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.

October 14, 1999

Mr. Dennis Vance
Safety Services
711 Low Gap Road
Princeton, WV 24740

Subject: 1926.404(b)(ii) and 1926.404(b)(iii); 1926.502(d)(15); 1926.502(d)(17); 1926.451(a); GFCI's; Cover Plates for Receptacle Boxes; Harness Attachment Points for Fall Arrest Equipment

Dear Mr. Vance:

This responds to your December 26, 1998, letter to the Occupational Safety and Health Administration (OSHA), in which you ask several questions regarding ground fault protection, fall protection and scaffolding. We apologize for the lateness of this response. We have paraphrased your questions as follows:

Requirement to use Ground Fault Circuit Interrupters when using extension cords plugged into permanent wiring

Question 1: You ask whether ground fault circuit interrupters (GFCIs) are required if the workers are standing on dry wood, vinyl tile and other flooring that does not have a ground path. You specifically reference an OSHA interpretation dated October 28, 1985, issued by John Miles, dealing with requirements for Ground Fault Circuit Interrupters (GFCIs), and ask if that memo continues to be in effect.

The 1985 memo dealt with 29 CFR 1926.400(h)(2). That provision has since been moved (without substantive change) and is now §1926.404(b)(1)(ii). It provides that:

All 120-volt, single-phase, 15- and 20-ampere receptacle outlets on construction sites, which are not a part of the permanent wiring of the building or structure and which are in use by employees, shall have approved ground-fault circuit interrupters for personnel protection...

The 1985 memo
The 1985 memo dealt with the issue of whether this provision required a GFCI if an extension cord were plugged into a permanent receptacle and powered equipment was, in turn, plugged into the extension cord. The memo stated that it had been OSHA's position that the end of the extension cord was a non-permanent "receptacle" and therefore needed a GFCI. It went on to explain, however, that due to "a recent [Occupational Safety and Health Review Commission] decision, OSHA could only require a GFCI in this circumstance where the exposed employee was in a location with a ready grounding path, such as damp or wet locations, outdoor areas, etc."

Current Policy
The 1985 memo was apparently referencing a decision by an administrative law judge, not the Review Commission; administrative law judge decisions do not have precedential effect. In fact, in 1995, the Review Commission clearly held in Otis Elevator Co., 17 BNA OSHC 1166 (No. 90-2046, 1995)
1 that the receptacle end of an extension cord is a non-permanent receptacle under this standard and that a GFCI is required unless the employer uses an assured grounding conductor program under 1926.404(b)(1)(iii). The application of the standard does not depend on the employee standing on a surface with a ready grounding path. Consequently, this letter rescinds and supersedes the 1985 memo.

Furthermore, it would be inappropriate to apply an across-the-board de minimis policy to these situations; in light of the ever-changing conditions typically encountered on construction sites, it would be unrealistic for us to assume that a ground path across or through the body is absent simply because the workers are standing on the surfaces you mention.

Cover plates are required on 120 volt receptacles.

Question 2: Does OSHA issue citations for 120 volt receptacles in use that do not have a cover plate on them?

Answer: Yes, a citation would be issued if a cover plate is missing from a receptacle box. There are a substantial number of electrocutions in this country that result from direct contact with 120 volt current, although we do not know the percentage of these attributable to missing cover plates.

The electric current commonly used on construction sites with 120 volt receptacles almost always carry more than enough amperage to cause electrocution. BLS recently published Report 934, "Fatal Workplace Injuries in 1997: A Collection of Data and Analysis." In 1997, there were a total of 297 fatalities. Forty-seven percent of fatal occupational injuries were caused by contact with electric current in construction. Additionally, 71 fatalities were due to contact with wiring, transformers, or other electrical components of which 46.5 percent were attributed to the construction industry.

Close tolerance receptacle boxes must also have covers

Question 3: If receptacle boxes are of close clearance which would make it almost impossible to accidently come in contact with the energized circuit, would this negate a citation?

Answer: No, cover plates are placed on boxes for reasons other than just preventing contact with an energized circuit. The use of a cover plate will keep sparks inside the box and reduce a fire hazard with any nearby combustible material.

Covers are required even if tape is used to cover power lugs and wires

Question 4: When installing the receptacles some electricians use electrical insulating tape around the power lugs and wires to prevent contact or short circuit. Would this negate a citation?

Answer: No, this additional step would not negate a citation for a missing cover plate. Some electricians do take the extra precaution and use electrical tape around the power lugs and wires prior to closing up the receptacle box but tape is not permitted as a cover substitute. The insulating properties of tape vary substantially depending on the type, condition and manner of installation of the tape.

Meaning of "attachment point of a harness" in a fall arrest system

Question 5: Does the statement in section 1926.502(d)(17), "attachment point of the harness" mean where the lanyard is attached to the employee or where the lanyard is attached to the anchor point?

Answer: The "attachment point" mentioned in the provision is the point where the lanyard attaches to the employee's harness. The attachment point is usually located in the center of the wearers's back near shoulder level.

When scaffolds may be used to anchor fall arrest systems; effect of a manufacturer's warnings not to use its scaffolds as anchor points

Question 6: You have submitted letters from some equipment manufacturers that state that it is unsafe to anchor fall arrest equipment to their scaffold systems. You also referenced a letter dated April 2, 1998, that this office sent to Mr. John Palmer which you believe contradicts the advice of these manufacturers.

Answer: OSHA's letter to Mr. Palmer states that while the typical erected scaffold may not withstand the forces imposed by an arrested fall, with proper engineering, a scaffold can be designed so that its components are adequately braced or supported to support such loads. However, a scaffold should never be used as an anchorage point for a fall arrest system unless it has been properly evaluated by a competent person.

Where the manufacturer states that no part of the scaffold is to be used to anchor a fall arrest system, the scaffold may only be used to anchor a fall arrest system if a competent person is able to correctly determine that it can be so used. Section 1926.450(a) defines a competent person as "one who is capable of identifying existing and predictable hazards in the surroundings or working conditions which are unsanitary, hazardous, or dangerous to employees, and who has authorization to take prompt corrective measures to eliminate them." The preamble to the standard further defines the training of the competent person (bottom of the right paragraph on page 46,059 of Volume 61 of the Federal Register) by stating:

For example, a 'competent person' for the purposes of this provision must have had specific training in and be knowledgeable about the structural integrity of scaffolds and the degree of maintenance needed to maintain them. The competent person must also be able to evaluate the effects of occurrences such as a dropped load, or a truck backing into a support leg that could damage a scaffold. In addition, the competent person must be knowledgeable about the requirements of this standard. A competent person must have training or knowledge in these areas in order to identify and correct hazards encountered in scaffold work.



The competent person must be able to carry out the tasks specified in the standard. For example, to be able to carry out the tasks required in §1926.451(f)(3) — inspecting for visual defects and structural integrity — the competent person needs to have knowledge in the issues relating to the strength and structural integrity of the scaffold. In many cases the competent person will use a manufacturer's guidelines in carrying out these duties.

Manufacturers normally use engineering calculations, testing results and other considerations in preparing their guidelines on procedures and limitations. OSHA's scaffold standard itself does not mandate compliance with such guidelines. However, to deviate from them and still meet the requirements of a competent person, that person would need to have a very high level of knowledge — a level that would enable him or her to understand the concerns the guidelines are meant to address and to determine that the deviation would not result in a hazardous condition. Mere "experience" that the scaffold had previously been used in a way that deviates from the guidelines with no apparent failure is not a basis on which a competent person (or an employer) could proceed; such "experience" could be purely a product of luck.

In the situation you have described, the competent person must be able to assess whether the scaffold will withstand the loads imposed by an arrested fall. While an engineering degree is not a prerequisite, that assessment normally requires some engineering skills, and the competent person making that determination would have to have those skills. If that person lacked those skills and deviated from the manufacturer's guidelines, a citation under the relevant provision of the standard, such as §1926.450(f)(3) (inspection by a competent person) or 1926.450(f)(7) (competent person must supervise and direct the erecting, moving and dismantling of scaffolds), would be appropriate.

Alternatively, the employer can comply by using a "qualified person" to make this assessment. A qualified person is "one who, by possession of a recognized degree, certificate, or professional standing, or who by extensive knowledge, training, and experience, has successfully demonstrated his/her ability to solve or resolve problems related to the subject matter, the work, or the project."

If you need additional information, please contact us by fax at: U.S. Department of Labor, OSHA, Directorate of Construction, Office of Construction Standards and Guidance, fax # 202-693-1689. You can also contact us by mail at the above office, Room N3468, 200 Constitution Avenue, N.W., Washington, D.C. 20210, although there will be a delay in our receiving correspondence by mail.


Russell B. Swanson, Director
Directorate of Construction

[Corrected 6/2/2005]



1 [A copy of this decision is available at www.oshrc.gov; click on "Decisions" and then under "Final Commission Decisions;" click on "1995" and scroll down to the entry "Otis Elevator Company, docket number 90-2046 final order date 04/04/95"] [ back to text ]