NONANAL

    Explanation

         The biological data on nonanal were reviewed at the eleventh
    meeting of the Joint FAO/WHO Expert Committee on Food Additives,
    specifications were prepared, and a conditional acceptable daily
    intake (ADI) of 0-0.1 mg/kg bw was established (FAO/WHO, 1967;
    FAO/WHO, 1968).

         Since this previous review, new data have become available and
    are included in this summary.

    BIOLOGICAL DATA

    BIOCHEMICAL ASPECTS

         The several unsubstituted aliphatic aldehydes which have been
    studied (Hedlund & Kiessling, 1969), and presumably all others, are
    readily oxidized in the body to the corresponding fatty acids
    (Williams, 1959; F.E.M.A., 1974). Short and medium chain length fatty
    acids are oxidized primarily to CO2 and water (Scheig & Klatskin,
    1968). Such oxidation takes place rapidly both in the liver and other
    tissues (Geyer et al., 1951; Valdivieso & Schwabe, 1964). The series
    of reactions involved in the degradation of the fatty acid chain -
    including the odd-number carboxylic acids - have been fully described
    (Siegel, 1950; Deuel, 1957; Williams, 1959; Lehninger, 1970; F.E.M.A.,
    1974).

    TOXICOLOGICAL ASPECTS

    Acute toxicity

                                                               

                               LD50
    Animal       Route         ml/kg bw        References
                                                               

    Rat          oral          >5 000         Opdyke, 1973

    Rabbit       dermal        >5 000         Opdyke, 1973
                                                               

    Short-term studies

    Rat

         In a 12-week feeding study on groups of 12 male and 12 female
    weanling rats using a blend of six aliphatic aldehydes, providing an
    estimated daily intake for nonanal of 29 mg/kg bw (with a total daily
    intake for the blend of 112 mg/kg), no adverse effects were observed 

    in appearance, behaviour, growth, food consumption, efficiency of food
    utilization, presence of sugar or albumin in the urine, blood
    haemoglobin, liver and kidney weights, or gross pathology (Oser,
    1967).

    Comments

         Nonanal showed no adverse effects in the one available short-term
    study. The evaluation of nonanal (aldehyde C-9) is based on the
    presumed in vivo oxidation to the corresponding acid. A monograph
    was prepared.

         The previous conditional ADI was changed into a temporary ADI.

    EVALUATION

    Estimate of temporary acceptable daily intake for man

    0-0.06 mg/kg bw.

    FURTHER WORK OR INFORMATION

    Required by 1981.

         Adequate metabolic studies in several species.

    REFERENCES

    Deuel, H. J. jr (1957) The lipids, their chemistry and biochemistry.
         Chapter III in Biochemistry, Biosynthesis, Oxidation, Metabolism
         and Nutritional Value, New York, Interscience Publishers, Inc.

    FAO/WHO (1967) Toxicological evaluation of some flavouring substances
         and non-nutritive sweetening agents, FAO Nutrition Meetings
         Report Series No. 44a; WHO/Food Add./68.33

    FAO/WHO (1968) Specifications for the identity and purity of food
         additives and their toxicological evaluation: some flavouring
         substances and non-nutritive sweetening agents. Eleventh Report
         of the Joint FAO/WHO Expert Committee on Food Additives, FAO
         Nutrition Meetings Report Series No. 44; Wld Hlth Org. techn.
         Rep. Ser. No. 383

    F.E.M.A. (1974) Scientific literature review of aliphatic primary
         alcohols, aldehydes, esters, and acids in flavor usage.
         Published by the National Information Services under contract
         with the Food and Drug Administration

    Geyer, R. P. et al. (1951) Extrahepatic lipid oxidation by the rat,
         Fed. Proc., 10(1), 188-189

    Hedlund, S. G. & Kiessling, K. H. (1969a) Physiological mechanism
         involved in hangover. I. Oxidation of some lower aliphatic fusel
         alcohols and aldehydes in rat liver and their effect on the
         mitochondrial oxidation of various substrates, Acta Pharm.
         Toxicol., 27(5), 381-396

    Lehninger, A. L. (1970) Biochemistry, New York, Worth Publishers Inc.

    Opdyke, D. L. J. (1973) Fragrance raw materials monographs, Food
         Cosmet. Toxicol., 11, 115

    Oser, B. L. (1967) Unpublished report

    Scheig, R. & Klatskin, G. (1968a) Hepatic metabolism of 2-Cl4 octanoic
         and 1-Cl4 Palmitic acids. In: 40th Fall Meeting Program of the
         American Oil Chemists' Society: Symposium on medium chain
         triglycerides, 2-5 October 1966, J. Am. Oil Chem. Soc.,
         45(1), 31-33

    Siegel, I. (1950) Metabolism of N-valeric acid in the intact rat,
         Federation Proceedings

    Valdivieso, V. D. & Schwabe, A. D. (1964) Effect of exclusion of
         hepatic circulation on oxidation of octanoic acid in the rat,
         Proc. Soc. Exptl. Biol. Med., 116(2), 290-292

    Williams, R. T. (1959) Detoxication mechanisms, The metabolism and
         detoxication of drugs, toxic substances and other compounds,
         London, Chapman & Hall Ltd, 2nd ed.
    

    See Also:
       Toxicological Abbreviations
       Nonanal (FAO Nutrition Meetings Report Series 44a)
       NONANAL (JECFA Evaluation)