[Code of Federal Regulations]
[Title 30, Volume 1]
[Revised as of July 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 30CFR90.100]

[Page 654]
 
                       TITLE 30--MINERAL RESOURCES
 
  CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR
 
PART 90--MANDATORY HEALTH STANDARDS--COAL MINERS WHO HAVE EVIDENCE OF THE DEVELOPMENT OF PNEUMOCONIOSIS--Table of Contents
 
           Subpart B--Dust Standards, Rights of Part 90 Miners
 
Sec. 90.100  Respirable dust standard.


    After the twentieth calendar day following receipt of notification 
from MSHA that a Part 90 miner is employed at the mine, the operator 
shall continuously maintain the average concentration of respirable dust 
in the mine atmosphere during each shift to which the Part 90 miner in 
the active workings of the mine is exposed at or below 1.0 milligrams 
per cubic meter of air. Concentrations shall be measured with an 
approved sampling device and expressed in terms of an equivalent 
concentration determined in accordance with Sec. 90.206 (Approved 
sampling devices; equivalent concentrations).