When building or retrofitting industrial machinery (packaging lines, presses, conveyors), your stairways to maintenance platforms must follow Part 3. Your design software (CAD) should reference these dimensions.
Stairways with more than 3 risers or a height exceeding 500 mm require guard-rails. din en iso 14122-3 pdf
The standard details specific dimensions and construction requirements to minimize risks such as slipping, tripping, or falling. INTERNATIONAL STANDARD ISO 14122-3 - Cloudfront.net din en iso 14122-3 pdf