This guide covers the use of radiation-sensitive indica-tors in radiation processing. These indicators may be labels, papers, or inks which undergo a color change or become colored when exposed to ionizing radiation. The purpose of these indicators is to determine visually whether or not a product has been irradiated, rather than to measure different dose levels.Such materials are not dosimeters and should not be used as a substitute for proper dosimetry. Information about dosimetry systems for ionizing radiation is provided in other ASTM documents (see Guide E 1261).This standard does not purport to address all of the safety problems, if any. associated with its use. It is the responsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.