Verification of group lockout and tagout across shifts

January 29, 2002

Mr. Jack Prestwood

Tampa Electric Company

Polk Power Station

[Recipient address omitted]

Dear Mr. Prestwood:

Thank you for your June 8, 2001 facsimile to the Occupational Safety and Health Administrations's (OSHA's) Directorate of Compliance Programs (DCP). This letter constitutes OSHA's interpretation only of the requirements discussed and may not be applicable to any scenario- not delineated within your original correspondence. You had specific questions regarding the Electric Power Generation, Transmission, and Distribution, §1910.269, standard. Please accept our apology for the delay in responding.

You are seeking clarification with respect to the group lockout/tagout requirements [§1910.269(d)] and a November 16, 1999 interpretation letter (copy attached) to Environmental, Management, and Training Systems, Inc. This interpretation letter describes a turnaround scenario involving many workers and multiple energy isolating devices that are locked- or tagged-out (LOTO). The letter explains that, generally, each authorized employee, or alternatively, the primary authorized employee, must verify isolation of hazardous energy sources prior to the start of work on each shift. Your question and our reply follow:

Question: If a primary authorized employee verifies the lockout/tagout at the beginning of a job that will last an extended amount of time, must this employee walk down the lockout/tagout every day? In addition, Tampa Electric Company uses a tagout system; would the reply to question #4 (of the EMTS, Inc. letter regarding lockout) apply to tagout as well?

Reply: The reply to question #4 of the EMTS, Inc. letter provides that when an authorized employee(s) remains signed on to the LOTO [i.e., his or her lock(s) has remained continuously attached to the appropriate master lock mechanism over a number of shifts and since he or she verified that the hazardous energy was effectively isolated], the verification of isolation is not necessary for each of these shifts.[1] The same interpretation applies to tagout devices when they are permitted and when they are used in accordance with all of the tagout-related provisions of §§1910.147 and 1910.269(d). However, because a tagout program does not involve positive restraints on energy control devices, it requires additional vigilance to ensure that:

tagout devices are properly applied;

they remain affixed throughout the servicing and maintenance period; and

no employee violates the tagout device by re-energizing the machine or equipment, either intentionally or inadvertently, before the tagout device(s) is removed.[2]

Furthermore, it is extremely important to note that when there exists a possibility for re-accumulation of stored energy (e.g., fluid leakage from pipes, valves or other containment systems) to a hazardous level, both §§1910.147(d)(5)(ii) and 1910.269(d)(6)(vi) require continued verification of isolation until the servicing or maintenance is complete. This requirement applies regardless of whether or how long a lockout- or tagout-device is used by an employee(s) across shifts.

Thank you for your interest in occupational safety and health. We hope you find this information helpful. OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at http://www.osha.gov. If you have any further questions, please feel free to contact the Office of General Industry Compliance Assistance at (202) 693-1850.

Sincerely,

Richard E. Fairfax, Director

Directorate of Compliance Programs

Enclosure

[1] While hazardous energy isolation may be accomplished by a single authorized employee (a "primary authorized employee") in a group lockout/tagout scenario, each authorized employee has the right, and must be given the opportunity, to participate in the verification process, regardless of whether the verification ultimately is performed by each authorized employee or by a primary authorized employee [Back to text]

[2] OSHA has determined that lockout is a surer means of assuring de-energization of machines and equipment than tagout. Lockout must be used when energy isolating devices are capable of being locked out, unless the tagout program can be shown to provide a level of safety equivalent to that obtained by using a lockout program. See §1910.147(c)(3) on "Full employee protection." [Back to text]