February 3, 2010
Thank you for your February 11, 2008, correspondence to OSHA's Directorate of Enforcement Programs (DEP). You had questions regarding OSHA's standard on Electric Power Generation, Transmission, and Distribution (29 CFR §1910.269). Your paraphrased scenarios and questions and our replies follow. This letter constitutes OSHA's interpretation only of the requirements discussed and may not be applicable to any questions not delineated within your original correspondence.
Scenario 1: A qualified employee is working alone to connect a service at the 120-volt secondary bushing of an energized pole-mounted transformer1 . The transformer has a single, high-side (primary), 7,200-volt bushing that is located 18 inches from the secondary bushing. The employee is working from an insulated aerial lift bucket and working within the minimum approach distance of the primary (2 feet, 1 inch for live-line work2 ). There is no phase to phase exposure and the employee cannot reach or fall into the high-side bushing from his or her work position. The employee would keep his face, chest, and other uninsulated body parts at least 2 feet, 1 inch away from the parts that are energized at 7,200 volts. The employee is wearing Class 2 insulating gloves and sleeves for the primary voltage of 7,200 volts.
Question 1: Could a qualified employee work alone on a part energized at less than 600 volts in this scenario, or is a two-person crew required?
Response 1: 29 CFR 1910.269(1)(1)(i) provides that at least two employees must be present when the following types of work are performed:
- Installation, removal, repair of lines that are energized at more than 600 volts;
- Installation, removal, or repair of deenergized lines if an employee is exposed to contact with other parts energized at more than 600 volts;
- Installation, removal, or repair of equipment, such as transformers, capacitors, and regulators, if an employee is exposed to contact with parts energized at more than 600 volts;
- Work involving the use of mechanical equipment, other than insulated aerial lifts, near parts energized at more than 600 volts; and
- Other work that exposes an employee to electrical hazards greater than or equal to those posed by operations that are specifically listed in paragraphs (I) (1) (i)(A) through (1) (l)(i)(D) of this section.3
For purposes of this paragraph, OSHA has defined "exposed to contact" to mean any situation in which an employee is in a working position from which he or she can reach or take a conductive object within the electrical component of the applicable minimum approach distance. (See Section III of Appendix B to 1910.269 for additional information about the electrical components of the minimum approach distances for different voltages.) An employee who is "exposed to contact" with an energized part under this definition is still "exposed to contact" with the energized part even if insulation covers the part, the employee or both. See §1910.269(x) (defining "exposed" as not isolated or guarded; merely covering a conductor or an employee with insulation does not provide guarding or isolation).
Although paragraph (l)(l)(i)(C) is potentially applicable to your scenario, the employee working on the secondary bushing of the transformer from the position described in your letter is not "exposed to contact" with the primary bushing as long as he or she cannot reach or take a conductive object into the electrical component of the minimum approach distance of that bushing. Please note, however, that a second employee may still be required if the employee can reach or take a conductive object into the electrical component of the minimum approach distance when he or she is approaching or leaving his or her final work position or moving from one work position to another.
Scenario 2: Under the same conditions as Scenario 1, the employee has applied appropriately rated insulating material by hot stick to the primary energized parts.
Question 2: In this scenario, can a qualified employee work alone on a part energized at less than 600 volts; or is a two-person crew required?
Response 2: As stated in response to question 1, the presence of insulation on the energized part has no bearing on whether the employee is "exposed to contact" for purposes of paragraph (l)(l)(i). Therefore, the response to this question is the same as the response to question 1.
Question 3: Would Class 2 gloves and sleeves be required to work on the secondary bushing after the primary has been covered up, or could the employee wear gloves rated for the voltage being worked on (Class 0)?
Response 3: Paragraph (l)(2) of §1910.269 requires the employee to maintain the minimum approach distance from exposed energized parts unless the employee is insulated from the energized part (paragraph (1)(2)(i)), the energized part is insulated from the employee (paragraph (1)(2)(ii)), or the employee is insulated from any other exposed conductive object, e. g., live-line bare-hand work (paragraph (1) (2) (iii)). Thus, if the primary is insulated by cover-up sufficient for the maximum use voltage, as required by §1910.137(b)(2)(i), then, that would constitute compliance with §1910.269(1)(2)(ii) with respect to the primary. Consequently, gloves could be Class 0, which would be sufficient to protect the employee from the secondary voltage of 120 volts, single phase and would comply with §1910.269(1)(2)(i) with respect to the secondary4.
Question 4: What is the relationship between the phrase "exposed to contact" in 1910.269(1)(1)(i) and the minimum approach distances found elsewhere in section 1910.269?
Response 4: As stated in response to question 1, OSHA has defined "exposed to contact" to mean any situation in which an employee is in a working position from which he or she can -reach or take a conductive object within the electrical component of the minimum approach distance.
Question 5: For purposes of 1910.269(1)(1)(i), is an employee "exposed to contact" with parts energized at more than 600 volts if he or she is working on 600 volts or below, is insulated for the highest voltage with gloves and sleeves, and cannot reach voltages that exceed 600 volts?
Response 5: For the reasons given in response to question 1, the employee in this scenario is not "exposed to contact" with parts energized at more than 600 volts as long as he or she cannot reach or take a conductive object into the electrical component of the minimum approach distance for those parts. As stated above, however, a second employee might still be required if the employee can reach or take a conductive object into the electrical component of the minimum approach distance of the 7,200-volt energized parts when he or she is approaching or leaving his or her final work position or moving from one work position to another.
Question 6: 29 CFR §1910.269(l)(1)(ii)(C) permits an employee to work alone to perform "[e]mergency repairs to the extent necessary to safeguard the general public." What is deemed an emergency that would require or permit a utility company to allow a single employee to work on primary voltage to the extent necessary to safeguard the public?
Response 6: It is impossible to definitively list all situations that would qualify as emergency repairs necessary to safeguard the general public. OSHA would generally consider situations where there is a downed energized power line, an energized power line on an occupied vehicle, or a service outage to life support equipment to be emergency situations for which an employee could work alone to safeguard the public. Whether outages to street lights, traffic lights or homes, will be considered emergency situations for purposes of paragraph (l)(1)(ii)(C) depends on many factors, including the extent and expected duration of the outage and the availability of alternative means of protecting the public, e.g., the availability of police or other officials to manage or stop traffic. at-intersections in-the absence of working stoplights. Because hospitals and similar patient care facilities usually have backup generators, outages to their service are not, alone, generally deemed to fall under paragraph (l)(1)(ii)(C).
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 Enforcement at (202) 693-1850.
Richard E. Fairfax, Director
Directorate of Enforcement Programs
1 The repair or direct replacement of an existing electric service would constitute a maintenance activity covered by 29 CFR 1910.269. The installation of new service, however, would constitute construction work, as defined in 29 CFR §1910.12(d), if the work "includes the erection of new electrical transmission and distribution lines and equipment... [or] the alteration, conversion, ... [or] improvement of ... existing transmission and distribution lines and equipment." This type of work would be covered by the standards for the construction of electrical power transmission and distribution installations found in 29 CFR 1926, Subpart V. Questions about construction work should be directed to the Directorate of Construction by fax (202-693-1689) or at: U.S. Department of Labor, OSHA, Office of Construction Standards and Guidance, Room N3468, 200 Constitution Avenue, N.W., Washington, D.C. 20210. [Return to Text]
2 The a-c live-line minimum approach distance for phase-to-ground exposure according to 29 CFR 1910.269, Table R-6 is 0.64 meters (2 feet, 1-inch). An altitude correction factor as included in 29 CFR 1910.269, Table R-10 might apply if the work is performed at greater than 900 meters (3,000 feet). [Return to Text]
3 In the §1910.269 rulemaking, OSHA determined that there was a need to have an extra employee present for these operations. The preamble to the final standard explained that in the event of an electric shock incident, the two person requirement provides "the immediate availability of a person trained in CPR [cardiopulmonary resuscitation]." The Agency also noted that an additional employee, "should be able to point out poor work practices to their fellow employees." (59 FR 4380, Jan. 31,1994) [Return to Text]
4 At this voltage, OSHA will consider it a de minimis violation to use Class 00 Rubber Insulating Gloves which meet the 2009 ASTM Dl20 standards. [Return to Text]