Plant Safety Through Lockout/Tagout Procedures

Sept. 28, 2010

In order to prevent the unexpected energizing or startup of machinery or equipment during servicing or maintenance, a lockout/tagout plan must be custom-tailored to each facility.

In order to prevent the unexpected energizing or startup of machinery or equipment during servicing or maintenance, a lockout/tagout plan must be custom-tailored to each facility.

Developing a Lockout/Tagout Plan for Your Facility

Lockout/tagout regulations require employers to establish in writing a lockout/tagout (energy control) program that establishes safe energy control procedures to prevent the unexpected startup or energization of equipment, or the unexpected release of stored energy while servicing or providing maintenance to machines and equipment. The most common types of potentially hazardous energy include:

  • Electrical
  • Mechanical
  • Hydraulic
  • Pneumatic
  • Chemical
  • Thermal
  • Gravity

The lockout/tagout (energy control) program must also include a documented employee training program and periodic inspections of the energy control procedures. The following sections provide a step-by-step process that is intended as a guide for developing and implementing a customized lockout/tagout program for your facility. This article is not intended to be a prescriptive legal document, but rather to highlight obvious requirements in the federal regulations that apply to HMA facilities. The ultimate test is whether the program is effective in preventing injury.

Purpose, Scope, and Responsibility

Develop and include provisions in your program that spell out the purpose, scope and intent of the lockout/tagout program and who will be responsible for ensuring implementation of the established procedures.

Next, survey your machines, equipment and processes and identify potentially hazardous energy sources from each. The results of the survey provide the authorized employees with an overview of all equipment, machinery and energy sources that must be locked out to be safe while employees perform maintenance. Authorized employees are the individuals who are charged with the responsibility for implementing the energy control procedures and performing the maintenance. The documentation should include the equipment to be locked out, the energy source, the type of energy isolation device, and its location.

Once the documentation is completed, list the specific procedures for shutting down and securing equipment to prevent unexpected release of stored energy. The procedures must include the following elements:

  • Statements on how the procedure will be used.
  • Necessary procedural steps to shut down equipment.
  • Steps designating the safe placement and transfer of the lockout/tagout devices and the authorized employees who have the responsibility for them.
  • Specific requirements for testing equipment to verify the effectiveness of locks, tags and other energy control measures.
  • A requirement that the authorized employee must notify the affected employees before lockout or tagout devices are applied and after they are removed from the equipment.
Protecting employees

When an energy isolating device can be locked out, it should be locked out unless the employer can demonstrate that the use of tags will provide protection at least as effective as locks and will assure "full employee protection." The employer must take extra measures to provide a safe work situation. Both lockout and tagout should be employed where possible.

The lockout and tagout devices must be identified as the only devices used for controlling hazardous energy and must meet several requirements relating to durability, standardization, substantial construction, and identifiability.

Materials and hardware such as locks, hasps, tags, chains, wedges, or safety pins that are specified for effective lockout are to be made available by the employer. The location of such hardware should be specified in the procedure.

Restoring Equipment

List the specific steps for restoring equipment to service safely. As a minimum, before lockout or tagout devices are removed and energy is restored to the equipment, the energy control procedures need to ensure the following steps are taken:

  • Machines or equipment components are operationally intact.
  • Employees are safely positioned away from the equipment.
  • Lockout or tagout devices are removed from each energy-isolating device by the employee who applied the device.
Training of Employees

Training is an essential part of an effective lockout/tagout program. The goal of training should be to provide the skills and knowledge that are required for safe application and removal of energy controls. Federal regulations are specific as to the training that must be done.

The specific training requires that:

  • Each authorized employee must receive training to be able to recognize the hazardous energy sources, the type and magnitude of the energy available in the workplace, and the methods necessary for energy isolation and control.
  • Each affected employee must be instructed in the use of the energy control procedures.
  • All other employees who may be working in the vicinity must be instructed about the energy control procedures and the prohibition regarding any attempt to restart equipment that is locked out or tagged out.
  • If tagout procedures are utilized where no physical lockout capability exists, employees must be trained in the limitations of the tags.

Company documentation of training/retraining is an essential part of a lockout/tagout plan. At a minimum it should include the employee's name and dates when training was done.

Annual Periodic Inspections

Federal regulations require employers to conduct periodic inspection/review of the lockout/tagout procedures for energy control at least once a year. This inspection must be performed by an authorized employee other than the individual who utilizes the control procedures being reviewed. The purpose of the periodic inspections is to correct any inadequacies identified through training efforts. A review with each authorized lockout/tagout person is required along with appropriate documentation of the equipment on which the review procedure was utilized.

Testing of Equipment

OSHA allows the temporary removal of locks or tags and the re-energization of the machine or equipment ONLY when necessary under special conditions. An example may be when power is needed for the testing or positioning of a machine. Precautions relating to the safe restoration of power to machines and equipment should be followed.

The on-site employer and the outside employer must inform each other of their respective lockout/tagout procedures. Employers must ensure that their personnel understand and comply with all restrictions of the other employer's lockout/tagout program.

When servicing is performed by a group of people, they must utilize a procedure that affords the employees a level of protection equivalent to that provided by a personal lockout or tagout device.

Specific procedures need to be developed and utilized during shift or personnel changes to ensure the continuity of lockout or tagout protections, including provisions for the orderly transfer of lockout or tagout device protection between departing and incoming employees.


This article is designed to assist hot-mix asphalt facility owners and operators with the development of lockout/tagout plans and programs for their facilities that are designed to meet the intent of federal regulations. As always, it is a good idea to compare federal regulations with state regulations and requirements to ensure compliance with both.

This article represents highlights from NAPA's publication Lockout/tagout Plan Guidance (HS-12). The publication contains forms, checklists and additional regulations that will be helpful in your lockout/tagout procedures. To order, go to the NAPA website at, or call 888-468-6499.

Reprinted from HMAT magazine with the permission of National Asphalt Pavement Association,