exhaust ventilation การใช้

If local exhaust ventilation or enclosure is not used, respirators are necessary.
Where possible, operations should be enclosed and the use of local exhaust ventilation at the site of chemical release is recommended.
This may be accomplished by pressurization ( in the case of positively pressurized buildings ), or by depressurization ( in the case of exhaust ventilation systems ).
Dispersion or dilution of dust produced depends on the extent of confinement of the sources and the work area, as well as the presence and effectiveness of exhaust ventilation.
In the UK, the Health and Safety Executive has implemented COSHH regulations to ensure all industrial workplaces protect the health of their employees via effective Local Exhaust Ventilation ( LEV ).