DIMETHOATE JMPR 1977
Explanation
Dimethoate was evaluated by the Joint Meetings held in 1965 and 1966;
a complete revision was written in 1967, with an addendum in 1970
(FAO/WHO 1965, 1967, 1968, 1971). On the latter occasion, maximum
residue limits were recommended for residues of dimethoate in tree
fruits (2 mg/kg), tomatoes and peppers (1 mg/kg) and other vegetables
(2 mg/kg), the residues to be determined as dimethoate and omethoate
and expressed as dimethoate. (These levels had been recommended as
temporary limits in 1967.) At the 1973 Joint Meeting (FAO/ESTO 1974b),
the related compound formothion was reviewed and, as a result, maximum
residue limits for dimethoate were recommended for blackcurrants (2
mg/kg) and strawberries (2 mg/kg) to include residues resulting from
the use of either formothion or dimethoate on those crops.
Information received (Canada, 1976) has indicated that a maximum
residue limit of 0.3 mg/kg is inadequate to cover residues arising
from the use of dimethoate itself on strawberries at recommended
application rates (up to 1.3 kg a.i./ha) with a pre-harvest interval
of 7 days. The data summarized in Table 1 fully support this
contention.
RECOMMENDATION
The previous recommendation of 0.3 mg/kg on strawberries is amended as
follows. The limit is for the sum of dimethoate and omethoate
expressed as dimethoate.
Commodity Limit, mg/kg
Strawberries 1
REFERENCES
Canada (1976) Data provided by Canadian Government sources.
(unpublished).
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 (1976) Evaluation of some pesticide residues in food.
FAO:PL/CP/15; WHO/Food Add./67.32.
FAO/WHO (1968) 1976 evaluation of someyestioide residues in food.
FAO/PL:1967/M/11/1; WHO Food Add./68.30.
FAO/WHO (1971) 1970 evaluations of some pestioide residues in food.
AGP:1970/M/12/1; WHO Food Add./71.42.
TABLE 1. Residues of dimethoate and omethoate on strawberries treated in supervised trials.
Applications
Location Rate Pre-harvest Residues found (mg/kg)
(kg/a.i./ha) No. interval(days) Dimethoate Omethoate Total
California 1.1 3 0 1.08 0.06 1.14
3 0.89 0.05 0.94
7 0.58 0.03 0.61
13 0.33 0.03 0.36
Louisiana 1.1 3 0 2.89 0.05 2.94
3 2.71 0.05 2.76
7 1.09 0.02 1.11
14 0.29 0.09 0.38
Florida 1.1 4 0 0.29 0.03 0.32
3 0.27 0.01 0.28
8 0.01 0.01 0.02
14 0.06 0.02 0.08
N. Carolina 0.56 3 14 0.02 0.01 0.03
1.1 1 14 0.07 0.05 0.12
2 x 0.56 ) 0 1.26 0.05 1.31
+ 1 X 1.1 ) 3 3 0.86 0.10 0.96
7 0.34 0.10 0.44
14 0.01 0.00 0.01
2 x 1.1 ) 0 2.37 0.09 2.46
1 x 2.2 ) 3 3 1.49 0.16 1.65
7 0.83 0.17 1.00
14 0.09 0.06 0.15
New Jersey 0.56 4 0 0.47 0.00 0.47
7 0.16 0.00 0.16
14 0.17 0.08 0.25
See Also:
Toxicological Abbreviations