FAO Nutrition Meetings Report Series No. 40A,B,C WHO/Food Add./67.29 TOXICOLOGICAL EVALUATION OF SOME ANTIMICROBIALS, ANTIOXIDANTS, EMULSIFIERS, STABILIZERS, FLOUR-TREATMENT AGENTS, ACIDS AND BASES The content of this document is the result of the deliberations of the Joint FAO/WHO Expert Committee on Food Additives which met at Rome, 13-20 December, 19651 Geneva, 11-18 October, 19662 1 Ninth Report of the Joint FAO/WHO Expert Committee on Food Additives, FAO Nutrition Meetings Report Series, 1966 No. 40; Wld Hlth Org. techn. Rep. Ser., 1966, 339 2 Tenth Report of the Joint FAO/WHO Expert Committee on Food Additives, FAO Nutrition Meetings Report Series, 1967, in press; Food and Agriculture Organization of the United Nations World Health Organization 1967 CHLORINE Chemical name Chlorine Empirical formula Cl2 Molecular weight 70.91 Use For the treatment of flour. In the absence of adequate chemical data from the manufacturers, specifications for chlorine have not been prepared and will not be established until the biological studies requested have been made available. Biological Data Biochemical aspects Chlorine oxidizes the flour protein in a manner that is presumed to resemble the effect of other oxidizing agents. In addition to modifying the sulfur-containing amino acids, chlorine may also enter into combination with proteins and unsaturated fatty acids. Halogenated proteins appear to behave nutritionally similarly to normal proteins but halogenation of polyunsaturated fatty acids, on the other hand, may alter their biological activity. Thus, for example, halogenated linoleic acid my cease to be effective as an essential fatty acid. Over-treatment of flour with 1950 ppm of chlorine resulted in the reduction of the unsaturated fatty acids in the flour to 40 per cent., as compared with the untreated flour. Oleic acid was probably converted into dichlorostearic acid, and linoleic and linolenic acids into a range of chlorinated compounds (Coppock et al., 1960). Treatment with up to 120 ppm did not materially change the major fatty acids (Daniels, 1960). When soft-wheat flours ware treated with chlorine, the chlorine content of the lipids increased markedly, the water soluble components to a lesser extent and the gluten only slightly. The lipids and water-soluble compounds comprised only 5 per cent. of the flour, but contained more than 90 per cent. of the added chlorine. The chlorine-containing lipids showed a decreased iodine value (Gilles et al., 1964). The chlorine content of unbleached flour was found to be 43-54 mg Cl per 100 g of flour, and that of bleached flour, 131-189 mg Cl per 100 g. This author found that nearly all the additional chlorine was in water-solubles and gluten. At least 50 per cent. of the Cl in the gluten fraction was in the lipid. In the untreated flour, 70 per cent. is prime starch and this contained 20-25 per cent. of the Cl; treatment with chlorine did not, however, significantly increase the Cl in the prime starch (Sollers, 1961). Rats fed 4.1 per cent. of lipids extracted from chlorine-treated flour showed a decrease of polyunsaturated fatty acids in the fat depots and a corresponding increase of palmitic, oleic and palmitoleic acids when compared with control animals receiving 4.1 per cent. of added untreated flour lipid. The chlorine content of the adipose tissue was, however, only slightly increased. Effects of this nature could not be demonstrated at lower levels of fat intake more comparable with the amounts that might be ingested from the use of treated flour (Daniels et al., 1963). Acute toxicity No data are available. Short-term studies Rat. Five-groups of 3 rats were each fed diets containing 0, 0.82 and 4.1 per cent. of untreated flour lipids, and 0.82 and 4.1 per cent. of lipid from flour treated with chlorine at a level of 1950 ppm. At the 4.1 per cent. level the groups receiving lipid from the treated flour had thinner and rougher fur, fertility was reduced and lactation was also less efficient. Similar depression of fertility and lactation was observed with the group receiving 0.82 per cent. of treated lipid. These effects were consistently observed through 4 generations and were not relieved by 8 weeks feeding of 2 per cent. linoleic acid (Daniels et al., 1960). Dog Two groups of 4 and 6 dogs were fed diets containing flour treated with 356 ppm of chlorine for 21-38 days without causing running fits. Dogs which had developed running fits on agene-treated flour recovered on being switched to chlorine-treated material (Arnold, 1949; Radomski et al., 1948; Bentley et al., 1948; Newell et al., 1947). Long-term studies Rat. A multigeneration study was started in 1955 and continued to the sixth generation until 1963. The animals received drinking-water containing an excess of 100 ppm of chlorine. There was no adverse effect on growth, fertility or mean life-span. There was no indication of a carcinogenic effect of the chlorinated water (Druckrey, 1965). Comments The evidence available indicates that the effects on lipids are not of any great significance. The small change in polyunsaturated fatty acids that occurs at the commercial levels of treatment suggests that this effect is not significant in relation to the human diet as a whole. It seems unlikely that the chlorinated lipids have any significant toxic properties. There is a need for studies on chlorine-treated flour. Evaluation Formal evaluation is not possible on the limited evidence available. Although it does not seen likely that the ingestion of chlorine-treated flour amounting to only 1.5 per cent. of total flour intake will have any serious toxicological significance, it seems desirable nevertheless, that more adequate toxicological and nutritional studies should be carried out. It is not considered necessary to discontinue the use of chlorine at present. Further work required Adequate long-term studies are needed on flour treated with chlorine at several dose levels and bread baked from it. REFERENCES Anon (1960) Brit. med. J., i, 1466 Arnold, A. (1949) Cereal Chem., 26, 46 Bentley, H. R., Booth, R. G., Green, E. N., Heathcote, J. G., Hutchinson, J. B.& Moran, T. (1948) Nature, 161, 126 Coppock, J. B. M., Daniels, N. W. R. & Russell Eggitt, P. W. (1960) Chem. and Ind., 17 Daniels, D. G. H. (1960) J. Sci. Food Agric., 11, 664 Daniels, N. W. R., Frape, D. L., Russell Eggitt, P. W. & Coppock, J. B. M. (1963) J. Sci. Food Agric., 14, 883 Druckrey, H. (1965) Unpublished report submitted to WHO Gilles, K. A., Kaelbe, E. F. L. Youngs, O. L. (1964) Cereal Chem, 41, 412 Newell, G. W., Erickson, R. C., Gilson, W. E., Gershoff, S. N. & Elvejhem, C. A. (1947) J. Amer. med. Assoc., 135, 760 Radomski, J. L., Woodard, G. & Lehman, A. J. (1948) J. Nutr., 36. 15 Sollars, W. F. (1961) Cereal Chem., 38, 487
See Also: Toxicological Abbreviations Chlorine (ICSC) Chlorine (WHO Food Additives Series 20) CHLORINE (JECFA Evaluation) Chlorine (PIM 947)