D.C. Mun. Regs. tit. 24, r. 24-3211
A window cleaner using a safety belt shall attach one (1) belt terminal to the anchor before stepping out onto the sill, and one (1) belt terminal shall remain attached to the anchor while stepping back into the building.
During the operation of window cleaning, both belt terminals shall be attached to the anchors.
Safety belts shall be maintained in good repair at all times.
Each window cleaner's safety belt shall be examined frequently by the person employing, directing, or permitting the window cleaner to clean windows, and shall also be examined by the window cleaner before being used each day.
No belt shall be used that does not provide the safety as required by this chapter.
All belts shall be stored and handled so that rust or injury to them is prevented.
No belt shall be used that has been affected by mildew, by the action of acid, or by any other corrosive or deteriorating agent.
Safety belts shall not be stored in the same room with acids.
Safety belts shall not be stored where they are likely to come in contact with sharp-edged tools or equipment.
Belt straps that have been worn or cut so as to show broken fabric threads shall be replaced by new straps.
No belt terminal shall be used if any point in the slot will accommodate a nine-sixteenth inch (9/16 in.) plug gauge.
No link shall be used in the belt terminal strap if any cross-sectional dimension of the link is less than three-thousandths of an inch (0.300 in.).
D.C. Mun. Regs. tit. 24, r. 24-3211