Current through Register Vol. 54, No. 50, December 14, 2024
Section 43.44 - Special protection against gases(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.(j)Fresh air. The minimum amount of fresh air introduced into the shaft or tunnel heading of any construction project shall be the larger of the two following alternatives: (1) 100 cubic feet per minute per man occupying the section within 200 feet of the blasted face.(2) Five cubic feet per minute per cartridge of explosive used in blasting that face.(k)Delay electric blasting caps. In all blasts involving delay electric blasting caps in shafts or tunnels, each shot hole shall be adequately stemmed with noncombustible material or the explosives confined in some other manner approved by the Department.(l)Internal combustion engine. No internal combustion engine may be used in any shaft or tunnel of a construction project unless it has been approved by the Department.