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 https://www.osha.gov.

April 3, 2012

Mr. Richard F. Kayser
Chief Safety Officer
United States Department of Commerce
National Institute of Standards and Technology
Gaithersburg, Maryland 20899

Dear Mr. Kayser:

Thank you for your letter to the Office of Federal Agency Programs. You requested clarification regarding the interpretations of "under the exclusive control of the employee" and "authorized employee" as they pertain to The Control of Hazardous Energy (Lockout/Tagout) standard, 29 CFR 1910.147. This letter constitutes OSHA's interpretation only of the requirements herein, and may not be applicable to any question not delineated within your original correspondence. Your paraphrased questions and our responses are listed below.

Note: You referred to a previous letter of interpretation (August 24, 2005), Previous Letter that addressed drill press tool changes for milling machines in a private sector industrial setting. Our responses to your questions address your described federal agency laboratory setting and cord and plug equipment.

Scenario: Various personnel maintain equipment, devices, and fixtures in a government-operated laboratory setting. Some of these activities may include the following:

  1. Maintenance tasks involving the isolation of energy sources of electrical energy for equipment.
  2. Maintenance tasks requiring isolation of power to devices or fixtures prior to work.

Question 1: Is the employee performing servicing or maintenance on cord and plug connected electric equipment under the §1910.147(a)(2)(iii)(A) standard exception required to be an "authorized employee" per the §1910.147 standard?

Reply 1: No. As long the method of isolating the energy to the equipment is limited to unplugging the equipment and maintaining control of the plug, §1910.147 does not require an employee who performs maintenance on cord and plug connected equipment to be an "authorized employee."

Question 2: Does the use of the term "authorized employee" in Footnote 5 of the August 24, 2005 letter of interpretation refer to an authorized employee per §1910.147(b) or simply to employees empowered, commissioned, or enabled by their employer to perform cord and plug equipment servicing or maintenance?

Reply: The term authorized employee in Footnote 5 refers to an authorized employee as defined in §1910.147(b).

Question 3: Wouldn't the two standard exceptions detailed in §1910.147(a)(2)(iii) (cord and plug electrical equipment and hot tap) be excluded from the entire control of hazardous energy standard, including those sections pertaining to authorized employees, when the respective exceptions are met?

Reply: Yes. According to paragraph §1910.147(a)(2)(iii)(A), the standard does not apply to [w]ork on cord and plug connected electric equipment for which exposure to the hazards of unexpected energization or start up of the equipment is controlled by the unplugging of the equipment from the energy source and by the plug being under the exclusive control of the employee performing the servicing or maintenance. And, while your scenario did not address hot tap operations, paragraph §1910.147(a)(2)(iii)(B) specifies the criteria for excepting such activitites.

However, please be aware that exclusion from a particular standard does not exempt an employer from complying with other applicable standards. For example, §1960.8(a), Basic Program Elements for Federal Employees OSHA (Agency Responsibilities), obligates federal agencies to provide places of employment that are free from recognized hazards that are causing or are likely to cause death or serious physical harm. Therefore, during your maintenance operations, if a hazard exists and there is employee exposure to the same, the agency must minimize or eliminate exposure to the hazard.

Question 4: Would the authorized employee training requirements specified in §1910.147(c)(7)(i)(A) be required for an employee performing servicing or maintenance activities under the §1910.147(a)(2)(iii)(A) exception?

Reply: No. The training requirements described in §1910.147(c)(7)(i)(A) do not apply to maintenance activities involving cord and plug equipment or hot tap operations. However, please be aware that the exemption for cord and plug equipment is based solely on the equipment, not the setting. For example, if a worksite contains both cord and plug equipment and other equipment with sources of energy that must be isolated through the use of locks, tags, or similar devices, the exemption applies only to the cord and plug equipment, not all the equipment at the site.

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 Federal Agency Programs at 202-693-2122.

Sincerely,

Thomas Galassi, Director
Directorate of Enforcement Programs