Paragraph 5

It shall be the duty of the manager of every mine to make and ensure the efficient carrying out of arrangements to secure that, as respects every length of road to which this Part of these regulations applies and which is required to be ventilated, any dust on the floor, roof or sides thereof which can be raised into the air shall contain not less than the minimum percentage of incombustible matter determined in accordance with the schedule to these regulations in relation to coal in connection with the working of which that length of road is used.

For the purposes of these regulations the incombustible matter in any dust includes moisture contained therein.