This publication (microfiche only) is the July 1981 issue of selected subfiles of the National Institute for Occupational Safety and Health (NIOSH) Registry of Toxic Effects of Chemical Substances (RTECS). The three subfiles included herein are Tumorigenic citations, Mutagenic citations, and Reproductive Effects citations. The purpose of compiling these subfiles is to identify in one document those substances that have been reported in the literature as having tumorigenic, mutagenic, or reproductive activity. In addition, the Tumorigenic Citations Subfile includes substances that have been or are being tested under the National Toxicology Program's carcinogenesis testing program and substances that have been reviewed by the United Nation's International Agency for Research of Cancer, regardless of whether the test results and reviews were positive, negative, or indefinite. These compilations should provide a ready reference to the literature, and should be useful to employees and employers, occupational health physicians, industrial hygienists, toxicologists, and researcher. In turn, this information may contribute to a better understanding of potential occupational hazards and ultimately may help to achieve a more healthful workplace.