This publication details recommendations for a new rock dusting standard to prevent coal dust explosions in intake airways.

At the request of the Mine safety and Health Administration (MSHA) and the West Virginia Office of Miners' Health, Safety, and Training, the NIOSH's Pittsburgh Research Laboratory evaluated the effects of explosions on specific mine ventilation seals at its Lake Lynn Experimental Mine to assist the agencies in their investigations of the explosion at the Sago Mine in West Virginia, which occurred on January 2, 2006. Six full-scale explosion tests were conducted to help answer questions regarding possible scenarios for the Sago explosion. NIOSH's findings and recommendations are documented within.

This report presents nearly all structural data available from explosion tests of 20-psi mine ventilation seals and concrete-block ventilation stoppings that were conducted by the NIOSH during 1997-2008. Although the seals tested were designed to meet the former federal 20-psi pressure design standard, the structural information contained herein on these seal tests will facilitate the analysis and design of coal mine seals that meet the new explosion pressure criteria of 50 and 120 psi as set forth in the Mine safety and health Administration's final rule on "Sealing of Abandoned Areas."

nThe National Institute for Occupational Safety and Health (NIOSH)'s Pittsburgh Research Laboratory conducted a full-scale test of a composite polyurethane-aggregate seal in a hydrostatic chamber at the Lake Lynn Experimental Mine. The report details the test results of the composite polyurethane-aggregate seal and provides an analysis of those results in terms of the seal's structural behavior.

This report discusses the construction techniques, testing methods, and explosion test data collected for the pumpable cementitious seals; the seal, stopping, and overcast designs for the Australian program; and the Packsetter preloaded solid-concrete-block seal.