ISA 12.10

Abstract

This standard refers only to combustible mixtures created by dusts &#8212; such as agricultural, carbonaceous, plastic, chemical, and metal dusts. Such materials are classified in NEC ^&#174; Article 500 as Class II, Groups E, F, and G. <br>This standard classifies a location based on its dust cloud concentration, its accumulated combustible dust layer thickness, and its dust bulk resistivity; it also contains references to, and data on, the explosivity of common dusts, as well as references to laboratory equipment and test procedures for evaluating the explosivity of dusts. <br>This standard is intended for use by persons trained in the design and installation of instrument systems and by inspection authorities in the approval of such installations. <br><strong>NOTE</strong>: This standard is not intended to address hazards created by the emission of Class I combustible gases from combustible dusts, e.g., the emission of methane from freshly crushed coal. <br><strong>Purpose</strong> <br>This standard recommends procedures for classifying locations made hazardous by the presence of a cloud or blanket of combustible dust. It conforms with the <em>U.S. National Electrical Code ^&#174; (NEC ^&#174;)*</em> <em>and the Canadian Electrical Code (CEC)</em>, and is intended to expand and clarify both. <br>*National Electrical Codes^&#174;and NEC^&#174; are registered trademarks of the National Fire Protection Association, Inc., Quincy, Mass.