September 30, 2002

Mr. Barry Jackson
Structural Engineer
National Dynamics Corporation
PO Box 80404
Lincoln, NE 68501

Dear Mr. Jackson:

Thank you for your May 22, 2002 letter to the Occupational Safety and Health Administration's (OSHA's), Directorate of Enforcement Programs (DEP). This letter constitutes OSHA's interpretation only of the requirements discussed and may not be applicable to any question not delineated within your original correspondence. You had specific questions regarding whether steel stacks are considered chimneys within the context of the fixed ladder standard.

Scenario: Our client's company provides landing platforms for each 30 feet of stack height. In order to lower manufacturing costs the client would like to allow the use of a continuous climb fixed ladder with safety climbing devices instead of ladder cages and platforms.

Question: Are steel stacks considered chimneys under §1910.27(d)(2)?

Reply: Yes. Based on a previous letter of interpretation to Mr. Gene Follstaedt dated July 23, 1998 (enclosed), steel stacks are considered chimneys.

Question: Can the word "chimney" as used in §1910.27(d)(5) be substituted with "stack"?

Reply: Yes. However, your client should be aware of other considerations when deciding to use continuous climb ladders provided with fall protection, such as ladder safety devices as mentioned in the standard. These considerations include, but are not limited to:

• Any local, state, or other regulation which may prohibit or limit their use;
• Manufacturing standards which may require platforms for access to controls or inspection points;
• Frequent inspection and maintenance requirements if installed in or near corrosive or other extreme environments which could affect structural integrity;
• Climber safety where installed in areas with high winds, extreme temperatures, or other hazardous environments;
• Climber's age and physical condition;
• Ease of use (encourages compliance);
• Requirements for fall arrest and positioning equipment (including training on its use and application); and
• Availability of rescue personnel, ladders, or other rescue equipment in case the climber cannot self-rescue.

If your client prefers platforms to ladder safety devices, you are aware that the current OSHA standard, 1910.27(d)(2), has a 30-foot limit between platforms; however, the proposed 29 CFR Part 1910, Subpart D (published April 10, 1990) extends the distance of continuous climb on a ladder with a cage or well to a length not to exceed 50 feet (proposed 1910.23(c)(16), 55 FR 13399, enclosed). Where the level of safety is not diminished, compliance with the proposed standard, which references the consensus standard ANSI A14.3-1984, would be acceptable.

Thank you for your interest in occupational safety and health. We hope you find this information helpful. 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. If you have any further questions, please feel free to contact the Directorate of Enforcement Programs at (202) 693-2100.

Sincerely,



Richard E. Fairfax, Director
Directorate of Enforcement Programs

Enclosures