(1)There shall be maintained at every mine having working belowground a dust plan on a scale having representative factor of not less than 2000 : 1, clearly showing by distinctive colours, code letter and or numbers, the separate areas: -(i)which are naturally wet;(ii)which require treatment with water indicating the system of water pipe lines laid down for the purpose; and(iii)which require treatment with incombustible dust at such intervals of 24 hours, 7 days, 14 days, 30 days, three months or other specified period as the case may be.Explanation: The intervals referred to in clause (iii) shall be based on the results of analysis of routine mine dust samples collected from the areas concerned.(2)The areas referred to in sub-regulation (1) shall be clearly demarcated in the working belowground by means of suitable notice boards or by other suitable means.(3)Every part of mine which is not naturally wet throughout or which is not isolated by explosion-proof stoppings shall be treated -(i)with fine incombustible dust in such manner and at such intervals as will ensure that the dust on the floor, roof and sides and any support or structure shall always consist of a mixture containing not less than 75% of incombustible matter in case of coal seams containing less than 30% volatile matter (on dry ash free basis) and 85% of incombustible matter in case of coal seams containing more than 30% of such volatile matter; or(ii)with water in such manner and at such intervals as will ensure that the dust on the floor, roof and sides or any support or structure is always combined with not less than 30% by weight of water in intimate mixture; or(iii)in such manner as the Regional Inspector may approve by an order in writing.(4)The incombustible dust used for the purpose of sub-regulation (3) shall be -(i)such that it does not contain more than 5% of free silica;(ii)of such fineness and character, that it is readily dispersible into the air and that, when used in plates which are not directly made wet by water from the strata it does not cake but it is dispersed into the air, when blown upon with mouth or by a suitable appliance; and(iii)as far as practicable light in colour.(5)No incombustible dust shall continue to be used if it is found by tests which shall be carried out once at least in every three months, not to comply with the foregoing requirements:Provided that when the supply of incombustible dust used in a mine is not from a regular source, these tests shall be carried out whenever a fresh supply of incombustible dust is received.(6)Where any place or part of the mine is to be treated with incombustible dust -(i)before treating with incombustible dust, all coal dust shall be cleaned, as far as practicable, from the roof, sides, floor, props, cogs, bars, brattice cloth or any other objects or structure or place on which coal dust may deposit, and all dust so collected shall be removed to the surface within 24 hours;(ii)incombustible dust shall be spread on the objects, structure and places aforesaid in adequate quantity and at such intervals as may be necessary to censure compliance with the provisions of this sub-regulation;(iii)the cleaning of coal dust and spreading of incombustible dust shall be carried out in the direction of the flow of the air;(iv)a sufficient supply of incombustible dust shall be kept readily available at suitable places in the mine, and any deficiency in the supply of dust underground shall immediately be brought to the notice of the manager; and(v)incombustible dust stacked at different places and kept on pans or on dust barriers in the mine shall be changed whenever it is no longer readily dispersible or whenever fever it becomes coated with coal dust, such dust shall be removed.(7)A daily record of the areas cleaned of coal dust and of the areas treated with incombustible dust or with Water and the amount of incombustible just used shall be maintained in a bound paged book kept of the purpose and every entry in this book shall be signed and dated the dust in-charge, and countersigned by the manager or the ventilation officer.(8)The dust control measures shall be carried out under the supervision of a competent person holding a manager's or overman's certificate or a degree or diploma in mining or mining engineering from a university or institution approved by the Central Government and no duties with respect of sampling of dust under regulation 148 shall, be entrusted to this person who may be designated as the Dust In-Charge, nor any other duties shall be entrusted to such person except with the previous permission of the Regional Inspector.Provided that in the case of a mine having an average monthly output of less than 5000 tonnes, the Dust Incharge shall act as the Sampling In-charge referred to in regulation 148.(9)The Dust Incharge shall ensure -(a)that every part of the mine which, under these regulations requires treatment with water, is thoroughly drenched or sprayed with water immediately before firing shots and also at intervals during the working hours so as to strictly comply with the provisions of regulation 147(3) (ii);(b)that every part of the mine which, under these regulations can be treated with incombustible dust, is so treated as to Strictly comply· with the provisions of regulation 147(3) (i); and(c)that the arrangements for treating with water or incombustible dust as aforesaid are maintained in good order.
