FAO/PL:1968/M/9/1
WHO/FOOD ADD./69.35
1968 EVALUATIONS OF SOME PESTICIDE RESIDUES IN FOOD
THE MONOGRAPHS
Issued jointly by FAO and WHO
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 Geneva, 9-16 December,
1968.
FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
WORLD HEALTH ORGANIZATION
Geneva, 1969
CARBARYL
Since the previous evaluation (FAO/WHO, 1967), additional data have
become available and are summarized and discussed in the following
monograph addendum.
RESIDUES IN FOOD AND THEIR EVALUATION
Background
At the Third Session of the Codex Committee on Pesticide Residues, the
delegation of Australia requested the Joint Meeting to consider the
advisability of recommending tolerances in meat, milk products and raw
cereals, and subsequently furnished supporting data. Additionally, the
Codex Committee on Cocoa Products and Chocolate requested the Joint
Meeting to consider the advisability of recommending tolerances in
cocoa beans and derived products, and provided some background
information.
Use pattern
Carbaryl is used on cattle especially for the control of flies,
sand-flies, mosquitos, ticks and lice, some of which are vectors of
disease. It is used as an 0.5 per cent spray to control insects
attacking small grain crops.
Residues resulting from supervised trials
Claborn et al. (1963) ran experiments in which cattle, sheep, goats
and hogs were sprayed four times in two weeks with a 1.0 per cent
suspension of carbaryl, and Hereford steers were fed 50 and 200 ppm of
carbaryl in the diet for a period of 27 days. No residues were
detected in tissues of cattle fed carbaryl; however, some residues
were found in sprayed animals. Cattle fat had residues up to 0.57 ppm
one day after a spray application of 1.0 per cent carbaryl. Cattle
muscle tissue contained up to 0.13 ppm at one day and none at seven
days following the spray application. Sprayed sheep and goats
contained up to 0.38 in fat and 0.18 in muscle at one day. Goat brain
contained 23.0 ppm, whereas brain of cattle and sheep had 0.1 and 0.15
ppm respectively. No residue was found in hogs from the spray
application. Gyrisco et al. (1960) fed up to 450 ppm for two weeks and
found no residue in milk by a colorimetric method.
Dorough (1967) and Baron et al. (1968) fed radio-labelled carbaryl to
lactating cows and found very small amounts of radioactivity in milk
which was proved to be not from carbaryl. Baron et al. (1968) found
that the radioactivity was incorporated into the lactose of milk
(1968).
Hurwood (1967) sprayed cattle with carbaryl and samples of fat,
muscle, liver and kidney were taken from animals slaughtered one,
three or seven days after single or multiple treatments. Up to 0.17
ppm was found at one day and none at seven days from the single
application, but up to 0.92 was found from three applications applied
at two-day intervals and then allowing one day before slaughter. None
was found at seven days. In the pre-slaughter period this same study
showed about 0.5-1 ppm in butterfat and none in the aqueous phase.
However, full details of the separation of the butterfat from whole
milk were not available to the meeting. Further information on the
residue content of whole milk is required.
Limited residue studies from the application of 1.26 to 2.52 kg/ha on
oats, wheat and rye showed residues of 1 ppm on grain at 0 days and
13-49 ppm on straw at 0 days. These residues diminished to 0.3 at 28
days (one analysis) on grain, and 0.6 on straw (one analysis) at 28
days. The recommended usage prohibits application after the boot stage
(when the head begins to form, but before the spike emerges), which is
35 to 50 days before harvest. It is concluded that no residue
detectable by the available method of analysis would be present under
such conditions. No other data on cereals were available on different
rates of application, harvest period and the resultant residues at
various time intervals.
No data were available on residues in cocoa and cocoa products.
National tolerances
Country Crop Tolerance (ppm)
United States meat 5
of America poultry (fat basis) 5
cereals 0
RECOMMENDATIONS FOR TOLERANCES AND PRACTICAL RESIDUE LIMITS
Appraisal
There is no conclusive proof that any residue of carbaryl or
1-naphthol appears in meat when cattle are fed levels up to 200 ppm in
the diet. In cattle fed up to 450 ppm for two weeks no residues were
found in milk using a colorimetric method. The data available from use
of radioactive carbaryl indicate small amounts of "carbaryl
equivalents" but these do not respond to the colorimetric method.
However, there were residues up to 0.57 ppm one day after a spray
application of 1.0 per cent carbaryl.
Since the solubility of carbaryl is such that residues are likely to
be distributed between fat and the aqueous phases, it is proposed that
any residues in animal products be expressed on the whole product
rather than on a fat basis.
Recommendations
In addition to the previously recommended temporary tolerances to be
in effect until 1970:
Tree fruit including citrus fruit,
small fruit and berries, leafy
vegetables, brassica, olives,
shelled nuts, cucurbits, melons 10 ppm
Other vegetables, poultry,
cotton seed 5 ppm
Rice 2.5 ppm
The meeting also recommends the following temporary tolerances to be
in effect until 1970:
Meat of cattle, goat and sheep 1.0 ppm
Whole milk 0.02 ppm
The above temporary tolerances are to apply to raw agricultural
products moving in commerce unless otherwise indicated. In the case of
fruit and vegetables, the tolerances should be applied as soon as
practicable after harvest and in any event prior to actual retail to
the public. In the case of commodities entering international trade,
the tolerances should be applied by the importing country at the point
of entry or as soon as practicable thereafter.
Further work or information
Required before 30 June 1970
1. Further data on residue levels in whole milk.
2. Data on the required rates and frequencies of application,
pre-harvest or withholding intervals, and the resultant residues
under Australian conditions and conditions in other countries.
3. Data on the disappearance of residues during storage and processing
of cocoa beans and derived products.
4. Data on the disappearance of residues during storage and processing
of cereals into cereal products.
REFERENCES
Baron, R. L. et al. (1968) Confirmatory isolation and identification
of a metabolite of carbaryl in urine and milk (In press)
Claborn, H. V., Roberts, R. H., Mann, H. D., Bowman, H. C., Ivey, M.
C., Weidenbach, C. P. and Radeleff, R. D. (1963) Residues in body
tissues of livestock sprayed with Sevin or Sevin in the diet. J. Agr.
Food Chem., 11: 74-76
Dorough, H. W. (1967) Carbaryl-C14 metabolism in a lactating cow.
J. Agr. Food Chem., 15: 261-266
Gyrisco, G. C., Lisk D. J., Fertig, S. N., Huddleston, E. W., Fox, F.
H., Holland, R. F., Trimberger, G. W. (1960) The effects of feeding
high levels of Sevin on residue, flavour and odour of the milk of
dairy cattle. J. Agr. Food Chem., 8: 409-410
Hurwood, I. S. (1967) Studies on pesticide residues. 2. Carbaryl
residues in the body tissues and milk of cattle following dermal
application. Queensland Journal of Agricultural and Animal Sciences,
24: 69-74