The physical and chemical properties, manufacturing methods, uses, environmental concerns, and toxicity of 1,2‐dichloroethane are discussed. 1,2‐Dichloroethylene, also known as acetylene dichloride, dio‐form, α,β ‐dichloroethylene, and sym ‐dichloroethylene, exists in two isomers cis[156‐59‐2] and trans[156‐59‐2]. This solvent is used as an extraction solvent and as a chemical intermediate for other chlorinated solvents and compounds. The article describes the manufacturing, chemical and physical properties, storage and handling, toxicity, and its common uses. Trichloroethylene, commonly referred to as “tri”, is a widely used vapor‐degreasing solvent. In recent years its popularity has fallen mostly because of environmental restrictions on its use. Trichloroethylene has excellent solvency properties for a large number of natural and synthetic substances. This article includes physical and chemical properties, production, and use information. In addition, safety, toxicological, and environmental regulations pertinent to trichloroethylene are reviewed. Tetrachloroethylene [127‐18‐4], perchloroethylene, tetrachloroethene, commonly referred to as “perc,” is widely used in the dry‐cleaning industry as well as metal cleaning and vapor degreasing because of its excellent solvent properties. It has no flash point or flammable limits in air or oxygen. This article includes the physical and chemical properties of tetrachloroethylene, historical production within the United States, manufacturing locations and processes, as well as typical quality specifications. In addition, safety and toxicological considerations and environmental regulations pertinent to tetrachloroethylene are reviewed. The Montreal Protocol has had an impact on all of the compounds discussed in this article.