WHO Pesticide Residues Series, No. 1



    The evaluations contained in these monographs were prepared by the
    Joint Meeting of the FAO Working Party of Experts on Pesticide
    Residues and the WHO Expert Committee on Pesticide Residues that met
    in Geneva from 22 to 29 November 1971.1

    World Health Organization



    1 Pesticide Residues in Food: Report of the 1971 Joint Meeting of
    the FAO Working Party of Experts on Pesticide Residues and the WHO
    Expert Committee on Pesticide Residues, Wld Hlth Org. techn. Rep.
    Ser., No. 502; FAO Agricultural Studies, 1972, No. 88.

    These monographs are also issued by the Food and Agriculture
    Organization of the United Nations, Rome, as document AGP-1971/M/9/1.

    FAO and WHO 1972


    This pesticide was previously evaluated at the Joint Meeting in 1965
    (FAO/WHO 1965c) and reviewed in 1967 (FAO/WHO 1968b). Very little new
    information on this pesticide has appeared since 1967. It was
    previously listed as ethylene dichloride.

    Reference should be made to Appendix IV. It contains Section 3 of the
    report on the 1971 meeting (FAO/WHO 1972a) where general principles
    relating to residues of fumigants are discussed; also the Appendix
    contains information on some commercially available mixtures of


    Use pattern

    Post-harvest use on dry foodstuffs

    1,2-dichloroethane has been widely used for many years, usually in
    admixture with carbon tetrachloride as a fumigant for bulks of raw
    cereals in bins or on floors. It is difficult to assess present world
    usage but this is probably much less than formerly.


    1,2-dichloroethane is physically sorbed by foods more strongly than
    carbon tetrachloride but less markedly than 1,2-dibromoethane. There
    is no available evidence of any reaction with the food constituents.
    Studies with the isotopically labelled fumigant have not been made and
    would probably be necessary to demonstrate any reaction, which, if
    occurring, must be very small in amount.

    The effect of processing to flour and broad has been studied by Wit et
    al., (1969). There were some discrepancies between the results
    reported by the different participating laboratories but the general
    picture emerged that, starting with grain which had been aired for
    several weeks after fumigation and which then contained 10 to 25 ppm
    of 1,2-dichloroethane, the amounts found in white flour are usually
    between 2 and 11 ppm and in bread were usually below 0.05 ppm.

    Methods of residue analysis

    Methods using gas-chromatography have now replaced earlier chemical
    methods. Heuser and Scudamore (1968) obtained satisfactory extraction
    of cereals and wheat flour by shaking at room temperature with a 5:1
    by volume acetone and water mixture. Aliquots of the supernatant
    liquid were injected into the gas-chromatograph and determined by a
    flame ionization detector. This procedure was developed by Heuser and
    Scudamore (1969) into a multi-residue scheme and it was found that a

    B-ionization detector gave the highest response to 1,2-dichloroethane
    giving a method which will determine 0.1 ppm.

    National tolerances (as reported to meeting)

    Australia, Canada and the United States of America all exempt ethylene
    dichloride from the requirement of a tolerance on the grounds that no
    hazard will remain when the food reaches the consumer.


    1,2-dichloroethane has been extensively used as a post-harvest
    fumigant for many years. It is usually applied in a mixture with
    carbon tetrachloride, with small proportions of other fumigants
    sometimes added. The main use is on bulks of raw cereals.
    1,2-dichloroethane is physically sorted on these foods but there is no
    evidence of any chemical breakdown or reaction. There is evidence of a
    substantial reduction in the amount of residual fumigant when the
    grain is milled and baked into bread. Analytical methods are available
    which will determine 0,1 ppm of 1,2-dichloroethane.

    There is a little direct information on the amounts of residual
    1,2-dichloroethane appearing in commercial samples or in food reaching
    the consumer. From the available information on the occurrence of
    unchanged 1,2-dichloroethane in or on raw cereals or cereal products
    after fumigation in accordance with good practice it appears that the
    following amounts need not be exceeded and it is recommended that
    these residue levels be used as guidelines:

         In raw cereals at point of entry into a country
         or when supplied for milling, provided that the
         commodity is freely exposed to air for a period
         of at least 24 hours after fumigation before
         sampling                                              50 ppm

         In milled cereal products which will be subjected
         to baking or cooking                                  10 ppm

         In bread and other cooked cereal products
         (i.e. at or about the present limit of
         determination)                                       0.1 ppm

    Further work desirable

    Additional data on residues of unchanged 1,2-dichloroethane occurring
    in food in commercial practice.


    Alumot, E. and Bieloria, R. (1969) Residues of fumigant mixture in
    cereals fumigated and aired at two different temperatures. J. Agric.
    Food Chem., 17: 869

    Bieloria, B. and Alumot, E. (1966) Determination of residues of a
    fumigant mixture in cereal grain by electron-capture
    gas-chromatography. J. Agric. Food Chem., 14: 622

    Conroy, M. W., Munsey, V. E. and Ramsey, L. L. (1957) Total volatile
    organic halide determination of aggregate residue of carbon
    tetrachloride, ethylene dichloride, and ethylene dibromide in
    fumigated cereal products. 2. Ethanolamine-sodium reduction procedure.
    J. Ass. Offic. Agr. Chem., 40: 185-189

    Heuser, S. G. and Scudamore, K. A. (1968b) Determination of residual
    acrylonitrile, carbon disulfide, carbon tetrachloride and ethylene
    dichloride after fumigation. Chem. and Ind., 1154-1157

    Heuser, S. G. and Scudamore, K. A. (1969) Determination of fumigant
    residues in cereals and other foodstuffs: a multidetection scheme for
    gas-chromatography of solvent extracts. J. Sci. Food Agric.,
    20: 565-572

    Heuser, S. G. and Scudamore, K. A. (1970) Selective determination of
    ionized bromide and organic bromides in foodstuffs by gas-liquid
    chromatography with special reference to fumigant residues. Pesticide
    Sci., 1: 244-249

    Heuser, S. G., Goodship, G. and Duffin, P. (1968) Residues of ethylene
    dibromide on samples of maize and prepared foods. Pest Infestation
    Research, 1968. Agricultural Research Council, London

    Lindgren, D. L., Gunther, F. A. and Vincent, L. E. (1962) Bromide
    residues in wheat and milled wheat fractions fumigated with methyl
    bromide. J. Econ. Entomol., 55: 773-776

    Lynn, G. E. and Vorkes, F. A. (1957) Symposium: Residues in foods and
    feeds resulting from fumigation of grains with the commoner liquid
    formulations of carbon disulfide, carbon tetrachloride, ethylene
    dichloride, and ethylene dibromide. J. Ass. Offic. Agr. Chem.,
    40: 163-209

    McMahon, B. Malone. (1971) Analysis of commercially fumigated grains
    for residues of organic fumigants. J. Ass. Offic. Chem., 54: 964-965

    Malone, B. (1969) Analysis of grains for multiple residues of organic
    fumigants. J. Ass. Offic. Analyt. Chem., 52: 800-805

    Malone, B. (1970) Method for determining multiple residues of organic
    fumigants in cereal grains. J. Ass. Offic. Analyt. Chem.,
    53: 742-746

    Wit, S. L., Besemer, A. F. H., Das, H, A., Goedkoop, W., Loosjes, F.
    E. and Meppelink, E. R. (1969) Results of an investigation on the
    regression of three fumigants (carbon tetrachlorine, ethylene
    dibromide and ethylene dichloride) in wheat during processing to
    bread. Report No. 36/69

    See Also:
       Toxicological Abbreviations
       Dichloroethane, 1,2- (EHC 176, 1995, 2nd edition)
       Dichloroethane, 1,2- (EHC 62, 1987, 1st edition)
       Dichloroethane, 1,2- (FAO Nutrition Meetings Report Series 48a)
       Dichloroethane, 1,2- (WHO Food Additives Series 30)
       Dichloroethane, 1,2- (Pesticide residues in food: 1979 evaluations)
       Dichloroethane, 1,2- (CICADS 1, 1998)
       Dichloroethane, 1,2- (IARC Summary & Evaluation, Volume 71, 1999)