{"data":{"id":"us/29-cfr-1917.121","jurisdiction":"us","citation":"29 CFR 1917.121","heading":"Spiral stairways.","body":"(a) Definition. “Spiral stairway” means one with closed circular form, uniform sector-shaped treads and a supporting column.\n(b) Requirements. Spiral stairways shall meet the following requirements:\n(1) Stairways shall conform to the minimum dimensions of Figure F-1;\nSpiral Stairway—Minimum Dimensions\nA (half-tread width) B\nNormal use by employees 11 inches (27.94 cm) 6 inches (15.24 cm).\nLimited access 9 inches (22.86 cm) 5 inches (12.7 cm).\n(2) Stairway risers shall be uniform and shall range from 6 1/2 to 10 1/2 inches (16.5 to 26.67 cm) in height;\n(3) Minimum loading capability shall be 100 pounds per square foot (4.79kN), and minimum tread center concentrated loading shall be 300 pounds (1334 N);\n(4) Railings shall conform to the requirements of § 1917.112(c)(1). If balusters are used, there shall be a minimum of one per tread. Handrails shall be a minimum of 1 1/4 inches (3.18 cm) in outside diameter; and\n(5) Vertical clearance shall be at least 6 feet, 6 inches (1.98 m) above the top step.\n(c) Maintenance. Spiral stairways shall be maintained in safe condition.","path":["Title 29—Labor","Subtitle B—Regulations Relating to Labor","CHAPTER XVII—OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR","PART 1917—MARINE TERMINALS","Subpart F—Terminal Facilities"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-29.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:25:20Z","sha256":"0ed9378d65fe26d81c0f86d93e0abfacc3d785cf4c5732c3dd9ab57efb656200","source_id":"us-cfr","stale":true,"prev":"us/29-cfr-1917.120","next":"us/29-cfr-1917.122"},"notice":"GroundRules: Original legal text. Not legal advice."}