PART XVIII EXCAVATION, UNDERGROUND WORK AND ROCK CRUSHING — Air quality

Effective dust-control measures shall be employed during the handling and loading of broken rock.

the respirable air in all underground workings is free from hazardous amounts of dusts, vapours and gases, and does not contain less than 20% oxygen; and the use of suppression;

appropriate tests for harmful vapour, gases, fumes, mists, dusts or explosive substances and oxygen deficiency are made and recorded dust removal by mechanical means; or

before entry, (ii) after an interruption in the work procedures, and (iii) at appropriate intervals.

An employer who employs workers at a mine or quarry where silica is mined or quarried, or where it is present, shall comply with the Silica Code of Practice.

The tests required under paragraph (1)(b) shall be performed by a person who has appropriate training in the proper use of testing and monitoring equipment.

A worker employed in surface rock-excavating workings shall be protected from harmful dust concentrations by

another acceptable engineering control.

Where a worker is exposed to dusting resulting from loading, transporting or conveying rock at surface operations, the dust shall be reduced to non-harmful concentrations by the application of water or by other effective methods.

An employer shall ensure that dust caused by drilling or handling rock at underground rock-excavating workings is effectively suppressed by a means acceptable to the division.

A rock drill, that is, a machine or device for drilling a hole in rock for the purpose of blasting, usually powered by compressed air but in which electricity or steam may be used, shall be equipped with a water jet, spray or other device acceptable to the minister to effectively suppress drilling dust.

Subsection (7) does not apply to hand-drilling procedures.

A water spray shall be used in every development heading unless written permission has been received from the assistant deputy minister to work the heading without a water spray.

Mechanical ventilation shall be provided to produce a minimum air volume of 15.24 cubic metres a minute a square metre of working face in the work area.