A technique being used abroad to suppress or prevent the formation of dust, in advance of mining a coal seam. Water (or sometimes foam or steam, which is costlier but more effective) is injected into the coal ahead of the face through long drill holes, as many as four to six per face and 6 to 20 m in length. The liquid infuses into the seam along fractures and cracks and, under pressure, penetrates a considerable distance from the hole radially, wetting the coal well. It has proved very effective in reducing dust concentrations during subsequent mining--in some instances, as much as 80%. Water infusion originated in Great Britain (it is used in 25% of the dusty mines) and has been tried experimentally with some success in the United States.