sec.220Where explosive-powered tools may be used

### sec.220 Where explosive-powered tools may be used The person directly supervising and controlling the use of an explosive-powered tool at an underground mine must ensure the place where the tool is used has the following features— a general body concentration of methane of less than 0.5%; its exposed surfaces within a radius of 20m from where the tool was fired are— thoroughly saturated with water; or treated with stonedust so the deposited dust mixture comprises an incombustible coal dust concentration of at least 85%. - (a) a general body concentration of methane of less than 0.5%; - (b) its exposed surfaces within a radius of 20m from where the tool was fired are— (i) thoroughly saturated with water; or (ii) treated with stonedust so the deposited dust mixture comprises an incombustible coal dust concentration of at least 85%. - (i) thoroughly saturated with water; or - (ii) treated with stonedust so the deposited dust mixture comprises an incombustible coal dust concentration of at least 85%. - (i) thoroughly saturated with water; or - (ii) treated with stonedust so the deposited dust mixture comprises an incombustible coal dust concentration of at least 85%.