premise: The new health and safety regulations state that helmets should be worn and fastened and the head torch operating at all times whilst working within the mine. The use of other safety devices would be prioritised according to the previous depth regulations and in accordance to the mine's security engineer daily instructions. On dates of detonations maximal safety wear should be implemented inside as well as within a 500 meters external diameter outside the mine with no exception.
hypothesis: Miners working on the upper surface of the mine, near the mine's entrance, are not ever expected to wear safety devices other than a helmet and a head torch.