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• Standard Number: 1926.351(c)(6); 1926.453(b)(2)(xi); 1926.453(b)(2)(v); 1926.453(b)(2)(iii); 1926.453(b)(2)(vi)

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

February 23, 2004

John N. Poulmentis
285 E. Montank Highway
P.O. Box 662
Hampton Bays, New York 11946

Re: Under OSHA's construction standards, is it permissible for welding leads to be attached to an occupied aerial lift bucket? Is it permissible for a vertical lifeline to be used to anchor fall arrest equipment used while working inside the bucket?

Dear Mr. Poulmentis:

This is in response to your November 5, 2003, letter to the Occupational Safety and Health Administration (OSHA), in which you ask several questions about working in the bucket of an aerial lift.

We have paraphrased your questions as follows:

Question (1): Scenario: Two workers are going to do welding work while in an aerial lift bucket. Are there any OSHA standards that prohibit them from attaching the welding equipment leads to the bucket?

Although there is no specific standard prohibiting the attachment of the welding leads to the bucket, §1926.351(c)(6) requires that:
All ground connections shall be inspected to ensure that they are mechanically strong and electrically adequate for the required current.
Section 1926.453(b)(2)(xi) states:
The insulated portion of an aerial lift shall not be altered in any manner that might reduce its insulating value.
Therefore, it would be a violation of §1926.453(b)(2)(xi) if, in order to attain the "mechanically strong and electrically adequate" ground connection required in §1926.351(c)(6), an insulated portion of the aerial lift was damaged. Also, failure to attain such a ground would be a violation of §1926.351(c)(6).

We have insufficient information to comment on whether connecting the leads to the bucket could cause damage to the aerial lift or pose an electrical hazard to other workers.

Question (2): Scenario: Two workers from another company working in an aerial lift are installing cellular communication antenna mounts on a water tank. There is a vertical lifeline that runs from the ground up to a point on the tank next to the bucket (it is attached to the tank, not the aerial lift). Our employee, who will be observing the work, uses the vertical lifeline to anchor fall protection equipment (a full-body harness, lanyard, a damper and rope-grab) while climbing up to and into the aerial lift bucket. The observer is tied off 100% of the time, is not connected to the bucket once within it, and will always be supported by the vertical lifeline should the aerial lift fail. The anchor point for the vertical lifeline, including the tank itself, will withstand a 5,000-pound arresting force. The maximum load of the aerial lift basket is 500 lbs.

Does the use of the fall protection system described above comply with OSHA fall protection standards?

Section 1926.453(b)(2)(v) of the aerial lift standard requires that:
A body belt shall be worn and a lanyard attached to the boom or basket when working from an aerial lift.
Section 1926.453(b)(2)(iii) also states:
Belting off to an adjacent pole, structure, or equipment while working from an aerial lift shall not be permitted.
In the scenario you describe, the observer from your company, while in the bucket also, is anchored to an external vertical life line that is secured to a water tank. Securing the observer to an adjacent structure is in violation of §1926.453(b)(2)(iii). However, in the scenario you describe the violation of §1926.453(b)(2)(iii) would be considered de minimis.

In a February 2, 2004, letter to Mr. Kurtgis, we noted that this prohibition addresses, among others, the hazard of such an adjacent pole/structure failing and pulling the attached worker from a bucket. This may occur where, for example, a utility pole has rotted and fails while work is done to equipment attached to it, or where a traffic accident occurs in which a vehicle strikes the pole.

The provision reflects a concern that the type of "adjacent" structures typically associated with work done from aerial lifts are unreliable with respect to their condition (and so their ability to withstand loads imposed on them while work is being done) and vulnerability to traffic accidents. However, as we stated in the Kurtgis letter:
[L]imited situations may exist where an adjacent structure poses no reasonably foreseeable risk of failure. For example, such an instance might arise where the adjacent structure is a completed building or a completed (i.e., fully bolted-up) skeletal steel structure. In those instances, OSHA would consider the violation of §1926.453(b)(2)(iii) to be "de minimis" and no citation would be issued.
The water tank that you describe in your letter would also be considered a structure that poses no reasonably foreseeable risk of failure. Therefore, we would consider the violation of §1926.453(b)(2)(iii) to be de minimis.

Not having the observer attached to the boom or basket is a violation of §1926.453(b)(2)(v). However, since the worker is tied-off to the vertical lifeline, and as discussed above that tie-off is acceptable, the failure to tie off to the boom or bucket is only a de minimis violation (i.e., no citation would be issued). Tying off to the vertical lifeline, which is attached to the tank, would prevent the worker from falling in the event the worker were bounced out of the bucket or were the aerial lift to fail or fall.

Finally, we note that you included in your scenario the fact that the bucket's maximum load is 500 pounds. We cannot determine from the information submitted if the total weight of the two workers, your observer, the welding equipment, and any other equipment that may be in the bucket would exceed that load capacity. Section 1926.453(b)(2)(vi) states:
Boom and basket load limits specified by the manufacturer shall not be exceeded.
You must ensure that, once the observer enters the aerial lift bucket with the two other workers, this requirement is not violated.

If you need additional information, please contact us by fax at [202-693-1689]: U.S. Department of Labor, OSHA, 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

1 Under OSHA's de minimis policy, de minimis violations are those which have no direct or immediate relationship to safety or health. [
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