In 1979 approximately 497 million pounds of chloromethane were produced in the United States solely for domestic consumption. It is used almost exclusively as an intermediate, primarily in the manufacture of silicone and tetramethyllead. Chloromethane exposure has been reported to result in a wide range of systemic toxicity following both acute and chronic exposure. Although effects on the liver, kidney, heart, and hematopoietic system have been demonstrated in both humans and animals, the most sensitive organ seems to be the central nervous system (CNS). Chloromethane has been reported to possess mutagenic activity in bacterial systems that detect gene mutations and to cause chromosomal aberration. Evidence of its mutagenic activity, its in vitro and in vivo alkylating capabilities, and its structural relationship to known or suspected oncogens suggest that chloromethane may possess oncogenic potential. EPA is also concerned with the danger of both structural malformation and behavioral alterations that may be posed by chloromethane.

Cover title: Assessment of testing needs : chloromethane : support document for proposed health effects test rule, Toxic Substances Control Act, Section 4. "EPA-560/11-80-015." "June 1980." Includes bibliographical references (pages 67-83).