Question: Would stairs built after January 17, 2017, be in compliance with 29 CFR 1910.25(c)(3) if they have an angle between 49 and 50 degrees and tread depth of 9.5 inches (with 8 inches run and a nosing of 1.5 inches) as shown in the below picture?
Response: No. OSHA’s intention for the 9.5-inch minimum tread depth requirement is to provide stepping space that is adequate to protect employees from falling, which is consistent with national consensus standards for standard stairs (ANSI A1264.1 and NFPA 101). Therefore, the standard requires tread depth to be measured horizontally between the vertical planes of the foremost projection of adjacent treads, and at a right angle to the tread’s leading edge but excluding beveled or rounded tread surfaces that slope more than 20 degrees.
Source: https://www.osha.gov/laws-regs/standardinterpretations/2025-06-17