You can choose any pfas provided it meets the osha requirements in section 1926 502 d.
Osha roof ladder.
Ladder rungs steps and cleats have a minimum clear width of 11 5 inches 29 cm on portable ladders and 16 inches 41 cm measured before installation of ladder safety systems for fixed ladders except that.
For starters prior to the new ruling the only real guidance on fixed ladders came from the construction standards osha more 1926 1053 a 18 required the use of cages wells ladder safety devices or self retracting lifelines for fixed ladders of 24 feet or more.
Under the new regulations a ladder over 24 feet high will require a personal fall arrest system or ladder safety system.
Osha standard 1910 27 for the safe design and load requirements of fixed ladders appurtenances and fastenings.
A ladder that is less than 24 feet high does not require a fall arrest system of any sort.
What about landing platforms.