This specification covers limestone suitable for use as dust in coal mines to prevent coal dust explosions. The limestone shall conform to the chemical composition requirements prescribed. The chemical analysis and the particle size analysis of the limestone shall be conducted.

1.1 This specification covers limestone suitable for use as dust in coal mines to prevent coal dust explosions.

Note 1—Limestone can serve as a source of incombustible material in coal mine operations. Limestone is dusted onto coal exposures in sufficient amount so that not less than 65 % of all loose dust shall be limestone incombustible material. In return air courses the concentration of incombustible materials should be not less than 80 % of the total dust (MSHA 30 CFR 75.403). With such a concentration of limestone incombustible material, dust explosions cannot initiate or be propagated from nearby gas explosions. The limestone must be substantially dry in order to dust satisfactorily.

1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

1.3 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.