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 7, 1999

Mr. Michael T. Williams
Vertical Access Systems & Technology
2428 Whetstone Court
Salem, Oregon 97304

Dear Mr. Williams:

This is in response to your letter of February 19, 1997. Please pardon our delay in response. You asked two questions regarding descent control in general industry work other than window cleaning. Your questions and our responses are as follows:

Question 1. Would OSHA allow the use of descent control devices by workers on bridges, transmission and distribution towers, telecommunication towers, or buildings if the eight points mentioned in the
March 12, 1991 memorandum to Regional Administrators from Patricia K. Clark was followed?

Answer: OSHA's response is affirmative. The eight points describe procedures and precautions that employers are expected to use in any situation in which employees use descent control devices. Please note the further provision that the equipment should be used in accordance with the instructions, warnings and design limitations set by manufacturers or distributors.

Question 2. Would Patricia Clark's clarification to Mr. Bell dated July 31, 1991 concerning provisions for stabilization also apply in these other occupations, bridges, towers, etc., where she stated a device as simple as a suction cup could be used if there was proper training in its use?

Answer: OSHA's response is again affirmative. This provision is intended to be used in combination with the other seven points as referenced in the March 12 memorandum discussed above. I hope these responses address your concerns. If you have any further questions, you may call [the Office of General Industry Enforcement at 202 693-1850].



Richard Fairfax, Director
[Directorate of Enforcement Programs]

[Corrected 10/22/2004]

July 31, 1991

Mr. Michael Bell
Descent Control Inc.
Warrington, Pennsylvania 18976

Dear Mr. Bell:

This is in response to your July 15 inquiry requesting a clarification of a section of the
March 12, 1991 memorandum to all Regional Administrators of the Occupational Safety and Health Administration (OSHA) concerning the use of descent control equipment by employees performing building exterior cleaning, inspection and maintenance.

I understand that you have already spoken to someone in OSHA on this subject, but that you need written confirmation for one or more of your clients.

I hope the following information will be of help to you:

The question at issue is the meaning of item number 8 on the second page of the above mentioned memorandum. (copy enclosed).

The intent of this is to ensure that employees are furnished with a device or devices to provide intermediate stabilization for descents in excess of 130 feet (stabilization at the specific work location, i.e. window). A device could be something as simple as a acceptable suction cup attached to the worker's seat board by a short lanyard.

Item number one on page one of the memorandum would require that the worker be properly and effectively trained in the use and application of such stabilization devices.

I trust that the above will satisfy your needs, but if further assistance is required, please do not hesitate to contact my office again.



Patricia K. Clark, Director
[Directorate of Enforcement Programs]

March 12, 1991

SUBJECT: December 5, 1989 letter from Mr. Thomas J. Shepich to Mr. Carl A. Pedersen regarding Descent Control Devices

The purpose of the memorandum is to clarify statements made in the above-referenced letter (attached) regarding the use of descent control equipment by employees performing building exterior cleaning, inspection and maintenance. Descent control equipment (friction devices such as "Sky Genies", "racks" and "figure eights") is not covered by existing Occupational Safety and Health Administration (OSHA) standards. Therefore, the Agency addresses the safety of descent control devices through its enforcement of section 5(a)(1) of the OSH Act. Under this approach, OSHA references the safety principles applicable to similar equipment (in this case, boatswains' chairs, single-point and two-point suspended scaffolds) and national consensus standards (such as ANSI A39.1-1987, with addenda A through C, "Safety Requirements for Window Cleaning") insofar as they are pertinent to the subject matter.

As indicated in the December 5, 1989 letter, OSHA allows employees to use descent control equipment, provided that the equipment is used in accordance with the instructions, warnings and design limitations set by manufacturers or distributors. In addition, the Agency expects employers whose employees use descent control devices to implement procedures and precautions, as follows:

  1. Training of employees in the use of the equipment before it is used;
  2. Inspection of equipment each day before use;
  3. Proper rigging, including sound anchorages and tiebacks, in all cases, with particular emphasis on providing tiebacks when counterweights, cornice hooks, or similar non-permanent anchorage systems are used;
  4. Use of a separate fall arrest system (including bodybelt, sit harness, or full body harness; rope grab or similar device; lifeline; and anchorage (all of which are completely independent of the friction device and its support system)), so that any failure in a friction device, support seat (or harness), support line, or anchorage system will not affect the ability of the fall arrest system to operate and quickly stop the employee's fall;
  5. All lines installed (such as by using knots, swages or eye splices) when rigging descent control devices shall be capable of sustaining a minimum tensile load of 5,000 pounds.
  6. Provisions are made for rescue;
  7. Ropes are effectively padded where they contact edges of the building, anchorage, obstructions, or other surfaces which might cut or weaken the rope;
  8. Provisions are made for intermittent stabilization for descent in excess of 130 feet.

In accordance with ANSI A39.1-1987 (and addenda a-c), emergency descent devices are prohibited for use in window cleaning. That statement pertains to devices designed only for emergency use. The statement would not preclude the use of descent control equipment designed to be used for window cleaning, nor would it preclude the use of devices that are designed for both window cleaning and emergency descent, provided these devices are used in accordance with the guidance outlined in this memorandum.