(a) In dangerously dusty locations, electric motors, switches, and controls shall be of dust-tight construction or enclosed with reasonably dust-tight housing or enclosures. Open-type motors, switches, or controls now in use in tipples and cleaning plants in dusty locations may be continued in use until such dust-tight equipment can be procured or until they can be corrected with reasonably dust-tight housing or enclosures.
(b) Structures shall be kept free of excessive coal dust accumulations.
(c) Where coal is dumped at or near air intake openings, reasonable provisions shall be made to prevent the dust from entering the mine.
(d) Where repairs are being made to the plant, proper scaffolding and proper overhead protection shall be provided for workmen wherever necessary.
(e) Welding shall not be done in dusty atmosphere or dusty locations, and firefighting apparatus shall be readily available during welding.