CHLOROBENZILATE JMPR 1977
Explanation
This compound has already been evaluated by the Joint Meeting in 1965,
1968, 1972 and 1975 (FAO/WHO, 1965, 1969, 1973, 1976). For the 1977
Joint Meeting, the principal manufacturer submitted data on the
possible carry-over of residues in grapes to wine and the
disappearance of chlorobenzilate in soil in response to the requests
of the 1972 Meeting.
RESIDUES IN FOOD AND THEIR EVALUATION
FATE OF RESIDUES
Disappearance in soil
Chlorobenzilate was applied to silty loam bare soil at 5 kg a.i./ha
and its disappearance was followed up to 210 days. Disappearance
of chlorobenzilate was rapid with a half-life of less than 30 days.
Vertical movement appeared confined to the upper 0-5 cm soil layer.
No residues were observed after 61 days. The concentration of the
metabolites 4,4'- dichlorobenzilic acid and 4,4'- dichlorobenzophenone
reached a maximum after 20 and 61 days, respectively, and rapidly
decreased thereafter.
Residues in grapes, yeast, and wine
White and red grapes were treated to run-off six weeks before harvest
with chlorobenzilate at the concentration of 0.04 a.i. At harvest,
residues of about 1.4 mg/kg and 2.8 mg/kg were found in white and red
grapes, respectively. After normal vinification, no residues were
detected in the white and red wine at a 0.05 mg/kg limit of
determination. The results show that even in the presence of residues
up to about 3 mg/kg in grapes, no carry-over into wine occurs. On
yeast, 0.13 mg/kg and 0.19 mg/kg residues were found in strains on
white and red grapes, respectively.
APPRAISAL
When chlorobenzilate was applied to a bare, silty loam soil at 5 kg
a.i./ha, disappearance was rapid with a half-life of less than 30
days and residues could not be detected after 61 days. Vertical
movement was confined to the upper 5 cm of soil. The concentration
of the metabolites 4,4' - dichlorobenzilic acid and
4,4' - dichlorobenzophenone reached a maximum after 20 and 61 days
respectively, and rapidly decreased thereafter.
When white and red grapes were treated until runoff six weeks before
harvest with a 0.04% a.i. solution, the residues at harvest were about
1.4 and 2.8 mg/kg in white and red grapes respectively. After normal
vinification, no residues could be detected in the white and red wines
(limit of determination 0.05 mg/kg). On yeast, 0.13 adn 0.19 mg/kg
residues were found from that of white and red grapes respectively.
The Meeting agreed that the information required by the 1972 Meeting
in respect of carry-over in wine and fate in soils had been supplied,
and provided reassurance that the residue limits previously
recommended were adequate. There was still a need for information on
the level and fate of residues in tea.
FURTHER WORK OR INFORMATION
Desirable
1. Information on the level and fate of chlorobenzilate residues in
tea.
REFERENCES
FAO/WHO (1965) Evaluation of the toxicity of pesticide residues in
food. FAO Meeting Report, No. PL:1965/10/1; WHO/Food Add./27.65.
FAO/WHO (1969) 1968 evaluations of some pesticide residues in food.
FAO/PL:1968/M/9/1; WHO/Food Add./69.35.
FAO/WHO (1973) 1972 evaluations of some pesticide residues in food.
AGP:1972/M/9/1; WHO Pesticide Residues Series, No. 2.
FAO/WHO (1970) 1975 evaluations of some pesticide residues in food.
AGP:1975/M/13; WHO Pesticide Residues Series, No. 5.