Document NG3Na40vXK84xkqw0B4BRLzd8

Document Mo. 26 11 October 1974 Mlneraloglcal Definition* of Term* Relating to Naturally Occurlng Inorganic Flbera asbestlform - mineral structured in the form of aebeatos aebeatoa - generic term for naturally-occurlng inorganic hydrated elllcates that, when proceaaed separate into fibrils. Minerals defined as asbestos are the asbeatlform varieties of the following; serpentine (ehrysotlle), rlebecklte (crocldollte), cuamlngtonlte (amoslte), anthophylllte, treaollte, and actinolite. fiber - for the purpose of this standard, fiber means naturally-occurlng inorganic fiber. fibril - a single crystal in the form of a fiber. fibrous particulate - for the purpose of this standard, fibrous particulate designates fibers, fiber fragments and fiber agglomerates. naturally-occurlng Inorganic fiber - form of mineral characterised by properties of flexibility and length-to-vidth ratio in the order of 100, composed of definite crystal unit cells oriented with respect to a specific axis. Note 1 - The designated 100:1 aspect ratio is considered to represent a reasonable lower limit for naturally-occurlng mineral fibers. Fibers of these dimensions can be broken into parts of fibers that may maintain their eame surface properties and activities. Therefore fiber fragments may have to be evaluated for atmospheric monitoring purposes. However, attempting to define a fiber by its aspect ratio alone is inadequate since it is obvious that particles of non-flbrous mineral do not become fibers as their aspect ratio increases through comminution. 8005 1257 PRODUCED BY FORD