PESTICIDE RESIDUES IN FOOD - 1981
Sponsored jointly by FAO and WHO
EVALUATIONS 1981
Food and Agriculture Organization of the United Nations
Rome
FAO PLANT PRODUCTION AND PROTECTION PAPER 42
pesticide residues in food:
1981 evaluations
the monographs
data and recommendations
of the joint meeting
of the
FAO panel of experts on pesticide residues
in food and the environment
and the
WHO expert group on pesticide residues
Geneva, 23 November-2 December 1981
FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
Rome 1982
ACEPHATE
Explanation
Acephate was reviewed in 1976* and limits were recommended on a
variety of commodities. Some limits were revised in 1979. Additional
residue data on cabbage have been submitted to this Meeting and are
reviewed in this addendum, which should be considered along with
methamidophos reviewed elsewhere in these evaluations. The Meeting
also re-examined limits for potatoes, sugar beets and sugar beet
leaves at the request of the Codex Committee on Pesticide Residues.
RESIDUES IN FOOD
USE PATTERN
No additional national good agricultural practice information for
cabbage has been provided to the Meeting. The current 5 mg/kg limit
was based on a 14-day pre-harvest interval and presumably 1.0 kg
a.i./ha of unspecified formulations. Most of the residue data
submitted to this Meeting were from residue trials in one country, for
which multiple treatments at a label rate of 1.1 kg a.i./ha of Orthene
75S and a pre-harvest interval of 28 days is proposed. No good
agricultural practice information was available for the European
countries from which residue data were available. Therefore it could
not be determined whether the trials represent national good
agricultural practice.
RESIDUES RESULTING FROM SUPERVISED TRIALS
Residue data from field trials were available from four countries
and are summarized in Tables 1 and 2. Residue data in Table 1 were
available on the head and cap leaf and on the 7 inner and 4 outer
wrapper leaves, from which residues on the head plus wrapper leaves
were calculated based on the weight contribution and residue in each.
Average weights of the parts as a percentage of their sums were head
M-66%, seven inner leaves M-19%, and found outer leaves M-15%.
Residues levels of acephate and methamidophos in the inner and outer
leaves are summarized in Table 3.
Because of the degree to which cabbage might be trimmed in
practice varies with circumstances, data on the total head plus its
wrapper levels are the most important for estimating maximum residues.
This is also consistent with the portion of commodity to be analysed
specified by the Codex Committee on Pesticide Residues.
* See Annex II for FAO and WHO documentation.
TABLE 1. Residues of methamidophos (Ortho 9006) and acephate plus methamidophos (total in mg/kg) in cabbage treated with
acephate (75S formulation) from field trials in the United States 1
Test number 1 Head plus Head plus 2 Head plus 2
Location Number Days after cap leaf 7 inner wrappers 11 wrappers
Date of application of Kg a.i./ha last
Variety applications (litres) application ORTHO ORTHO ORTHO
9006 Total 9006 Total 9006 Total
0.04 0.24 0.15 1.1 0.26 2.5
T-2513 7 0.03 0.18 0.12 0.81 0.22 2.1
Iowa 0.04 0.20 0.09 0.48 0.17 1.2
10/73 9 1.12 14 0.03 0.16 0.08 0.39 0.16 1.3
Danish Ball Head (190) 0.04 0.15 0.05 0.26 0.10 0.66
21 0.03 0.13 0.07 0.30 0.13 1.0
0.04 0.13 0.08 0.25 0.12 0.53
28 0.03 0.12 0.07 0.27 0.13 0.75
0.03 0.15 0.12 0.71 0.22 1.5
T-2514 7 0.03 0.17 0.14 0.92 0.30 2.4
Iowa 1.12 0.03 0.14 0.06 0.30 0.12 0.70
9/73 5 (190) 14 0.03 0.16 0.09 0.48 0.19 1.5
Jersey Wakefield 0.00 0.05 0.00 0.09 0.01 0.23
21 0.00 0.04 0.01 0.07 0.01 0.15
0.06 0.34 0.29 2.2 0.43 4.0
T-2781 7 0.06 0.38 0.24 1.6 0.38 3.9
TABLE 1. (con't)
Test number 1 Head plus Head plus 2 Head plus 2
Location Number Days after cap leaf 7 inner wrappers 11 wrappers
Date of application of Kg a.i./ha last
Variety applications (litres) application ORTHO ORTHO ORTHO
9006 Total 9006 Total 9006 Total
Florida 0.06 0.32 0.35 2.1 0.46 3.5
11/73 6 1.12 14 0.07 0.37 0.28 1.8 0.42 3.3
Rio Verde (190) 0.05 0.22 0.18 1.2 0.32 2.0
21 0.05 0.22 0.22 1.1 0.33 2.0
0.06 0.21 0.18 0.73 0.28 1.4
28 0.05 0.19 0.16 0.65 0.27 1.4
0.06 0.28 0.18 1.4 0.32 3.3
T-2782 7 0.05 0.27 0.19 1.6 0.35 3.2
Florida 0.06 0.28 0.22 1.7 0.31 2.6
11/73 6 1.12 14 0.05 0.24 0.22 1.7 0.32 2.6
Keystone (50) 0.07 0.26 0.12 0.53 0.22 1.3
Red Head (190) 21 0.05 0.20 0.11 0.42 0.21 1.1
0.04 0.13 0.07 0.30 0.13 0.81
28 0.04 0.13 0.06 0.21 0.12 0.60
0.07 0.29 0.18 1.1 0.30 2.9
7 0.07 0.33 0.19 1.8 0.32 4.6
T-2783 0.07 0.25 0.21 1.1 0.33 2.0
Florida 14 0.08 0.31 0.23 1.4 0.33 2.7
TABLE 1. (con't)
Test number 1 Head plus Head plus 2 Head plus 2
Location Number Days after cap leaf 7 inner wrappers 11 wrappers
Date of application of Kg a.i./ha last
Variety applications (litres) application ORTHO ORTHO ORTHO
9006 Total 9006 Total 9006 Total
11/73 6 1.12 0.06 0.22 0.14 0.55 0.21 1.0
Savoy King (50) 21 0.07 0.29 0.18 0.81 0.26 1.7
(190) 0.04 0.11 0.07 0.22 0.10 0.47
28 0.05 0.14 0.08 0.27 0.13 0.82
0.07 0.34 0.30 1.6 0.44 3.2
7 0.06 0.30 0.23 1.7 0.35 3.3
T-2784 0.07 0.32 0.32 1.6 0.42 2.4
Florida 6 1.12 14 0.07 0.32 0.30 1.7 0.40 2.5
11/73 (50) 0.07 0.30 0.21 1.1 0.32 2.1
Abbot & Cobb (190) 21 0.08 0.34 0.22 1.3 0.33 2.3
No. 5 0.05 0.19 0.12 0.57 0.19 1.1
28 0.05 0.20 0.11 0.55 0.17 1.1
0.05 0.37 0.26 2.5 0.46 5.7
T-3162 5 1.12 8 0.04 0.28 0.262 2.3 0.392 3.52
New Jersey (95)
8/74
Greenback
TABLE 1. (con't)
Test number 1 Head plus Head plus 2 Head plus 2
Location Number Days after cap leaf 7 inner wrappers 11 wrappers
Date of application of Kg a.i./ha last
Variety applications (litres) application ORTHO ORTHO ORTHO
9006 Total 9006 Total 9006 Total
T-3470 0.07 0.32
Maryland 5 0.84 24 0.05 0.26
9/75 (95)
Early Round Dutch
1 Chevron, 1981
2 Calculated residues.
TABLE 2. Residues of acephate and methamidophos on acephate-treated cabbage resulting from European field trials
Residues (in mg/kg) at intervals (days)
Application after application
Country
Crop (Year) Rate Days
No. kg a.i./ha Formulation after last Methamidophos Acephate Ref 3
application
Cabbage France 1 0.45 75S 1 7 n.d. 0.06 TE-1296
(heads) (1974) (foliar) n.d. n.d.
n.d. n.d.
(1974) 3 0.45 50 s.p.1 7 n.d. n.d. TE-1300
n.d. 0.03
n.d. 0.05
Germany 2 3 2×0.25 50 s.p. 0 n.d.,0.03 0.14,1.0 TE-1498
(1976) 1×0.5 and
7 n.d, n.d. 0.02,0.03 TE-1500
10 n.d, n.d. 0.08,0.03
14 n.d., n.d. n.d.,0.03
21 n.d., n.d. n.d.,n.d.
1 soluble powder; 2 two separate trials; 3 Chevron, 1981.
TABLE 3. Summary residues of acephate and methamidophos in leaves of cabbage treated with acephate 1
7 inner leaves next 4 leaves
Days Acephate Acephate
after + + No. of
application Methamidophos Methamidophos Methamidophos Methamidophos samples
7 0.4-1.0 2-8 0.6-1.4 6-8 12
(0.6) (4.4) (1.0) (11)
14 0.2-1.2 0.9-7 0.5-1.4 3-9 12
(0.6) (3.6) (0.9) (8)
21 0.02-0.8 0.14-5 0.05-1.2 0.8-10 12
(0.4) (2.1) (.7) (5)
28 0.1-0.6 0.4-.3 0.3-1 2-7 10
(0.3) (1.3) (0.5) (3.8)
1 See also Table 1; mean residue in parentheses.
As can be seen in Table 1 the maximum residue of total acephate
plus methamidophos from proposed application rates and 28-day
pre-harvest interval is 1.4, and even at seven days it is in mg/kg
only 4 mg/kg. By difference, maximum residues of acephate per se
are, therefore, less than the current 5.0 mg/kg limit. The maximum
residue of methamidophos at any interval is 0.5 mg/kg and, therefore,
within the current 1.0 mg/kg limit for methamidophos. Overall,
residues of methamidophos are about 15% of the combined acephate plus
methamidophos residue.
As expected, Table 3 shows that residues on the outer leaves have
much higher residues (up to about 17 mg/kg acephate) than the whole
plant or trimmed head.
It can be seen in Table 2 that residues of acephate on cabbage
heads from the conditions of the European trials are well below the
current 5.0 mg/kg limit. These data are not as useful as they might
be, as it is not known whether these uses represent approved or
proposed good agricultural practices or whether they reflect those
that would result in maximum residues.
The analytical method used in the residue trials (RM - 12A) was
reviewed in 1976.
EVALUATION
APPRAISAL
The meeting examined residues data on cabbage from supervised
trials reflecting proposed good agricultural practices. From these
data the meeting concluded that there is no need to revise the current
5.0 mg/kg limit.
The Twelfth Session of CCPR requested the JMPR to reconsider
the assessments of the data on acephate in potatoes, sugar beet and
sugar beet leaves made in 1976. The meeting confirmed that the data
supported the proposal of 10 mg/kg for sugar beet leaves but
re-estimated the maximum residue levels in potatoes at 0.5 mg/kg
with an interval of 14 days (previously 1 mg/kg) with an interval of
3 days and in sugar beet at 0.1 mg/kg (previously 1 mg/kg). These
re-estimates are suitable for the establishment of revised limits.
FURTHER WORK OR INFORMATION
Desirable
Information on current good agricultural practices.
REFERENCES
Chevron Chemical Company. NOS. T-2513, T-2514, T-2781, T-2782, T-2783,
1981 T-2784, T-3162, T-3470, TE-1296, TE-1300, TE-1498 and TE-
1500. Submitted by Chevron Chemical Company to the 1981
Joint Meeting. (Unpublished)
See Also:
Toxicological Abbreviations
Acephate (ICSC)
Acephate (Pesticide residues in food: 1976 evaluations)
Acephate (Pesticide residues in food: 1979 evaluations)
Acephate (Pesticide residues in food: 1982 evaluations)
Acephate (Pesticide residues in food: 1984 evaluations)
Acephate (Pesticide residues in food: 1984 evaluations)
Acephate (Pesticide residues in food: 1987 evaluations Part II Toxicology)
Acephate (Pesticide residues in food: 1988 evaluations Part II Toxicology)
Acephate (Pesticide residues in food: 1990 evaluations Toxicology)
Acephate (JMPR Evaluations 2002 Part II Toxicological)
Acephate (JMPR Evaluations 2005 Part II Toxicological)