TOXICOLOGY OF COLORS AS FOOD ADDITIVES

Abstract

This chapter reviews the toxicology of colors as food additives. It has been noted that there is increasing demand by the U.S. regulatory agencies for information concerning the toxicological profile of these color additive regulations. This trend is increasing around the world. On a worldwide basis, a great variety of colors are presently being used. The 1964 World Health Organization (WHO) document entitled Specifications for Identity and Purity and Toxicological Evaluation of Food Colors serves as a handy reference on this subject. It lists the specifications for 40 synthetic organic colors. The chapter presents the number of synthetic and natural colors permitted in various countries today. Their number varies from a low of seven in Australia to 22 in the United Kingdom. Nine chemical classes are represented by these synthetic colors. The oral LD50's of these food colors are generally about two grams per kilogram body weight in rats. An extensive amount of metabolism work has been reported on edible food colors. While the xanthene, triarylmethane, triphenylmethane, and indigoid dyes pass through the GI tract unchanged with less than 25% being absorbed, less than 10% of the monoazo colors traverse the gastrointestinal tract without being metabolized by the microflora.