[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: 30CFR71.702]



[Page 448]

 

                       TITLE 30--MINERAL RESOURCES

 

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

 

PART 71_MANDATORY HEALTH STANDARDS_SURFACE COAL MINES AND SURFACE WORK 

AREAS OF UNDERGROUND COAL MINES--Table of Contents

 

                     Subpart H_Airborne Contaminants

 

Sec.  71.702  Asbestos dust standard; measurement.



    (a) The 8-hour average airborne concentration of asbestos dust to 

which miners are exposed shall not exceed two fibers per cubic 

centimeter of air. Exposure to a concentration greater than two fibers 

per cubic centimeter of air, but not to exceed 10 fibers per cubic 

centimeter of air, may be permitted for a total of 1 hour each 8-hour 

day. As used in this subpart, the term asbestos means chrysotile, 

amosite, crocidolite, anthophylite asbestos, tremolite asbestos, and 

actinolite asbestos but does not include nonfibrous or nonasbestiform 

minerals.

    (b) The determination of fiber concentration shall be made by 

counting all fibers longer than 5 micrometers in length and with a 

length-to-width ratio of at least 3 to 1 in at least 20 randomly 

selected fields using phase contrast microscopy at 400-450 

magnification.



[41 FR 10223, Mar. 10, 1976. Redesignated at 45 FR 80756, Dec. 5, 1980]