OSHA Instruction STD 1-1.11 APR 26, 1982 Office of Compliance Programming

Subject: The alternating Tread Type Stair

A. Purpose. This instruction recognized a newly developed alternating treat type stair not presently covered by existing OSHA standards.

B. Scope. This instruction applies OSHA-wide.

C. Action. OSHA Regional Administrators/Area Directors shall take action to ensure that employers using alternating tread type stairs comply with the guidelines in E. of this instruction.

D. Federal Program Change. This instruction describes a Federal program change which affects State programs. Each Regional Administrator shall:

1. Ensure that this change is forwarded to each State designee.

2. Explain the technical content of the change to the State designee as requested.

3. Ensure that State designees are asked to acknowledge receipt of this Federal program change in writing, within 30 days of notification, to the Regional Administrator. This acknowledgment should include a description either of the State's plan to implement the change or of the reasons why the change should not apply to that State.

4. Review policies, instructions and guidelines issued by the State to determine that this change has been communicated to State program personnel. Routine monitoring activities (accompanied inspections and case file reviews) shall also be used to determine if this change has been implemented in actual performance.

OSHA Instruction STD 1-11.1 APR 26, 1982 Office of Compliance Programming

E. Guidelines. Currently OSHA has no standards relating to the alternating tread type stair. In order to provide safety for employees who might use such stairs, it must be designed, installed, used and maintained in accordance with the manufacturer's recommendations and in accordance with the following requirements:

1. The stair will be installed at a 70-degree angle or less.

2. The stair shall be capable of withstanding a minimum uniform load of 100 pounds per square foot with a design factor of 1.7 and the treads shall be capable of carrying a minimum concentrated load of 300 pounds at the center of any treadspan or exterior arc with a design factor of 1.7. If intended for greater loading, construction shall allow for that loading.

3. The stair shall be equipped with a handrail on each side to assist the user in climbing or descending the stair.

F. Background. The Directorate of Safety Standards Programs will propose standards for the alternating tread type stair when the Subpart D Proposal is published in the Federal Register. Based on a National Office review, it appears that if the stair meets the design requirements in E. of this instruction and is properly installed, used and maintained, it meets the intent of the Act.

Thorne G. Auchter Assistant Secretary

DISTRIBUTION: National, Regional and Area Offices All Compliance Officers State Designees NIOSH Regional Program Directors