protecting employees from this type of hazardous energy is to check and see if the machine becomes hot when it has power.
Creating Machine-Specific Procedures
The lockout tagout process is unique for every machine across all industries. Some machines have just one power source, while others have multiple. Because of this, when using lockout tagout programs in a facility, it is important to make sure detailed instructions are written and followed for every single machine.
In most cases, the best way to do that is to create a step-by-step checklist that everyone who works on a machine can follow. Having checklists is a great way to guarantee everything is done correctly and in the proper order, which is critical for safety when working on potentially dangerous machines.
Steps to a Lockout/Tagout Procedure
When creating a lockout tagout procedure for a machine, it is important to include the following items. How these items are covered will vary from situation to situation, but the general concepts listed here should all be addressed in every lockout tagout procedure:
- Notification - All employees who work with or around a machine should be notified of any scheduled maintenance.
- Visual Communication - Put up signs, cones, safety tape, or other forms of visual communication to let people know that a machine is being worked on.
- Energy Identification - All sources of energy should be identified prior to creating a lockout tagout procedure. The procedure should account for every possible energy source.
- How Energy Is Removed - Determine exactly how the energy should be removed from the machine. This could be simply unplugging it or tripping the circuit breaker. Choose the safest option and use that in the procedure.
- Dissipate Energy - After energy sources have been removed, there will be some amount left in the machine in most cases. "Bleeding off" any remaining energy by attempting to engage the machine is a good practice.
- Secure Movable Parts - Any parts of the machine that can move and result in injury should be secured in place. This can be done through built-in locking mechanisms or finding alternative ways to secure the parts.
- Tag/Lock Out - All employees who will be working on the machine must individually apply a tag or lock to the energy sources. Whether it is just one person or many, it is essential to have one tag for each person working in a potentially dangerous area.
- Engagement Procedures - Once the work has been completed, procedures should be in place to confirm all employees are in a safe location and that any locks or safety equipment have been removed before powering the machine up.
- Other - Taking any additional steps to improve the safety of this type of work is very important. All workplaces should have their own unique set of procedures that apply to their specific situation.
Creating a lockout tagout procedure doesn't have to be difficult, but it should be as detailed as possible to get the desired effects. When proper planning is put in place, the risk of injury for those working on machines can drop.
Understanding Lockout/Tagout Programs
Understanding this type of program comes down to training employees on the correct precautions and procedures that they must take to stay safe and prevent unexpected releases of hazardous energy. Employee training for both affected employees and LOTO authorized employees should always occur before servicing and maintenance activities begin for those who are new to LOTO.
Retraining for these procedures should take place when employees have:
- Different job assignments
- A change in energy control procedures
- A new machine or process that presents new hazards.
OSHA regulations that specify training requirements can be found in section 1910.147.
Why is LOTO Important?
OSHA reports that facilities that comply with standard lockout/tagout programs help prevent approximately 120 workplace deaths each year and around 50,000 additional injuries. However, even with those statistics accidents that cause injuries and fatalities related to hazardous energy and stored power occur far too often. This is because these employees often work in areas that are otherwise forbidden due to their high level of danger.
While the lockout tagout process may seem excessive at first, people quickly realize how important it is. When working with dangerous machines, even a small mistake or oversight can mean the difference between life and death.
For those who need to create a business case for adding lockout tagout procedures in a given situation, consider the following: OSHA has found that the average worker injured by hazardous energy releases ends up missing 24 days of work for recuperation. This setback is in addition to the potential expenses associated with medical coverage or even a possible lawsuit.
Lockout Tagout Products
A number of options exist for implementing lockout tagout procedures in a facility. Some facilities choose to create their own systems using custom products and equipment. This can be effective as long as everything follows OSHA standards and other proven best practices.
The majority of facilities choose to use proven lockout tagout supplies that are made specifically for this type of procedure. Due to the proven success of lockout tagout, there are many products that can be used to help improve safety in this area.
In addition to making lockout tagout more effective, these products also make the steps of lockout tagout easier to follow. Employees who have the right tools and products to complete this procedure will be able to do so more quickly, which eliminates any wasted time or effort.
Personal Protective Equipment Is Still Important
The lockout tagout procedures are very effective when they are followed properly. As with any procedure, however, it is not 100% foolproof. This is why it is still recommended that all employees working in dangerous areas still wear the proper personal protective equipment.
Having PPE available and worn correctly and consistently will help further reduce the risk of employees experiencing serious or even fatal injuries. By implementing effective lockout tagout procedures, using personal protective equipment, and encouraging all employees to use extreme caution, the risk of accident and injury in these situations can begin to approach zero.
- Lockout/Tagout Program (How To Control Hazardous Energy)
- Forklift Safety Procedures
- Arc Flash PPE
- Arc Flash and Electrical Safety
- Keeping Operators Safe with Machine Guarding
- Arc Flash [Facts, Safety Requirements & PPE]
- Confined Space Hazards
- Fire Prevention in the Workplace [OSHA 1910.39]
- Hierarchy of Controls [Hazard Exposure + Prevention]