High-Performance Lockout/Tagout

This lockout/tagout strategy goes beyond compliance to help ensure the elimination of serious injuries while encouraging high productivity.

Continuous advances in machine, equipment and process technology are making companies more efficient, productive and competitive -- necessary attributes in a global economy. As technology has advanced, however, the energy sources that drive machines have become more powerful and sophisticated, making service and maintenance tasks more demanding, complex and, often, more dangerous. While machine safeguarding has progressed, injury risks for those who operate, service and maintain equipment persist.

OSHA's lockout/tagout standard has been in effect since Sept. 1, 1989; yet, hazardous energy release incidents continue to occur. A recent Bureau of Labor Statistics study reported 189 workplace deaths caused by workers being caught in machinery in 1997, a 29 percent increase from the previous year. More than half of these fatalities occurred while workers were carrying out service- or maintenance-related tasks. In 1998, lockout/tagout violations ranked fourth on OSHA's top 10 list of most frequently cited standards (3,532 violations) and fourth on the top 10 list of serious violations (2,537 serious violations).

Despite the alarming number of machine-related accidents that have occurred, lockout/tagout is still viewed by many as a burdensome, production-slowing task. Companies that fail to recognize and control machine hazards face regulatory fines and risk the occurrence of a serious and costly machine-related accident. World-class companies maintain effective lockout programs to prevent these predictable losses.

While accidents involving improper lockout occur for various reasons, they can generally be attributed to management system failures. Management errors such as inadequate training, poor energy control procedures and a lack of lockout/tagout program emphasis increase the likelihood of accidents. With a high-performance lockout/tagout program, however, injuries and losses arising from failure to control hazardous energy are entirely preventable.

Elements of Success

The basic elements of a lockout/tagout program include conducting an application and exposure survey, developing a written program, developing machine-specific energy control procedures, provision of protective appliances, employee training and annual program/procedure review. While these basic elements may suffice for compliance purposes, additional elements are needed for the lockout/tagout program to be successful. These include:

Visible Management Leadership: Personnel must have the necessary authority and resources to meet their responsibilities. Protective appliances (e.g., locks, tags, blocks, pins, wedges and other lockout devices) must be provided and readily available. Lockout/tagout responsibilities should be well-defined, and managers should ensure that all requirements are properly executed.

Employee Participation: Employees should participate in the development of the energy control procedures that affect them. Such involvement fosters a sense of "ownership" and enhances understanding. Communication with, and feedback from, employees should be sought continuously to identify deficiencies in the lockout program, as well as opportunities for improvement.

Enforcement and Accountability: Injuries associated with improper lockout are often serious or fatal. Thus, personnel must be held accountable and understand the consequences for violating lockout/tagout procedures. Discipline should be initiated when lockout/tagout violations occur to bolster enforcement. Many companies have disciplinary policies in which progressive discipline steps are skipped and actions "up to and including discharge" are imposed, and when safety violations such as failing to follow lockout/tagout occur. This is because the risks associated with nonadherence to lockout procedures are simply too high to tolerate.

Design and Installation. The OSHA standard requires that machines and equipment be upgraded (rendered capable of being locked out), if necessary, when any major replacement, repair, renovation or modification is made. Managers and purchasing personnel should ensure not only that new equipment is "capable of being locked out," but also that ease of lockout is incorporated into the equipment's design. Many original equipment manufacturers offer lockout/tagout devices as accessories to their equipment and should be the first point of contact when purchasing lockout devices.

Review and Revision. OSHA requires that energy control procedures be reviewed at least annually to ensure that they are updated and accessible. If continuous improvement of the program is sought, updating of procedures should be done whenever deficiencies (or improvements) are identified. Training and retraining must also be conducted to ensure the continued proficiency of employees in following safe work practices.

Vital to program success is developing procedures that are understandable and easy for employees to implement. Building lockout capability into machines and having lockout materials and hardware readily available for use saves time and effort. Employees shouldn't be tempted to take shortcuts by having to walk a distance to obtain lockout devices. Successful best-management practices include placing lockout stations close to machines and equipment requiring frequent service or maintenance under lockout, or personally assigning locks, tags and appliances to authorized employees as is done with other types of personal protective equipment. It's also a good practice to post written energy control procedures at or near the machines to be serviced so they are accessible to employees. Clear plastic sheets will help protect the documents from damage.

Machine Guards Save Time

Locking out a machine each time a routine service or maintenance task, such as lubrication, cleaning, unjamming or adjusting, is performed is time consuming and adversely affects production. A key to maintaining or improving productivity is to eliminate maintenance task hazards by using machine guarding or other methods that provide effective protection. In this regard, OSHA advises that, as long as guarding is not removed or bypassed, the lockout/tagout standard is not intended to apply.

Consider the jamming of machines such as conveyors, packagers and labelers. Jams can occur frequently during production, requiring repetitive clearing. If employees are exposed to injury or must bypass safety guards to unjam the machine, it is considered "service or maintenance" under the OSHA standard, so lockout would be required each time the employee performs this function. Because the operating controls are generally not considered to be isolating devices, lockout is usually accomplished at the local disconnect or at the breaker (assuming electrical energy is the only type of energy encountered). To do this each time the machine jams is burdensome, time consuming and slows production. Consequently, a disincentive to follow lockout/tagout is established, and workers may feel pressure to take risks.

If guarding (or an alternative measure) is provided to effectively protect workers from hazardous parts of machinery during the unjamming operation, the task would be considered part of "normal production operations," so lockout would not be required. OSHA also advises that the standard does not apply if servicing is performed in a way that prevents employee exposure to unexpected activation of the machinery or equipment or to the release of stored energy, such as by the use of tools and alternative procedures that keep the employee's body out of the areas of potential contact with machine components or that otherwise maintain effective guarding. Thus, lockout is not required if it can be demonstrated that the alternative means enables the servicing employee to clean, unjam or otherwise service the machine without being exposed to hazards.

Similarly, the lubrication of power the transmission apparatus and other moving parts is a frequent and necessary maintenance task. If the apparatus is guarded (e.g., with a fixed, enclosure guard), the lubrication task will likely require removal of the guard to gain access. If employees are exposed to injury as a result, the equipment must be de-energized and locked out. Providing a small porthole in a guard or enclosure can often allow for the remote lubrication of equipment, making guard removal unnecessary. As long as the guarding adequately protects employees from injury, lockout would not be required. Look for opportunities to engineer hazards out of machines so safety and productivity can increase.

Performance Requirements

An effective lockout/tagout program will also establish specific performance requirements for controlling hazardous energy during the service or maintenance of machines, equipment and processes (MEP). These performance requirements should be spelled out in a written policy that defines responsibilities for carrying out the program and in "energy control procedures" (ECP), specific to each MEP. ECPs should describe the:

  • Machine, equipment or process to be locked/tagged out;
  • Intended use of the procedure or type of service/maintenance to be performed;
  • Types and magnitude of hazardous energy associated with the MEP;
  • Type and location of the isolating device(s);
  • Involved personnel;
  • Specific procedures and sequences for de-energizing, verifying and locking/tagging out the MEP; and
  • Specific steps for re-energizing the machine and restoring it to normal operation.

ECPs should be modified, as necessary, to reflect changes in the equipment, the method or location of isolation, the energy sources and involved employees.

Confirming the successful lockout of machines is critical to ensuring personnel protection. ECPs must include specific requirements for testing a machine or equipment to verify the effectiveness of lockout devices and other energy control measures. Prior to starting work on an MEP that's been locked/tagged out, an authorized employee must verify that isolation and de-energization of the MEP has been accomplished. The MEP must be checked by use of test instruments or visual inspection to verify that energy isolation has been accomplished. In addition to any needed visual or instrument testing, the equipment operating controls should be operated to verify that the equipment cannot be restarted. Operating control(s) should be returned to a safe condition (e.g., "neutral" or "off") before proceeding with service or maintenance.

With electrical energy, a qualified person should use test equipment to verify that all circuit elements and electrical parts of equipment to which employees could be exposed are de-energized. When appropriate, tests should be performed to determine if any energized condition exists as a result of an inadvertently induced voltage or backfeed. Such unexpected energization could occur even though specific parts of the circuit have been de-energized and presumed to be safe. Thus, additional precautions (e.g., grounding) may be necessary. Because most test instruments are battery-powered and batteries fail, it is important to check equipment for proper operation immediately before (and in the case of high voltage, immediately after) this check. Where there is a danger of injury due to accidental contact with energized parts or improper use of the test equipment, only qualified employees who have been trained in safe work practices should be permitted to perform the testing work.

With the pressure and stress of modern life, it's easy for workers to get careless. When working with industrial machinery, a moment of carelessness can easily result in a serious injury. The greatest benefit of a high performance lockout/tagout program is that, even if employees get careless, they'll be protected against injury.

Steve Kelley is a certified safety professional and certified hazardous materials manager with more than 14 years of EHS experience encompassing the insurance, transportation and manufacturing fields. He is a professional member of the American Society of Safety Engineers (Boston Chapter) and member of ASSE's Engineering and Environmental divisions. From 1988 to 1998, Kelley served as a member of the executive committee of the Massachusetts State Emergency Response Commission, playing an active role in emergency response and planning on the state level. He is employed as the senior environmental, health and safety engineer for Ionics Inc. in Watertown, Mass.

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