Aliphatic Carboxylic Acids, Unsaturated

Abstract

The alkenoic series of carboxylic acids are obtained from such natural sources as animal tallows and greases, and vegetable, coconut, palm, and marine oils. Several have also been produced synthetically from petroleum sources. They are frequently referred to as fatty acids (C 6 to C 24 ) and have important commercial applications in plastics, coating materials, fungicides, food preservatives, lubricants, and perfumes. They have been used as softening agents for rubber and as pharmaceuticals in medicine and dentistry. Acids of this type are unstable and polymerize readily, hence offering important chemical and physical properties for use in producing esters, acid halides, acid amides, and acid anhydrides. As a class, the unsaturated carboxylic acids have been subjected to an extensive battery of studies, including acute, short‐term, and chronic toxicity and carcinogenicity tests and reproductive and developmental toxicity and genotoxicity tests. Overall, these acids have a low level of mammalian toxicity, although they are strong skin and eye irritants in animal tests and are irritating to mucosal membranes in humans. For those acids for which adequate studies have been conducted, there is no evidence that they are reproductive or developmental toxicants or carcinogens. Mutagenicity and clastogenicity studies suggest that this group of acids is devoid of genotoxic activity. The biochemistry of many of these acids can be found in general textbooks. Rapid metabolism to other fatty acids may explain their general low degree of toxicity. The physical properties and acute toxicity of saturated monocarboxylic acids are provided.