Pennsylvania Code › Title 34 - LABOR AND INDUSTRY › Part I - Department of Labor and Industry › Chapter 43 - TUNNEL CONSTRUCTION AND COMPRESSED AIR WORK › Subchapter A - TUNNEL CONSTRUCTION AND WORK IN COMPRESSED AIR › TUNNEL CONSTRUCTION › Section 43.44 - Special protection against gases

Current through Register Vol. 54, No. 28, July 13, 2024
(a)
Amounts.
Each case
					 containing explosives for underground use shall be clearly marked in 1/4 inch
					 or larger type with the designation "fume class 1," "fume class 2" or "fume
					 class 3," to indicate the amount of poisonous gases produced. The amount of
					 poisonous gases produced shall be the total volume of carbon monoxide plus
					 hydrogen sulphide emitted in the Bichel gauge by a 1 1/4 by 8 inch cartridge of
					 the explosive as determined by tests according to the standard procedure of the
					 United States Bureau of Mines. The standard procedure is recorded on pages 91
					 to 94 of the United States Bureau of Mines Bulletin 346 entitled "Physical
					 Testing of Explosives." The gases emitted shall not contain more oxygen than is
					 sufficient to burn the combustible gases to their maximum oxidizable state. The
					 amount of poisonous gases produced per 1 1/4 by 8 inch cartridge shall be less
					 than 0.16 cubic feet for fume class 1, from 0.16 to 0.33 cubic feet for fume
					 class 2, and from 0.33 to 0.67 cubic feet for fume class 3. Explosives in
					 cartridges smaller than 1 1/4 by eight inches shall comply with the limits
					 specified for the fume class of the 1 1/4 by 8 inch cartridge of that
					 explosive.
(b)
Classes.
No explosive other than those in fume class 1 shall
					 be used underground in any operation, except that if conditions in any
					 operation warrant, the Department may, at its discretion, grant permission for
					 use of explosives in fume class 2, or fume class 3 when proper application has
					 been made by an operator.
(c)
Oxygen.
No explosive shall be used underground in any
					 operation if the gases emitted in the Bichel gauge, in tests, according to the
					 standard procedure of the United States Bureau of Mines, contain more oxygen
					 than is sufficient to burn the combustible gases to their maximum oxidizable
					 state. The standard procedure is recorded on pages 91 to 94 of the United
					 States Bureau of Mines Bulletin 346 entitled "Physical Testing of
					 Explosives."
(d)
Packing.
No explosive which is packed in cartridges of less
					 than one inch diameter shall be used underground in any operation.
(e)
Wrapper.
No explosive
					 shall be used underground with its wrapper removed and no additional paper
					 shall be wrapped around the explosive charge.
(f)
Deterioration.
No
					 explosive which has obviously deteriorated due to improper storage, or to any
					 other cause, shall be used underground in any operation.
(g)
Permissible explosives.
Permissible explosives used in underground operations having inflammable gas
					 shall conform to all requirements of the United States Bureau of Mines as to
					 permissibility and are therefore excluded from the requirements of subsections
					 (a) and (b). Periodic tests shall be made for methane or other explosive
					 gases.
(h)
Blasts.
No person shall enter a hazardous area created by a blast involving 25 pounds
					 or more of explosives in any underground operation until at least 15 minutes
					 have elapsed after the blast.
(i)
Ventilation.
The following requirements for ventilation shall
					 be complied with:
(1) No person shall enter or
					 remain in a section containing gases produced by a blast in any underground
					 operation unless the ventilation meets the requirements of this
					 subsection.
(2) Ventilation shall
					 be maintained so that in the breathing zone of the section the concentration of
					 carbon monoxide, as determined by an approved carbon monoxide detector, does
					 not exceed .030% by volume at the time of entrance into the section, and does
					 not exceed .015% at the end of 1 hour after entrance, and .010% at the end of 2
					 or more hours.
(3) This requirement
					 is not intended to prevent entering into, passing through or remaining in
					 localized sections for a period not exceeding 5 minutes in concentrations of
					 carbon monoxide of .060% to .100% or for a period not exceeding 15 minutes in
					 concentrations of carbon monoxide of .030% to .060%.
(4) When the concentration of carbon monoxide
					 and the conditions of exposure to the gas in a section exceed the limitations
					 stated in this subsection, adequate respiratory protection shall be provided
					 for and shall be used by any person entering the section. A contractor or
					 operator shall designate a capable inspector who shall have the following
					 duties:
(i) Make the tests and examinations as
					 are necessary to establish conditions with respect to ventilation and poisonous
					 gas concentrations in sections containing the gases.
(ii) Direct and control the entrance into and
					 periods of exposure of all persons within these sections.
(iii) Keep a dated record of all tests and
					 examinations. The record shall be available for examination by inspectors of
					 the Department at all times.