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.

January 16, 2003

Mr. Michael J. Powers
Encompass Electrical Technologies-Florida
Business Region Safety & Training Director
430 West Drive
Altamonte Springs, Florida 32714

Re: Whether flexible cords/cables for temporarily powering equipment at a construction site may be run through holes in walls, floors, and ceilings; §1926.405(g)(1)(iii)(B)

Dear Mr. Powers:

This is in response to your letter dated April 23, 2002, to the Occupational Safety and Health Administration (OSHA). Your letter was forwarded to this office for handling on June 11, 2002. We apologize for the delay in responding.

We have paraphrased your question as follows:

Question: Section 1926.405(g)(1)(iii)(B) seems to prohibit flexible cords and cables from being run through walls, ceilings, or floors to power lights/power tools on a construction site. However, I note that in residential and commercial buildings, permanent wiring consisting of flexible cables (including type SER, NMB, MC, AC, telephone, TV, and thermostat cable) are commonly run through walls, floor, and ceilings. In order to light up a job site, power must be brought into every room, which necessitates running cables and cords through walls, etc.

Since these types of flexible cables are permitted to run through walls in permanent installations, is it permissible to run them through walls for temporarily powering lights/power tools?


In 29 CFR Part 1926 Subpart K (Electrical), §1926.405(g)(1) (Use of flexible cords and cables) states:

(i) Permitted uses. Flexible cords and cables shall be suitable for conditions of use and location. Flexible cords and cables shall be used only for:
(A) Pendants;
(B) Wiring of fixtures;
(C) Connection of portable lamps or appliances;
(D) Elevator cables;
(E) Wiring of cranes and hoists;
(F) Connection of stationary equipment to facilitate their frequent interchange;
(G) Prevention of the transmission of noise or vibration; or
(H) Appliances where the fastening means and mechanical connections are designed to permit removal for maintenance and repair. [Emphasis added.]

Section 1926.405(g)(1)(iii) (Prohibited uses) states:

Unless necessary for a use permitted in paragraph (g)(1)(i) of this section, flexible cords and cables shall not be used:
*            *           *
(B) Where run through holes in walls, ceilings, or floors;
*            *            *
(E) Where concealed behind building walls, ceilings, or floors. [Emphasis added.]

By its terms, the prohibition in §1926.405(g)(1)(iii) against running flexible cords and cables through holes in walls, ceilings, and floors does not apply where they are being used for one of the purposes listed in §1926.405(g)(1)(i). One such listed use is in (C), for connection of portable lamps. Therefore, under these sections, flexible cords and cables are permitted to be run through walls, ceilings, or floors when used to power portable lamps.

Another listed use in (C) is for connection of "appliances." In §1926.449, the standard defines appliances as:

utilization equipment, generally other than industrial, normally built in standardized sizes or types, which is installed or connected as a unit to perform one or more functions.

In general, portable construction power tools that are cord-and-plug connected, such as power hand drills, portable table saws, portable electric compressors for air-powered nailers, etc., meet the terms of this definition and so are "appliances" for purposes of this standard. Therefore, flexible cords/cables may be run through holes in walls, ceilings, or floors to power them.

Subpart K does not contain a definition of flexible cords and cables. In the absence of a definition in its standards, OSHA generally relies on the industry's understanding and use of a term at the time the standard was promulgated.

Subpart K was promulgated in 1986. At that time, the most current version of the National Electrical Code (NEC) was the 1984 version. It contains installation requirements regarding "flexible cords and cables" similar to those in the OSHA standard. The NEC requirements apply to flexible cords and cables listed in a table (see NEC Article 400.4). The NEC Article 400.4 Table does not list cords or cables with a designated use of telephone, TV or thermostats.
1 Therefore, neither the 1984 NEC nor the OSHA standard prohibits those from being run through walls, ceilings, or floors.

In addition, the Tables do not list SER, NMB, MC or AC
2 designated cable. We cannot comment on whether those would be permitted to be run through walls, ceilings, or floors without more detailed information regarding their capacities, and characteristics and use.

In sum, flexible power cords/cables used to power portable lamps and plug-in type portable construction power tools are permitted under Subpart K to be run through walls, ceilings, or floors (where necessary). Flexible cord/cables typically used in permanent installations for telephone, TV or thermostats are not prohibited from being run through holes in walls, ceilings, or floors by either the NEC or OSHA's Subpart K.

If you need any further clarification on this subject, please contact us by fax at: U.S. Department of Labor, Directorate of Construction Office of Construction Standards and Guidance. 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



1However, DP cable, for data processing is listed, although this was for 50 volts and higher. [back to text]





2 If by "AC" you were referring to cords used to power room air conditioners, those cords are included in the Table, under designation SP-3, SPE-3, and SPT-3, and are prohibited from running through walls, etc. under both the NEC code and the OSHA standard. unless used to power portable lamps or "appliances." [back to text]