Adequate ventilation of coal mine working faces is the most important technique for controlling respirable dust and methane. Choosing the right technique presents some tough questions. Bureau of Mines research has shown that to control respirable dust, dust must be contained near the face, keeping rollback (turbulence) to a minimum. For methane,the most effective approach has been to use a blowing brattice, or tubing, and to create turbulence and disperse the face methane, allowing it to pass over the machine and into the return. It is immediately apparent that the two approaches may counteract one another, thus complicating the decision as to which system may be best for a given situation. At present, Bureau research has developed two successful machine-mounted face ventilation systems to meet these different needs and allow deeper cutting. The fan-powered dust scrubber is designed to control dust primarily associated with blowing face ventilation systems. The sprayfan controls methane on exhaust-ventilated sections.