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

    CARBON TETRACHLORIDE

    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
    results of additional experimentation have become available and are
    summarized and discussed in the following monograph addendum.

    EVALUATION FOR TOLERANCES

    RESIDUES RESULTING FROM SUPERVISED TRIALS

    The sorption of carbon tetrachloride by cereals and cereal products is
    less than that of some other fumigants used in the mixtures (ethylene
    dichloride, ethylene dibromide). Increase of moisture content of wheat
    from 9.0 to 18.5 per cent did not increase the uptake of carbon
    tetrachloride. Even moderate decrease in particle size by grinding,
    very markedly increased the uptake of the gas (Berck, 1965a).

    Shelled walnuts, in 55-pound batches, were fumigated with 3 ml of a
    carbon tetrachloride-acrylonitrile mixture (34 : 66 by volume).
    Fumigation (3 hr) under reduced pressure, followed by storage for 30
    days resulted in carbon tetrachloride residues (5.3 ppm) which were
    lover than those (23.1 ppm) obtained by fumigation (48 hr) at
    atmospheric pressure. An aeration for four hours after fumigation at
    atmospheric pressure decreased the amount of carbon tetrachloride
    found to 9.6 ppm. At a dosage of 6 ml at atmospheric pressure (48 hr)
    33.7 ppm were found after 30 days storage (Berck, 1960).

    RESIDUES IN FOOD MOVING IN COMMERCE

    The Netherlands Government has analysed a number of imported cereals
    and has found that nearly half of the samples investigated (276
    samples from all over the world) contained a detectable amount of
    carbon tetrachloride. In about 20 per cent of all samples the residue
    range was 0.1 - 0.5 ppm, in 5 per cent the range was 0.5 -1 ppm, and
    in 8 per cent the range was 1 - 5 ppm. Three per cent of the samples
    investigated exceeded the 5 ppm level. The maximum residue found was
    58 ppm.

    METHODS OF RESIDUE ANALYSIS

    A polarographic method developed by Berck can be used for rapid
    measurement of carbon tetrachloride in amounts as low as 10-5M
    (Berck, 1962).

    Berck (1965b) also described a gas chromatographic multi-detection
    method for the determination of microgram amounts of 34 fumigant gases
    including carbon tetrachloride.

    An electron-capture gas chromatographic method for detecting carbon
    tetrachloride residues in the ppb range has been described (Bielorai
    and Alumot, 1966).

    NATIONAL TOLERANCES

    Country                Tolerance, ppm             Crop
                                                                  

    India                       5 ppm                 Cereals

    Netherlands                 0 ppm                 Grains

    U.S.A.                     exempt                 Barley, corn,
                                                      oats, popcorn,
                                                      rice, rye,
                                                      sorghum (milo),
                                                      wheat.
                                                                  

    RECOMMENDATIONS FOR TOLERANCES

    None recommended

    FURTHER WORK

    Further work required before recommendations for acceptable daily
    intakes and tolerances can be proposed. (See FAO/WHO, 1965)

    1.   Further investigation of the amount of the residual carbon
         tetrachloride remaining in the food after treatment and the
         effect on this of processing and cooking.

    2.   Long-term feeding studies should be carried out on two mammalian
         species.

    REFERENCES PERTINENT TO EVALUATION FOR TOLERANCES

    Berck, B. (1960) Retention of acrylonitrile and carbon tetrachloride
    by shelled walnuts fumigated with acrylon. J. Agr. Food Chem. 8:
    128-131.

    Berck, B. (1962) Polarographic determination of methyl bromide,
    ethylene dibromide, acrylonitrile, chloropicrin and carbon
    tetrachloride in air. J. Agr. Food Chem. 10 : 158-162.

    Berck, B. (1965a) Sorption of ethylene dibromide, ethylene dichloride
    and carbon tetrachloride by cereal products. J. Agr. Food Chem. 13 :
    248-254.

    Berck, B. (1965b) Determination of fumigant gases by gas
    chromatography. J. Agr. Food Chem. 13 : 373-377.

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

    FAO/WHO. (1965) Evaluation of the hazards to consumers resulting from
    the use of fumigants in the protection of food. FAO Mtg. Rept.
    PL/1965/10/2; WHO/Food Add./28.65.
    

    See Also:
       Toxicological Abbreviations
       Carbon Tetrachloride (EHC 208, 1999)
       Carbon Tetrachloride (HSG 108, 1998)
       Carbon tetrachloride (ICSC)
       Carbon tetrachloride (FAO Meeting Report PL/1965/10/2)
       Carbon tetrachloride (FAO/PL:1968/M/9/1)
       Carbon tetrachloride (WHO Pesticide Residues Series 1)
       Carbon tetrachloride (Pesticide residues in food: 1979 evaluations)
       Carbon Tetrachloride (IARC Summary & Evaluation, Volume 71, 1999)