PESTICIDE RESIDUES IN FOOD - 1984
Sponsored jointly by FAO and WHO
EVALUATIONS 1984
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
Rome, 24 September - 3 October 1984
Food and Agriculture Organization of the United Nations
Rome 1985
ACEPHATE
Explanation
Acephate was first reviewed by the 1976 JMPR 1/, at which time
residue limits were recommended on a variety of commodities.
Additional MRLs or revisions were made in 1979 and 1981 on the basis
of additional information. Toxicological aspects were also examined
again in 1982.
On several occasions the CCPR has requested the JMPR to consider
acephate and methamidophos MRLs and the relation between them, most
recently at its 16th Session.
Since 1976 the JMPR has estimated separate limits for acephate
and methamidophos to accommodate the use of either as a pesticide.
Since 1979 the JMPR has sought to estimate additional methamidophos
limits, or revise existing ones, to accommodate methamidophos residues
resulting from the use of acephate. There are currently methamidophos
limits for all crops in the Codex system for which there are acephate
limits, as well as methamidophos limits for some crops on which
apparently only methamidophos is used. In some cases the methamidophos
limits are intended to accommodate only acephate uses. Although
residue data and good agricultural practice information have never
been sufficient to define fully the relation between acephate and
methamidophos uses, the existing limits are intended to accommodate
GAP as far as possible. This evaluation considers additional
information which has been provided (see also methamidophos elsewhere
in these evaluations).
RESIDUES IN FOOD AND THEIR EVALUATION
USE PATTERN
Additional good agricultural practice information which was
provided is shown in Table 1.
Table 1. Use patterns of methamidophos
Application Interval between
Country and crop Formulation rate last application
(kg a.i./ha) and harvest, days
Canada
All uses are
non-food uses.
New Zealand 2/
Brassica vegetables 75% WP 0.75-1.0 7
Citrus " 75 g a.i./100 1 14
Potatoes " 0.75 7
Lettuce " 0.75 3
Tamarillos " 75 g a.i./100 1 14
Tobacco " 0.75 -
Tomatoes " 0.75 3
1/ See Annex 2 for FAO and WHO documentation
2/ Replaces 1976 submission
RESIDUES RESULTING FROM SUPERVISED TRIALS
Residues resulting from New Zealand field trials are summarized
in Table 2 (New Zealand, 1984).
Apples, pears, avocados, boysenberries. The limited residue data
(without good agricultural practice information) provided to this
meeting are insufficient to support a limit.
Cabbage. On several occasions the JMPR has been requested to
consider lowering the 5 mg/kg MRL. Substantial residue data were
provided to the 1981 JMPR to supplement data reviewed earlier, but
without information on GAP. The 1981 meeting concluded that there was
no basis for lowering the limits. Information on GAP and limited new
residue data were provided to the present meeting from New Zealand.
The single value at the approved 7-day pre-harvest interval was 0.8
mg/kg acephate, but this gives no reasons to lower the MRL, especially
in view of the 1981 JMPR data from the U.S.A. (with no approved use on
cabbage) which indicate that residues approaching 5 mg/kg at 7 days
can result from application rates similar to the rate considered good
agricultural practice in New Zealand. Even with the outer wrapper
leaves removed, the U.S. data would require a 2 mg/kg limit at 7 days.
Additional residue data and information on GAP are needed, including
GAP for those European countries which have already provided some
residue data.
Lettuce. The 5 mg/kg limit estimated by the 1979 JMPR is more than
adequate to accommodate the residue of 2.1 mg/kg found at 3 days
(reflecting good agricultural practice in New Zealand) reported to
this meeting. The meeting noted that the CCPR had retained the
original 1976 JMPR estimate of 10 mg/kg.
Citrus fruit. New Zealand data reviewed by the 1976 JMPR, with data
on one additional sample (Table 2), were re-evaluated in the light of
current GAP in that country. Maximum residues in the whole fruit
(calculated from peel and pulp residues) of approximately
3 mg/kg at the recommended 8-day interval support the current mg/kg
limit.
Potatoes. Limited additional residue data, together with
information on GAP (7-day pre-harvest interval) in New Zealand, do not
require a change in the 0.5 mg/kg limit established by the 1981 JMPR
for a 14-day pre-harvest interval. The original 1 mg/kg limit
estimated by the 1976 JMPR was based on a 3-day interval.
Tree tomatoes (tamarillos). Data were available from four trials
with a maximum residue of 0.46 mg/kg at the recommended 14-day
interval and application rates reflecting good agricultural practice
in New Zealand.
Tomatoes. The maximum residue was 0.2 mg/kg at the 3-day interval
recommended in New Zealand. There is no basis for revising the current
5 mg/kg limit.
EVIDENCE OF RESIDUES IN FOOD IN COMMERCE OR AT CONSUMPTION
Information was available on acephate residues in cucumbers,
mushrooms and pears from the monitoring of domestic and imported
samples in Sweden for the period January 1, 1981 to December 12, 1983
(Table 3; Bergman, 1984). No limits have been estimated by the JMPR
for these commodities.
NATIONAL MAXIMUM RESIDUE LIMITS
The following MRLs of New Zealand were reported to the meeting.
MRL, mg/kg
Brassica vegetables 2
Citrus 5
Tamarillos 0.5
Fruiting vegetables 1
Leafy vegetables 6
Table 2. Residues of acephate and methamidophos resulting from supervised field trials with acephate in New Zealand.
Application Residues, mg/kg
Crop Year
rate
No. kg a.i./ha Interval, acephate methamidophos New Zealand
(g a.i./100 1) formulation days Report
Apples 1971 5 2.5 75WP 13 0.63 0.04 PB 2041
(report (75) registered
date)
whole flesh PB 7/3/5
April 1980
Avocados 1970-80 6 0.125 " 0 1.8 0.68
(50) 7 1.5 0.56
14 0.24 0.26 PB 7/3/3
28 0.09 0.11 Feb. 1982
Boysen 1980 2-5 1.5 " 0 26.2 PB 7/3/3
berries (75) 1 26
3 26.5
20
4 19.6
5 15.9
7 22
14.6
9 18.2
13 8.7
18 4.6
21 2.5
Table 2. (continued)
Application Residues, mg/kg
Crop Year
rate
No. kg a.i./ha Interval, acephate methamidophos New Zealand
(g a.i./100 1) formulation days Report
Cabbage 1972-73 3 0.84 75 WP 0 0.6 0.13 PB/2041
registered 3 1.2 0.24 June 1973
7 0.8 0.17 and
Feb. 1972
1 1.1 " 10 1.2 0.2
3 0.84 " 16 <0.4 0.08
23 <0.4 0.05
1971 1 0.6-1.7 " 49-50 0.2 0.04
0.16 0.06
0.12 <0.01
Lettuce 1978 2 1 75 WP 0 2.5 PB 2041
(whole (116) registered 1 6.6 May 1979
head) 3 2.1
7 <0.1
10 0.6
14 0.2
Oranges 1973 9 (75) " 26 1.6 0.16
Pears ? 6 5 75 WP
(report (112) registered 43 0.47 0.07 PB/24041
1972 Feb. 1972
Table 2. (continued)
Application Residues, mg/kg
Crop Year
rate
No. kg a.i./ha Interval, acephate methamidophos New Zealand
(g a.i./100 1) formulation days Report
Potatoes 1973 3-5 0.42- " 4 <0.05 <0.05 PR/2041
0.84 June 1973
(50-136)
Tree 1982 8 (75) " 0 0.47 0.005 PB 7/3/14
tomatoes 1 0.31 0.005 June 1983
(Tamarillos ) 3 0.12 -
8 0.16 0.003
14 0.19 0.005
21 0.15 0.005
1981 7 4.2 " 0 0.82
(75) 1 0.94
3 0.60
7 0.39
14 0.46
20 0.40
28 0.28
Tamarillos 1982 10 3.75 75 WP 1 0.57 0.009
(75) registered 3 0.21 0.009 PB 7/3/2
7 0.28 0.009 June 1983
14 0.35 0.012
22 0.18 0.005
28 0.17 0.009
1977 5 (50) " 56 0.17 - PB 7/3/14
Oct. 1977
Table 2. (continued)
Application Residues, mg/kg
Crop Year
rate
No. kg a.i./ha Interval, acephate methamidophos New Zealand
(g a.i./100 1) formulation days Report
Tomatoes 1978 3-4 1 " 0 0.33 - PB/2041
(66.7) 1 0.61 - May 1979
3 0.19 -
7 0.20, 0.93 -
10 0.14 -
16 0.13 -
Table 3. Domestic and import monitoring of acephate in selected
commodities (1981-1983)
No. of samples
Food Origin No. of within given range (mg/kg)
samples < 1.01 1.01 - 2.53
Cucumber Sweden 312 312
Imported 416 411 5
Mushroom Sweden 28 28
Imported 18 17 1
Pear Sweden 151 150
Imported 515 515 1
APPRAISAL
The JMPR has on several occasions been requested to consider
acephate and methamidophos together in the light of their
relationship. There has never been sufficient information to do this
and that is still the case. Separate limits have been estimated for
the two compounds. Methamidophos limits have been proposed for all
crops for which there are acephate limits and some methamidophos
limits have been estimated to cover the use of methamidophos alone.
In the case of animals, acephate limits of 0.1 mg/kg have
previously been estimated for the meat and fat of cattle and pigs,
milk, eggs and poultry on the basis of feeding trials with acephate
plus methamidophos. No acephate limits have been estimated for sheep
or goats, for which there are methamidophos limits.
Some good agricultural practice information and supervised trials
residue data were available to the present meeting from one country.
Data were insufficient to estimate limits for apples, avocados or
boysenberries and there was no information on GAP for these
commodities. Newly submitted information did not provide a basis for
changes in the current limits for cabbage, lettuce, citrus fruit,
potatoes or tomatoes. In the case of tree tomatoes (tamarillos), the
data reflected good agricultural practice in one country and enabled
the meeting to estimate a temporary limit.
Limited domestic and import monitoring data for acephate were
available on commodities for which limits have not been estimated.
RECOMMENDATIONS
The meeting examined residues data from supervised trials
reflecting good agricultural practice on a number of crops. From these
the meeting was able to confirm previously recommended TMRLs and
estimate one new maximum residue level which is recommended as TMRL.
The estimates reflect levels which may occur when acephate is used in
practice and when the reported intervals between last application and
harvest are observed. They refer only to the parent compound.
Pre-harvest interval
Commodity TMRL (mg/kg) on which recommendation
is based
Tree tomato 0.514
(Tamarillo)
REFERENCES
New Zealand Information on good agricultural practice and
1984 supervised residue trials provided by the New Zealand
government.
Bergman, I., Information on residues in food in commerce provided by
1984 the Swedish Contact Point, International Secretariat,
The National Food Administration, May 14, 1984.
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: 1981 evaluations)
Acephate (Pesticide residues in food: 1982 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)