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Aliphatic carboxylic acids include a very wide range of chemicals that perform a diverse range of industrial functions. Many occur naturally and serve an important function in nutrition, and others are intermediates in normal biochemical processes. This chapter is limited to a discussion of the saturated aliphatic mono- and polycarboxylic acids. Because of the wide range of uses, the differing circumstances of isolation and often the complexity of structure, many organic acids are described by a variety of names. In this chapter, the names used in the text are usually the trivial or most common names; alternative names are given for reference. A current systematic or Chemical Abstracts acid name is given in the tables that describe physicochemical properties. The commercial and industrial importance of this class of compounds is indicated by recent production figures: formic acid has a production volume in excess of 1 billion lb/year, acetic acid has a production volume in the region of 3.3 billion lb/year, acrylic acid in excess of 1 billion lb/year, and propionic acid on the order of 100 million lb/year. Esters and salts of organic acids are also produced in large volumes. In general, serious physiological concerns for humans do not arise from the acids discussed in this chapter. Occasionally, concerns have been reported for individual acids, but usually with very high experimental or accidental exposures. The low level of concern associated with most of these acids is attested to by many members of this class that are used as food additives, flavoring agents, and stabilizers, or as food materials. The primary adverse effect of exposure to aliphatic carboxylic acids is usually acute arising from their primary irritant effects on skin, eyes, and mucous membranes, particularly of the short-chain acids. As the molecular weight increases and the water solubility decreases, the irritating capacity of a carboxylic acid generally decreases. In addition, skin sensitization is quite rare with the aliphatic carboxylic acids. Keywords: aliphatic carboxylic acids; farm workers; health effects; industrial applications; metabolic fate; saturated |
