Under the new regulations a ladder over 24 feet high will require a personal fall arrest system or ladder safety system.
Osha roof ladder.
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.
Osha standard 1910 27 for the safe design and load requirements of fixed ladders appurtenances and fastenings.
What about landing platforms.
Fixed ladders shall be provided with cages wells ladder safety devices or self retracting lifelines where the length of climb is less than 24 feet 7 3 m but the top of the ladder is at a distance greater than 24 feet 7 3 m above lower levels.
You can choose any pfas provided it meets the osha requirements in section 1926 502 d.
Per osha 1910 23 d 4 the side rails of through or sidestep ladders must extend 42 inches above the top of the access level or landing platform served by the ladder.