Mine ventilation safety requires employers to minimise dust, fumes and gas exposure before workers enter confined spaces. An employer of every belowground mine must minimise emissions of gas, fumes, vapours and dust and limit employee exposure to reasonably practicable levels that are not harmful to health. No employee may enter a workplace or confined space until all practicable measures have been taken to remove noxious gas, fumes, vapours or dust and bring levels within permissible limits.