ETHYL VANILLIN 1. EXPLANATION Ethyl vanillin was evaluated at the eleventh meeting of the Committee (Annex 1, ref 14) when an Acceptable Daily Intake of 0-10 mg/kg bw was allocated to this compound. The eleventh meeting noted that few metabolic studies had been carried out on this compound and considered that further metabolic studies were desirable. Ethyl vanillin was placed on the agenda of the present meeting on the basis of partial application of the method for setting priorities for the safety review of food flavouring ingredients (Annex 1, reference 83). Since the last review, additional data have become available and are summarized and discussed in the following monograph. The previously published monograph has been expanded and is incorporated into this monograph. 2. BIOLOGICAL DATA 2.1 Biochemical aspects 2.1.1 Metabolism and Pharmacokinetics This compound is probably metabolized to glucuroethyl vanillin and ethyl vanillic acid, of which some is conjugated with glucuronic and sulfuric acids (Williams, 1959). 2.2 Toxicological studies 2.2.1 Acute toxicity Species Route LD50 Reference (mg/kg bw) Mouse i.p. 750 Caujolle & Meynier, 1954a Rat oral 1590 Sporn, 1960 oral >2000 Jenner et al., 1964 s.c. 1800 Deichmann & Kitzmuller, 1940 Guinea pig i.p. 1140 Caujolle & Meynier, 1954b Dog i.v. 760 Caujolle et al., 1953 * Maximum non-lethal dose, 450 mg/kg bw; LD50 = 950 mg/kg bw. A dose of 150 mg/kg bw caused no adverse effects and at 2500 mg/kg bw only a transient increase in respiration rate was observed when groups of 6 rabbits were given ethyl vanillin by oral gavage. The minimum oral lethal dose was reported to be 3000 mg/kg bw (Deichmann & Kitzmuller, 1940). 2.2.2 Short-term studies 2.2.2.1 Rats Doses of 300 mg/kg bw were administered to rats by gavage twice weekly for 14 weeks without any adverse effects. In another experiment, groups of 16 rats were fed 20 mg/kg bw daily for 18 weeks without adverse effect but 64 mg/kg bw daily for 10 weeks reduced growth rate and caused myocardial, renal, hepatic, lung, spleen and stomach injuries (Deichmann & Kitzmuller, 1940). Groups of male rats were fed 0, 2 or 5% ethyl vanillin in the diet for one year without any adverse effects (Hagan et al., 1967). Sixteen rats were given 30 mg ethyl vanillin weekly for 7 weeks without adverse effect on growth, food intake or protein utilization (Sporn, 1960). 2.2.2.2 Rabbits Single rabbits were given ethyl vanillin orally in 10% aqueous glycerine at doses of 15 mg/kg bw/day for 13 of 15 days, or 26 of 31 days, 32 mg/kg bw/day for 15 of 17 days, 41 mg/kg bw/day for 26 of 31 days or 49 mg/kg bw/day for 43 of 49 days. At the highest dose level, anaemia, diarrhoea and lack of weight gain were observed but no toxic signs were reported at any of the lower levels (Deichmann & Kitzmuller, 1940). 2.2.3 Long-term/carcinogenicity studies 2.2.3.1 Mice The maximum tolerated dose for ethyl vanillin in mice when administered i.p. 3 times per week for 2 weeks and tolerated through a subsequent 24 week observation period was reported to be 75 mg/kg bw. Administration of ethyl vanillin i.p. at doses of 15 or 75 mg/kg bw three times a week for eight weeks resulted in respective mortalities of 8/20 and 10/20 animals. Control animals receiving i.p. injections of the vehicle, tricaprylin, had survival rates of 77/80 (males) and 77/80 (females). In the control group, 28% of males and 23% of females developed lung tumours whereas in the treated groups only one animal, in the higher dose group, exhibited a single lung nodule. It was concluded that ethyl vanillin did not potentiate the pulmonary tumour responses in strain A mice (Stoner et al., 1973). 2.2.3.2 Rats Groups of 12 male and 12 female rats were fed diets containing 0, 0.5, 1 and 2% ethyl vanillin for 2 years or 2% and 5% for one year without any adverse effects on growth, organ weights of major organs, hematology and histology of major tissues (Hagan et al., 1967). 2.2.4 Reproduction studies No data available. 2.2.5 Special studies on mutagenicity Ethyl vanillin was negative in a mouse micronucleus assay when given to groups of four mice as two i.p. doses of up to 1 g/kg bw at an interval of 24 hours (Wild et al., 1983). Ethyl vanillin did not induce mutations in the Ames Salmonella/ microsome assay against Salmonella typhimurium strains TA92, TA1535, TA100, TA1537, TA94 and TA98, with or without metabolic activation using rat or hamster liver S9 fractions (Wild et al., 1983; Mortelmans et al., 1986). In in vitro assays using Chinese hamster ovary cells, ethyl vanillin did not induce chromosomal aberrations; the compound did cause an increase in polyploid cells but the significance of this is unclear and similar polyploidy was induced by riboflavin (Ishidate et al., 1984). Ethyl vanillin did not induce sister chromatid exchanges in cultured Chinese hamster ovary cells in vitro but was reported to enhance the ability of mitomycin C to cause sister chromatid exchanges (Sasaki et al., 1987). No heritable mutations were detected when ethyl vanillin was used in the BASC on Drosophila melanogaster (Wild et al., 1983). In a study on the anti-mutagenic potential of flavourings, ethyl vanillin was reported to show marked anti-mutagenic activity against mutagenicity induced by 4-nitroquinoline-1-oxide, furylfuramide, captan or methylglyoxal in Escherichia coli WP2s but was ineffective against mutations induced by Trp-P-2 or IQ in Salmonella typhimurium TA98. It was assumed that the anti-mutagenic activity was due to enhancement of an error-free recombinational repair system (Ohta et al., 1986). 2.3 Observations in man In a 24-hour closed patch test in 25 subjects, ethyl vanillin tested at 2% in petrolatum produced a mild irritation. No sensitization reactions were evoked when ethyl vanillin was used at 2% in petrolatum in a maximization test on 25 volunteers (Kligman, 1970). 3. COMMENTS The Committee noted that none of the previously evaluated long- term or carcinogenicity studies meet modern standards in that fewer animals per group had been used than would be the present norm. Accordingly the Committee reduced the previous ADI and made it temporary. 4. EVALUATION Level causing no toxicological effect Rat: 5000 ppm, equivalent to 250 mg/kg bw/day. Estimate of temporary acceptable daily intake 0-5 mg/kg bw. Further work required by 1992 1. An adequate short-term study in rats, and 2. metabolic studies in rats. 5. REFERENCES CAUJOLLE, F. & MEYNIER, D. (1954a). Toxicity of vanillin, o-vanillin and ethyl vanillin and of the corresponding meta aldehydes. Ann.Pharm.Fr., 12, 42-49. CAUJOLLE, F. & MEYNIER, D. (1954b). The comparative toxicities of orthovanillin and ethyl orthovanillin. Compt.Rend., 238, 2576-2578. CAUJOLLE, F., MEYNIER, D. & MOSCARELLA, C. (1953). The comparative toxicity of ethyl vanillin and 4-hydroxy-5-ethoxyisophthalic dialdehyde. Compt.Rend., 237,765-766. DEICHMANN, W. & KITZMULLER, K.V. (1940). Toxicity of vanillin and ethyl vanillin for rabbits and rats. J.Am.Pharm.Assoc., 29, 425-428. HAGAN, E.C., HANSEN, W.H., FITZHUGH, O.G., JENNER, P.M., JONES, W.I., TAYLOR, J.M., LONG, E.L., NELSON, A.A. & BROUWER, J.B. (1967). Food flavourings and compounds of related structure. II. Subacute and chronic toxicity. Fd Cosmet.Toxicol., 5, 141-157. ISHIDATE, M., SOFUNI, T., YOSHIKAWA, K., HAYASHI, M., NOHMI, T., SAWADA, M., & MATSUOKA. A. (1984). Primary mutagenicity screening of food additives currently used in Japan. Fd Chem.Toxicol., 22, 623-636. JENNER, P.M., HAGEN, E.C., TAYLOR, J.M., COOK, E.L. & FITZHUGH, O.G. (1964). Food flavourings and compounds of related structure. I. Acute oral toxicity. Fd Cosmet.Toxicol., 2, 327-343. KLIGMAN, A.M. (1970). Unpublished report to RIFM cited in Opdyke, D.L.J. (1975). Monographs on fragrance raw materials. Fd Cosmet.Toxicol., 13, 103-104. MORTELMANS, K. et al., (1986). Environ.Mutagen., 8, Suppl.7, 1. OHTA, T., WATANABE, M., WATANABE, K., SHIRASU, Y. & KADA, T. (1986). Inhibitory effects of flavourings on mutagenesis induced by chemicals in bacteria. Fd Chem.Toxicol., 24, 51-54. SASAKI, Y.F., IMANISHI, H., OHTA, T. & SHIRASU, Y. (1987). Effects of antimutagenic flavourings on SCEs induced by chemical mutagens in cultured Chinese hamster cells. Mutation Res., 189, 313-318. SPORN, A. (1960). Igiena (Bucharest), 9, 365. STONER, G.D., SHIMKIN, M.G., KNIAZEFF, A.J., WEISBURGER, J.H., WEISBURGER, E.K. & GORI, G.B. (1973). Test for carcinogenicity of food additives and chemotherapeutic agents by the pulmonary tumour response in strain A mice. Cancer Res., 33, 3069-3085. WILD, D., KING, M-T., GOCKE, E. & ECKHARDT , K. (1983). Study of artificial flavouring substances for mutagenicity in the salmonella/microsome, BASC and micronucleus tests. Fd Chem.Toxic., 21, 707-719. WILLIAMS, R.T. (1959). Detoxication Mechanisms, 2nd Edition, Chapman & Hall, London.
See Also: Toxicological Abbreviations Ethyl vanillin (FAO Nutrition Meetings Report Series 44a) Ethyl vanillin (WHO Food Additives Series 35) ETHYL VANILLIN (JECFA Evaluation)