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.



March 16, 1993

Mr. Adonis Rowland
Fatality/Accident Investigator
Eugene Field Office
Oregon Occupational Safety and
Health Division
1140 Willagillespie Rd., Suite 42
Eugene, Oregon 97401

Dear Mr. Rowland:

This is in response to your February 18 letter requesting an interpretation of which Occupational Safety and Health Administration (OSHA) standards address the use of temporary vertical ladders known as "stack or scaling" ladders.

OSHA has divided all ladders into two groups: fixed and portable. By definition, stack and scaling ladders are portable ladders. The problem is that the specific provisions for portable ladders address fall protection concerns primarily by requiring the ladder to be used at a four to one angle (29 CFR 1926.1053(b)(5)(i) - note, the provision is also intended to address ladder stability issues). With regard to stack and scaling ladders used vertically, an alternative method of providing fall protection could be used (such as any of the methods or systems prescribed for fixed ladders) and the resulting violation of 1926.1053(b)(5)(i) would be considered to be "de minimis." A "de minimis" violation of a standard is one which has no direct or immediate relationship to employee safety or health. Of course, the ladder would have to be secured in a manner addressing the stability concerns.

If we can be of any further assistance, please contact [the Directorate of Construction at (202) 693-2020].


Roy F. Gurnham, Esq., P.E., Director
[Directorate of Construction]



February 18, 1993

Mr. Roy Gurnham
Director of Construction and
Maritime Compliance Assistance
Occupational Safety and Health
200 Constitution Ave. NW, Room N-3610
Washington, DC 20210

Mr. Gurnham,

I spoke with Mr. Dale Cavanaugh, Chief of Construction Compliance Assistance today by telephone.

As you may recall, I am investigating an industrial fatality involving a contractor who was performing chimney repair work. In addition to the information I have already requested from your office, I spoke with Mr. Cavanaugh about getting an interpretation on the use of temporary ladders which are evidently used by contractors on a frequent basis in this type of industry.

The ladders are frequently provided by the contractor, who is performing the work and installed in a vertical manner on the side of the chimney. After the work is completed the temporary ladder(s) are removed. The ladders stack on top of one another and are referred to as "stack or scaling ladders" by the industry. It is my understanding that these ladders would fall (no pun intended) under the fixed ladder standard.

Could you please send me an official interpretation?

Thank you very much for your assistance. If you have any questions please feel free to contact me.


Adonis Rowland
Fatality/Accident Investigator
Eugene Field Office
Oregon Occupational Safety &
Health Division
1140 Willagillespie Rd
Suite 42
Eugene, OR 97401
(503) 686-7562

[Corrected 05/28/2004]