LOCKOUT is a more effective means of ensuring the de-energization of equipment; it is the preferred method because lockout-based safety programs are less susceptible to human error, and tagout devices have INHERENT PHYSICAL LIMITATIONS. Therefore, if the energy isolating device is capable of being locked out, the standard requires LOCKOUT unless the employer can demonstrate that a tagout system will provide Full Employee Protection (“Tags Plus”) — i.e., a level of protection that is equivalent to that provided by the lockout.
For a facility to demonstrate that a TAGOUT program is as protective as a lockout program for a lockable piece of equipment or machine, it must show additional elements that bridge the gap between lockout and tagout. It is permissible for employers to implement a tagout program provided that ALL APPLICABLE full employee protection requirements are met.
The term “Full Employee Protection” is outlined in 1910.147(c)(3), and it REQUIRES compliance with ALL tagout-related provisions of the standard, which includes attaching the tagout device at the same location that the lockout device would have been attached to. Also, inherent tagout program limitations necessitate implementing additional program and specification requirements when an employer opts to use a tagout program instead of a lockout program.
A key element in demonstrating that the tagout program provides equivalent protection to a lockout program is the standard’s provision that the tagout program provides AT LEAST ONE ADDITIONAL SAFETY MEASURE. In other words, at least one added safety measure MUST be used in addition to tagging the energy isolation device to prevent unexpected re-energization. This independent, additional measure is designed to protect an employee from injury or death through the inadvertent activation of an energy-isolating device associated with human error, inadvertent contact, the loss or detachment of a tag, or from any other limitation of tags.
Such additional safety measures might include the:
- Closure of a second-in-line valve (e.g., double block and bleed);
- Removal of a valve handle to minimize the possibility that machines or equipment might be inadvertently energized or started;
- Removal of an additional isolating circuit element (e.g., fuse);
- Opening of an extra disconnecting device (e.g., disconnecting switch, circuit breaker);
- Opening and then racking out a circuit breaker;
- Grounding of an electrical circuit, if the grounding practice would protect the employee if the tagged isolating device were operated; or
- Locking, blocking, or barricading a controlling switch.
Any additional control measure (e.g., “Tags Plus”) MUST be integrated into an energy control program through SOUND HAZARD-SPECIFIC ANALYSES ON A CASE-BY-CASE BASIS. For example, the blocking of a control switch as an additional measure to tagging an electrical disconnect may be an effective second layer of protection for preventing the mechanical activation of a machine. Still, this block may be an inadequate “Tags Plus” measure for the same machine’s hydraulic or pneumatic hazardous energy sources. When effectively incorporated into the employer’s energy control program and enforced through regular supervision, these independent control measures provide employees with an independent, redundant control measure. In short, this additional control measure provides the authorized employee using a tagout program with a “second layer of protection” if the tagout device for the primary isolating device is defeated.
IMPORTANT NOTE regarding ANSI/ASSE Z244.1-2003: While describing additional protective means similar to those listed in §1910.147(c)(3)(ii), the American National Standard on the Control of Hazardous Energy – Lockout/Tagout And Alternative Methods (ANSI/ASSE Z244.1-2003; Section 5.3.1) requires the user to demonstrate that the TO program provides an effective level of safety whereas paragraph (c)(3) requires the employer to demonstrate that the tagout program will provide a level of safety equivalent to that obtained by using a lockout program.