[Code of Federal Regulations]
[Title 42, Volume 1]
[Revised as of October 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 42CFR84.70]

[Page 519]
 
                         TITLE 42--PUBLIC HEALTH
 
    CHAPTER I--PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN 
                                SERVICES
 
PART 84_APPROVAL OF RESPIRATORY PROTECTIVE DEVICES--Table of Contents
 
              Subpart H_Self-Contained Breathing Apparatus
 
Sec. 84.70  Self-contained breathing apparatus; description.


    (a) Self-contained breathing apparatus, including all completely 
assembled, portable, self-contained devices designed for use as 
respiratory protection during entry into and escape from or escape only 
from hazardous atmospheres, are described as follows:
    (1) Closed-circuit apparatus. An apparatus of the type in which the 
exhalation is rebreathed by the wearer after the carbon dioxide has been 
effectively removed and a suitable oxygen concentration restored from 
sources composed of:
    (i) Compressed oxygen; or
    (ii) Chemical oxygen; or
    (iii) Liquid-oxygen.
    (2) Open-circuit apparatus. An apparatus of the following types from 
which exhalation is vented to the atmosphere and not rebreathed:
    (i) Demand-type apparatus. An apparatus in which the pressure inside 
the facepiece in relation to the immediate environment is positive 
during exhalation and negative during inhalation; or
    (ii) Pressure-demand-type apparatus. An apparatus in which the 
pressure inside the facepiece in relation to the immediate environment 
is positive during both inhalation and exhalation.
    (b) The following respirators may be classified as designed and 
approved for use during emergency entry into a hazardous atmosphere:
    (1) A combination respirator which includes a self-contained 
breathing apparatus; and
    (2) A Type ``C'' or Type ``CE'' supplied air respirator, where--
    (i) The self-contained breathing apparatus is classified for 3-, 5-, 
or 10-minute service time and the air line supply is used during entry; 
or
    (ii) The self-contained breathing apparatus is classified for 15 
minutes or longer service time and not more than 20 percent of the rated 
capacity of the air supply is used during entry.
    (c) Self-contained breathing apparatus classified for less than 1 
hour service time will not be approved for use during underground mine 
rescue and recovery operations except as auxiliary equipment.
    (d) Self-contained breathing apparatus classified for less than 30 
minutes' service time will not be approved for use as auxiliary 
equipment during underground mine rescue and recovery operations.