PESTICIDE RESIDUES IN FOOD - 1980
Sponsored jointly by FAO and WHO
EVALUATIONS 1980
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, 6-15 October 1980
CAPTAN
Explanation
Captan has been reviewed by the Joint Meeting on several occasions,
initially in 1965 and most recently in 1978 (FAO/WHO, 1966, 1979).
Maximum limits have been recommended on numerous commodities on the
basis of those reviews.
In response to reservations of two delegations who questioned the need
for a 40 mg/kg limit on cherries, the 8th Session of the Codex
Committee on Pesticide Residues returned the proposal to Step 6 and
requested governments to send data. Data were provided and evaluated
by the 1977 Joint Meeting (FAO/WHO, 1978) which retained the 40 mg/kg
limit pending additional information on national use patterns and
supervised trials. A limited amount of data were provided to the 1978
Joint Meeting (FAO/WHO, 1979) but they were insufficient to enable a
revision the of 1969 recommendation to be made.
The 1980 Meeting was provided with, and evaluated, additional
information on good agricultural practice on apples and potatoes and
residues of captan on cherries after spraying and on potatoes after
post-harvest treatments.
USE PATTERNS
On apples in the Netherlands
A formulation containing 55.37 captan and 16.77 nitrothal-isopropyl
has been used since 1979 to control apple scab and mildew. The
interval between last application and harvest is 21 days.
Treatment Application Rates
g/100l kg/ha
Weekly spray 110 with 1.65 with
from the beginning 34g 0.5kg
of blossoming nitrothal- nitrothal-
until June isopropyl isopropyl
Mid-June until 82.5 with 1.24 with
mid-August, 25.5g 0.38kg
spraying at nitrothal- nitrothal-
10-12 day intervals isopropyl isopropyl
On Potatoes in the USA
In the USA captan is used pre-harvest on potatoes at a rate of 5.6
kg/ha ai, with no limitation between last application and harvest, and
at a rate of 0.12% ai as a spray or dip post-harvest.
RESIDUES IN FOOD
RESIDUES RESULTING FROM SUPERVISED TRIALS
Residue data resulting from pre- and post-harvest uses of captan on
cherries and post-harvest uses on potatoes are summarized in Tables 1
and 2 (Stauffer, 1979; Canada, 1979). The post-harvest treatment data
are the first such data made available.
Although most of the pre-harvest trials on cherries do not reflect the
maximum 0.24% rates permitted by good agricultural practice (FAO/WHO,
1978) they do indicate that residues at 0 day (or even 7-8 days) after
last application can be expected to be at least 20 mg/kg. In fact,
the highest residues resulted from rates of one fourth to one half the
maximum permitted rates. These data therefore are consistent with
earlier pre-harvest data on cherries examined by the Joint Meeting.
The 40 mg/kg limit for captan on cherries previously recommended by
the Joint Meeting was based on pre-harvest uses only. Residues
resulting from post-harvest application approximating good
agricultural practices were 18.4 mg/kg or less in 44 of 45 samples and
44.8 mg/kg for the remaining sample (Stauffer, 1979). The ranges are
given in Table 3.
NATIONAL MAXIMUM RESIDUES LIMITS
The Netherlands reported the following MRLs to the meeting.
Apricots 20 mg/kg
Other fruit and vegetables 15 mg/kg
Wheat 0.1 mg/kg
TABLE 1. Summary of residues of captan on cherries from pre- and post-harvest applications
Country Cultivar/ Year Application Residues1 (mg/kg) at intervals (days) after application
(reference) type no. kg ai/ha formulation 0 1 3-5 7-8 10-12 14-15 17
(spray concen.)
Pre-harvest
Canada Stella 1979 3 1.65 (0.3%) 5OW 0.08-1.5
(1979) (0.67±0.51)
Bing 7 3.4 (0.1%) 0.6-5.7
(3.8±2.2)
Golden 8 3.4 (0.1%) 2.9-5.5
(4.2±1.1)
U.S.A. Bing 1963 1 0.09% 5OW 4.3-6 4.6-5.5 4.5
(Stauffer,
1979) sweet 1975 5 3.4 (0.12%) 0.6
sour 2.6
Bing 1976 2 5.6 (0.24%) 7.9
Montmorency 6 2.2 (0.08%) 13 20 15 5.9 4.3
21.3 11 18.7 20 8.2
Montmorency 6 1.68 (0.06%) 12.3 14.3 8.3 5.5 1.9
20 16.3 9.7 15.5 12.3
Emperor Francis
& Napoleon 1977 7 2.2 (0.06%) 4.3 0.92
Montmorency 7 3.4 (0.12%) 8.2
7.4
TABLE 1. Continued...
Country Cultivar/ Year Application Residues1 (mg/kg) at intervals (days) after application
(reference) type no. kg ai/ha formulation 0 1 3-5 7-8 10-12 14-15 17
(spray concen.)
Montmorency 1978 5 1.1 (0.12%) 80W 16.1 15 9.9 7.4 7.1 2
17.1 5.3 11.2 8.3
Post-harvest
U.S.A. Bing 1963 0.09% 5OW 4.6
(Stauffer, 3.6
1979)
Bing 1 0.14% 80W 1.6-4.7
(2.7±1.2)
Black 4.9
Tatarian 3.9
Chapman 1964 1 0.05% 0.4
0.19% 4.5-11.6
(9.5±2.9)
Bing 2
Lambert 1965 0.12% 50W 0.86 0.94
Chapman 1967 2.9-3.7
(3.3±0.35)
un-named 3.4
3.4
Bing 0.12% flowable 7.2
8.7
TABLE 1. Continued...
Country Cultivar/ Year Application Residues1 (mg/kg) at intervals (days) after application
(reference) type no. kg ai/ha formulation 0 1 3-5 7-8 10-12 14-15 17
(spray concen.)
U.S.A. un-named 1967 1 0.12% 50W <0.05-4
(0.9±1.1)
1968 1 80W 18.4
16
0.12% flowable 14.8
13.5
1 Mean and standard deviation in brackets.
TABLE 2. Summary of Residues of Captan on Potatoes from Post-harvest treatments in USA
State Year Applications Residue (mg/kg)
no. % concentration formulation after dipping
ai in dip
Washington 1954 1 0.12 50W 9.0
13.2 (3.4 after washing)
3.7 (0.8; 0.8 after scrubbing)
1954 1 0.12 50W 8.6
12.3
6.9
7.8
1955 1 0.24 50W 4.3
3.7
1955 1 0.12 50W 3.0
4.0
1 0.24 50W 9.3
7.8
1 0.12 50W 5.5
5.2
California 1955 1 0.12 50W 7.1
8.0
4.4
5.0
5.6
6.0
0.24 50W 6.3
7.0
9.5
9.8
TABLE 2. Continued...
State Year Applications Residue (mg/kg)
no. % concentration formulation after dipping
ai in dip
North 1955 1 0.12 50W 3.5
Carolina 4.3
4.9
4.8
3.2
4.0
3.3
3.3
Idaho 1955 1 0.12 50W 3.4
3.4
3.3
3.7
0.24 50W 5.7
6.5
10.5
10.0
New York 1955 1 0.12 50W 2.5
2.0
2.6
1.9
2.5
2.1
2.2
2.2
3.0
3.2
4.2
4.0
TABLE 2. Continued...
State Year Applications Residue (mg/kg)
no. % concentration formulation after dipping
ai in dip
Oregon 1955 0.12 50W 3.5
3.4
4.2
4.8
0.24 50W 4.0
4.1
7.0
6.9
Stauffer, 1980
TABLE 3. Captan residues on cherries from post-harvest uses (at day
of application)
Range Number Percent
(mg/kg) in range in range
40-45 1 2.2
20-39.9 0 0.0
15-19.9 2 4.4
10-14.9 5 11.1
5-9.9 3 6.7
0.05-4.9 34 75.6
Total 45 100.0
EVALUATION
APPRAISAL
The meeting was provided with additional information on good
agricultural practice and further residue data for captan on cherries
and potatoes.
In the case of cherries, the Joint Meeting had previously recommended
a 40 mg/kg limit for captan on the basis of residue data resulting
from pre-harvest applications. Subsequent review of additional
residue data resulting from pre-harvest uses did not support a
proposed reduction of that limit. The additional pre-harvest data,
and for the first time, residue data from post-harvest applications
are reviewed in this addendum and considered in conjunction with data
previously evaluated.
The newly submitted pre-harvest data, resulting mostly from
application rates of less than the maximum permitted by good
agricultural practice, are consistent with the earlier findings. At
the maximum application rates permitted by good agricultural practice,
previous evaluations had shown that residues may be up to 53 mg/kg at
0 day or 25-29 mg/kg at 7-9 days after last application. On the basis
of pre-harvest data alone therefore, there is no justification for a
limit lower than the 40 mg/kg limit previously recommended. The
recently submitted post-harvest data show that residues on cherries,
like those from pre-harvest uses, can exceed 40 mg/kg.
In the case of potatoes, residues can approach 15 mg/kg from
post-harvest uses alone. Good agricultural practises in some
countries allow higher rates and shorter intervals for pre-harvest
treatments than previously considered although no data were available
for those uses.
On the basis of the new data the Meeting found it necessary and was
able to estimate new maximum residue levels for cherries and potatoes
to cover pre- and post-harvest uses on cherries and post-harvest uses
on potatoes.
RECOMMENDATIONS OF RESIDUES LIMITS
The meeting concluded that the levels listed below were suitable for
establishing maximum residue limits to replace the existing figures.
Commodity Estimated Maximum Residue Levels (mg/kg)
Cherries 50
Potatoes 20
FURTHER WORK OR INFORMATION
Desirable
Additional information on national use patterns and corresponding
residue data from supervised trials, in particular from pre-harvest
uses on potatoes.
REFERENCES
Canada. (1979) Studies conducted by Agriculture Canada Central
Experimental Farm, Ottawa Canada, KIA 0C5 and made available by Peter
R. Bennett, Division of Additives and Pesticides, Food Directorate,
Health Protection Branch, Health and Welfare Canada, Ottawa, Canada,
K1A 0L2.
Stauffer. (1979) Unpublished reports submitted by Stauffer Chemical
Company, 1200 South 47th Street, Richard, California 94804.
Pre-harvest studies are identified as FSDS No. A-14005, A-17638,
A-17635, A-13626, A-13627, A-17616, A-13621, A-13622, A-19931,
A-17615, and A-12730 and Ag. Tox. Report 409. Post-harvest studies are
in Ag. Tor. Reports 409, 411, 419, 421, 502, 503, 760, 993, 1002,
1035, 1233, and 1234 Agricultural Toxicology, University of
California, Davis.
Stauffer. (1980) Unpublished reports submitted from the California
Spray-Chemical Corporation, dated October 5 and October 14, 1955 from
James M. Cripps and entitled 'Captan-potatoes'.
See Also:
Toxicological Abbreviations
Captan (HSG 50, 1990)
Captan (ICSC)
Captan (PIM 098)
Captan (FAO/PL:1969/M/17/1)
Captan (WHO Pesticide Residues Series 3)
Captan (WHO Pesticide Residues Series 4)
Captan (Pesticide residues in food: 1977 evaluations)
Captan (Pesticide residues in food: 1978 evaluations)
Captan (Pesticide residues in food: 1982 evaluations)
Captan (Pesticide residues in food: 1984 evaluations)
Captan (Pesticide residues in food: 1984 evaluations)
Captan (Pesticide residues in food: 1990 evaluations Toxicology)
Captan (Pesticide residues in food: 1995 evaluations Part II Toxicological & Environmental)
Captan (IARC Summary & Evaluation, Volume 30, 1983)