[Code of Federal Regulations]

[Title 30, Volume 1]

[Revised as of July 1, 2006]

From the U.S. Government Printing Office via GPO Access

[CITE: 30CFR33.33]



[Page 167]

 

                       TITLE 30--MINERAL RESOURCES

 

  CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR

 

PART 33_DUST COLLECTORS FOR USE IN CONNECTION WITH ROCK DRILLING IN COAL 

MINES--Table of Contents

 

                       Subpart C_Test Requirements

 

Sec.  33.33  Allowable limits of dust concentration.



    (a) The concentration of dust determined by the control sample shall 

be subtracted from the average concentration of dust determined by the 

test samples collected at each drill operator's position, and the 

difference shall be designated as the net concentration of airborne 

dust. Calculations of the average concentration of dust determined from 

the test samples shall be based upon the results of not less than 80 

percent of each set of test samples.

    (b) Under each prescribed test condition, the net concentration of 

airborne dust at each drill operator's position shall not exceed 10 

million particles (5 microns or less in diameter) per cubic foot of air 

when determined in accordance with the method given in Sec.  33.32(a).



[Sched. 25B, 25 FR 6473, July 9, 1960, as amended at 26 FR 2599, Mar. 

28, 1961]



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