Coal Dust Particle Size Surveys

August 2009
NIOSH Docket Number 174

The National Institute for Occupational Safety and Health (NIOSH) and MSHA conducted a joint survey to determine the range of coal particle sizes found in dust samples collected from intake and return airways of U.S. coal mines. Results from this survey show that the coal dust found in mines today is much finer than in mines of the 1920s, presumably due to increased automation and a greater reliance on mining machinery.

Given the results of the recent coal dust particle size survey and large-scale explosion tests, NIOSH recommends a new standard of 80% total incombustible content be required in the intake airways of bituminous coal mines.

Notice of draft publication available for public comment; 74 FR 42317; 8/21/09pdf icon [PDF – 2,303 KB]

Draft NIOSH document, “Recent Coal Dust Particle Size Surveys and the Implications for Mine Explosions;” 10/1/09pdf icon [PDF – 33,636 KB]

Report of Investigations RI9679: Recommendations for a new rock dusting standard to prevent coal dust explosions in intake airways; NIOSH 2010-151; 5/1/10pdf icon [PDF – 1,154 KB]

NIOSH responses to comments received on document; 5/1/10pdf icon [PDF – 8,721 KB]


Submission to the docket from Leeming (Health and Safety Executive (UK)) – 8/14/09pdf icon [PDF – 467 KB]

Submission to the docket from Parsons (United Mine Workers of America) – 9/15/09pdf icon [PDF – 8,284 KB]

Page last reviewed: July 6, 2010