 In arresting a fall in a controlled manner, the distance required to arrest the fall must be considered.Federal OSHA limits the fall distance to unless the specific system is designed by a "qualified person" meeting the requirements of OSHA 29CFR1910.66 appendix c. The user also may not fall so as to strike protrusions or adjoining walls during the fall.The safe fall distance is a function of the fall factor and the deployment of the "energy absorbers".