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Respirable quartz: Geometric mean exposures and percent exceeding designated occupational exposure limits by MSHA coal mine district and state, MSHA inspector and mine operator samples, 1982-2003


- indicates incalculable field.    PEL - permissible exposure limit    REL - recommended exposure limit    GM

Note: The MSHA PEL is 2 mg/m3 MRE for respirable dust containing less than or equal to 5 percent quartz. The PEL is adjusted using the formula [(10 mg/m3 MRE) / (% quartz)] for respirable dust containing greater than 5 percent quartz. See appendices for sourc

Source: MSHA coal mine inspector and mine operator quartz data.

Reference Number: 2008-202

Date Posted: June 2008

Archived Version