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    FAO/PL:1967/M/11/1
    WHO/Food Add./68.30

    1967 EVALUATIONS OF SOME PESTICIDE RESIDUES IN FOOD

    THE MONOGRAPHS

    The content of this document is the result of the deliberations of the
    Joint Meeting of the FAO Working Party of Experts and the WHO Expert
    Committee on Pesticide Residues, which met in Rome, 4 - 11 December,
    1967. (FAO/WHO, 1968)

    FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
    WORLD HEALTH ORGANIZATION
    Rome, 1968

    ETHYLENE DICHLORIDE

    This pesticide was evaluated by the 1965 Joint Meeting of the FAO
    Committee on Pesticides in Agriculture and the WHO Expert Committee on
    Pesticide Residues (FAO/WHO, 1965). Since the previous publication,
    the available information pertinent to evaluations for tolerances has
    been restudied and is summarized and discussed in the following
    monograph addendum.

    EVALUATION FOR TOLERANCES

    USE PATTERN

    Pre-harvest treatments

    Ethylene dichloride, formulated with carbon tetrachloride, is
    sometimes used on the trunks and lower branches of fruit trees to
    control the peach tree borer. It is not used on any growing, edible
    part of a tree. Therefore, no ethylene dichloride residues result in
    foods from any known pre-harvest use.

    Post-harvest treatments

    A 3:1 ethylene dichloride-carbon tetrachloride mixture is commonly
    used as a fumigant for grain, pulses, and animal feeds. It is applied
    to these commodities while they are in bulk storage bins or under
    gasproof covers. The mixture is used at the rate of 2 to 6.5 gal/1,000
    bu (0.2 to 0.7 l/m3), depending on the product being treated and the
    type of enclosure.

    Other uses

    It is occasionally used for fumigating household articles such as
    clothing, rugs, upholstery, etc.

    RESIDUES RESULTING FROM SUPERVISED TRIALS

    Winteringham (1944a) found that sorption of ethylene dichloride by
    flour reached equilibrium within 24 hours, but sorption by whole wheat
    still continued after 1 week. In another study (1944b), he concluded
    that the retention of ethylene dichloride by wheat is physical and
    that there in no chemical decomposition of the fumigant within the
    product.

    Maximum residues on wheat obtained from fumigation with ethylene
    dichloride (35 per cent) in combination with carbon tetrachloride (60
    per cent) and ethylene dibromide (5 per cent) at the recommended
    dosage (2 gal/1,000 bu) (0.2 l/m3) and at triple the dosage were 55
    and 140 ppm of ethylene dichloride, respectively (Conroy, Walkden, and
    Farrell, 1957).

    Wheat treated with a mixture of carbon tetrachloride, ethylene
    dichloride, and ethylene dibromide (60:35:5 per cent by volume) at the
    normal dosage had 76 ppm of organic chloride in the wheat and 17, 22,
    and 58 ppm of ethylene dichloride in the flour, shorts, and bran,
    respectively (Munsey, 1957).

    RESIDUES IN FOOD MOVING IN COMMERCE

    Analyses conducted by The Netherlands during 1964-1965 period (CCPR,
    1966) showed that 4 out of 227 lots of cereal sampled, or 1.6 per cent
    of those imported, had ethylene dichloride present. The origin of the
    cereals with ethylene dichloride residues and the amounts found were:

                        United States             5   ppm

                        Argentina                 1.4 ppm
                                                 70   ppm
                                                 70   ppm

    FATE OF RESIDUES

    In storage and processing

    After wheat containing 140 ppm of ethylene dichloride was cleaned and
    tempered, the residue fell to 41 ppm. Wheat with 34.6 ppm of ethylene
    dichloride had 17.8 ppm after cleaning and tempering, and residues in
    the fractions after milling were 3 ppm in the flour, 3.5 ppm in the
    shorts, 22.8 ppm in the bran, and 12.0 ppm in the germ (Conroy,
    Walkden, and Farrell, 1957).

    Five bins of wheat fumigated with a carbon tetrachloride-ethylene
    dichloride mixture had 418 ppm of ethylene dichloride, 24 hours after
    fumigation, 325 ppm after the first turning (transfer to another bin),
    and 263 ppm after the third turning (Stenger and Mapes, 1957).

    Ethylene dichloride was added to flour at 6.1 and 40 ppm, the flour
    made into bread dough, and the dough then baked. The bread made from
    the two batches had less than 2 ppm of ethylene dichloride. Oats with
    61.6 ppm of ethylene dichloride had an average of 31.4 ppm after
    cooking (1 min) or a loss of 49 per cent (Munsey, Mills, and Klein,
    1957).

    When ethylene dichloride at levels up to 1,000 ppm was added to grain
    and was fed to cows, an average of less than 0.25 ppm was found in the
    milk. There appeared to be no direct correlation between the amounts
    of ethylene dichloride added to the grain and that found in the milk
    (Sykes and Klein, 1957)

    When 140 pounds (63.5 kg) of 85-per cent extracted wheat flour was
    fumigated for 48 hours at 25C with 300 g of ethylene dichloride (11.1
    lb/ton), samples from the center of the bag had 1,030 ppm, 350 ppm,
    and 46 ppm after airing 1 hour, 2 days, and 7 days, respectively (Pest
    Infestation Laboratory, 1943).

    METHODS OF RESIDUE ANALYSIS

    Ethylene dichloride residues have been determined by the combined
    methods of Ramsey (1957) which measures the carbon tetrachloride and
    of Conroy, Munsey, and Ramsey (1957) which measures the total organic
    halides. The amount of ethylene dichloride is calculated by
    subtracting the amount of carbon tetrachloride from the total
    inorganic halides. The sensitivity is 0.5 ppm.

    An electron-capture gas chromatographic method for detecting certain
    chlorinated residues in the ppb range has been described by Bielorai
    and Alumot (1966). This method may be adapted for ethylene dichloride
    residue analysis.

    NATIONAL TOLERANCES
                                                            

    Country                   Tolerances              Crop
                                                            

    Canada                    Exempt                  Grain

    United States             Exempt1/                Grain
                                                            

    1/According to U.S. Food and Drug laws, ethylene dichloride is
    exempt from requirement of a residue tolerance because when used as
    a fumigant for grain under currently prevailing practices it does not
    appear to involve any hazard to public health.

    RECOMMENDATIONS FOR TOLERANCES

    Cereals fumigated with ethylene dichloride according to good
    agricultural practices may contain high levels of the fumigant for a
    relatively long time. Aeration, aging, and processing will remove most
    of the ethylene dichloride but very small amounts may persist in the
    food. Since no reaction products or metabolites of ethylene dichloride
    have been found in grain, (IUPAC, 1967), the concern is over the
    amount of the ethylene dichloride per se present in the food when it
    reaches the consumer. No suitable analytical method is available for
    the specific determination of this fumigant. Furthermore no acceptable
    daily intake (ADI) could be estimated at this time with the available
    toxicological data.

    Under the above conditions, no tolerances were recommended for
    ethylene dichloride.

    FURTHER WORK

    Further work required before acceptable daily intakes and tolerances
    can be recommended

    In addition to that specified in the previous publication (FAO/WHO,
    1965) further data is required on:

    Extent of use as a fumigant for raw and processed foods.

    Residue levels in various food resulting from good agricultural
    practices and the effects of aerating, aging, processing, and cooking
    in reducing residues of ethylene dichloride.

    Development of a specific method for detecting ethylene dichloride
    with a sensitivity of about .001 ppm.

    Residue levels of ethylene dichloride in various types of food while
    in trade channels.

    REFERENCES PERTINENT TO EVALUATION FOR TOLERANCES

    Bielorai, R. and Alumot, E. (1966) Determination of residues of
    fumigant mixture in cereal grain by electron-capture gas
    chromatography. J. Agric. Fd. Chem., 14(6) : 622-625.

    CCPR. (1966) Codex Committee on Pesticide Residues. Residues of
    insecticides in cereals, imported in the Netherlands, 1964/65, Second
    Report. Paper prepared by the Ministry of Social Affairs and Public
    Health, Ministry of Agriculture. CCPR 66-17.

    Conroy, H.W., Munsey, V.E., and Ramsey, L.L. (1957) Residues foods and
    foods resulting from fumigation of grains with the commoner liquid
    formulations of carbon disulfide, carbon tetrachloride, ethylene
    dichloride, and ethylene dibromide. 2. Ethanolamine-sodium reduction
    procedure. J. Ass. Off. Agric. Chem., 40 (1) 9 185-189.

    Conroy, H.W., Walkden, H.H., and Farrell, E. (1957) The fumigation,
    milling, and sampling of wheat and its milled products. B. Manhattan
    studies. J. Ass. Off. Agric. Chem., 40 (1) : 166-168, 192-195.

    FAO/WHO. (1965) Evaluation of the hazards to consumers resulting from
    the use of fumigants in the protection of food. FAO Mtg. Rept. No.
    PL/1965/10/2; WHO/Food Add./28.65.

    IUPAC. (1967) International Union of Pure and Applied Chemistry.
    Proceedings of the Commission on Terminal Residues and the Commission
    on Residue Analysis. Vienna, August, 1967.

    Munsey, V.E. (1957) The fumigation, milling and sampling of wheat and
    its milled products. J. Ass. Off. Agric. Chem., 40(1) : 165, 192.

    Munsey, V.E., Mills, P.A., and Klein A.K. (1957) Effects of cooking on
    fumigated residues. J. Ass. Off. Agric. Chem., 40(1) : 201-202.

    Pest Infestation Laboratory. (1943) Pest Infestation Research Report :
    87. Slough, England.

    Ramsay, L.L. (1957) 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. B. Colorimetric determination of carbon tetrachloride in
    fumigated cereal products. J. Ass. Off. Agric. Chem., 40(1) : 175-180.

    Stenger, V.A. and Mapes, D.A. (1957) Effect of baking on ethylene
    dibromide and total bromide residues. J. Ass. Off. Agric. Chem.,
    40(1): 196-200.

    Sykes, J.F. and Klein, A.K. (1957) Chloro-organic residues in milk of
    cows orally administered ethylene dichloride. J. Ass. Off. Agric.
    Chem., 40(1) : 203-206.

    Winteringham, F.P.W. (1944a) The sorption of ethylene dichloride by
    wheat products. J. Soc. Chem. Ind., 63 : 144-150.

    Winteringham, F.P.W. (1944b) The sorption of ethylene dichloride by
    wheat products. J. Soc. Chem. Ind., 63 : 359-363.
    


    See Also:
       Toxicological Abbreviations
       Ethylene dichloride (FAO Meeting Report PL/1965/10/2)