32.14. Dust
General provisions
32.14.1.
Adequate measures should be taken to prevent the
formation of, or to suppress, all dust in tunnelling operations.
32.14.2.
Particular care should be taken to prevent the forma-
tion of, or suppress, siliceous dusts consisting of particles less than
5 microns in size.
32. 14.3.
Dust should be suppressed as close as possible to its
source.
32.14.4.
The ventilation in tunnelling operations should:
supply air that is as clean as practicable to the workplaces;
effectively dilute and remove airborne dust; and
not have a velocity high enough to raise dust.
32. 14.5.
The air in tunnelling operations should be sampled
for dust at suitable intervals by competent
persons.
Water
32.14.6.
If water is used for the prevention and suppression of
dust, an adequate supply of water should be available in tunnelling
operations.