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
CHLOROTHALONIL
Explanation
Chlorothalonil was evaluated in 1974, 1977, 1978 and 1979.* After
receiving data on toxicological studies, performed under a variety of
experimental conditions on several animal species, a temporary ADI of
0.03 mg/kg bw was established.
In order to answer the still open questions pertaining to the
safety evaluation of chlorothalonil, the 1979 Meeting required
that studies be conducted to define the growth reduction after
administration of the parent compound or its major metabolite,
4-hydroxy-2,5,6-trichloroisophthalonitrile, in pups relative to
ingestion or secretion into milk.
Furthermore, it was considered desirable that additional
information be provided comprising: 1) the elucidation of
discrepancies in the carcinogenicity studies; 2) observations on
occupationally exposed humans, and 3) the extent of metabolism of
chlorothalonil in mammals.
New material dealing with some of the subject areas enumerated
was submitted. No data on the metabolism of chlorothalonil were
received. The Meeting was, however, informed that investigations are
currently under way to study the metabolic profile (e.g, biliary,
faecal and urinary metabolites, tissue residues) in mice, rats and
dogs. The results of these studies are expected to be submitted for
consideration at a later date.
Temporary maximum residue limit recommendations on a variety of
commodities were made on the basis of previous evaluations. The 1979
Meeting concluded that further information in several areas was either
required by 1981 or considered desirable. Of those studies considered
desirable were (1) experimental information on the possible occurrence
of hexachlorobenzene residues on crops requiring multiple treatments,
and (2) results of ongoing studies on the effects of cooking under
closed conditions on residue levels and chemical composition. This
monograph addendum reviews data submitted on these two items, as well
as some additional information on residues and national use patterns
and tolerances.
* See Annex II for FAO and WHO documentation.
DATA FOR THE ESTIMATION OF ACCEPTABLE DAILY INTAKE
TOXICOLOGICAL STUDIES
Special studies to define growth reduction after administration of
4-hydroxy-2,5,6,trichloroisophthalonitrile (DS-3701)
Rat
A metabolite of chlorothalonil, DS-3701, was investigated in a
3-generation/reproduction study in Sprague-Dawley derived (CD) rats.
The test compound was given continuously in the diet beginning at age
43 days of the F0 generation, at levels of 10, 60 and 125 ppm. An
additional group received the same diet (Purina Laboratory Chow),
however, without the test compound.
Each of the 3 generations, consisting of 4 groups of 15 male and
30 female rats, was mated twice, the first time at the age of at least
142 days (F0) or 121 days (F1 and F2), and the second time after a
rest period of at least 14 days following the weaning of the first
litter.
Body weight, physical condition, food consumption, data on the
reproductive cycles (e.g. pregnancy rate, fertility indices, viability
and survival of offspring, mating, littering and mortality) were
monitored.
The experiments were terminated by killing the survivors with
ether (parents after weaning the second litter; offspring not selected
as parents for the next generation at age 21 days). A post-mortem
examination was performed.
Apart from the significant reduction in body weight at the 60 and
125 ppm levels, no substance-related changes could be observed. It
should, however, be noted that during the entire study selected organs
of only 5 animals were histopathologically examined. Interpretation of
ocular lesions (e.g. keratitis, corneal ulcers, iritis and pitted
corneas), frequently encountered, particularly in treated animals of
the F1 generation, is difficult. These lesions may, however, be due
to the apparent infection of the test animals, both control and
treated, with sialodacryoadenitis (SDA) virus.
In these studies, a no-effect level of 10 ppm could be
established.
OBSERVATIONS ON OCCUPATIONALLY EXPOSED HUMANS
Dermatological observations
Among the 191 participants in an annual medical screening of
employees of a chlorothalonil manufacturing plant, 2 persons were
found with dermatological symptoms. The relevance of the changes to
occupational exposure was questionable (Diamond Shamrock 1980).
In a manufacturing plant, of the 103 employees working directly
with chlorothalonil 60.2% showed some type of skin abnormality,
including 19 cases of so-called Daconil (chlorothalonil) contact
dermatitis.
Of the 45 employees not working with chlorothalonil, 18.5% showed
skin disorders including 2 cases of Daconil contact dermatitis. As a
consequence of improved industrial hygiene, a year later the rate of
skin abnormalities considerably decreased (to 21.1% and 16%
respectively). No Daconil contact dermatitis was found (Diamond
Shamrock 1980).
Inhalation and dermal exposure of applicators to chlorothalonil and
hexachlorobenzene(HCB)
Eleven workers, normally engaged in mixing, loading or
application of pesticides in the field, participated in a study
monitoring the level of inhalation and dermal exposure to and urinary
excretion of chlorothalonil. As commercial preparations contain some
HCB (in the present study < 0.02%), the measurement of this
contaminant was also included.
Under the conditions specified in the label directions, the
effect of aerial and ground application, at both maximum and common
rate of use, was studied.
The highest single dermal exposure was measured on hands
(1.7 mg/m2/h); the dermal LD50 for rabbits is 10 g/kg bw. The
highest single inhalation exposure, expressed as a percentage of the
LC50 for rats, was 1%. The majority of the individual data were less
than one-tenth of that.
It was therefore concluded that, on the basis of exposure levels
measured, dermal and inhalation exposure to chlorothalonil constitutes
a very low hazard to agricultural applicators. The level of exposure
to HCB was below the sensitivity of the analytical method used
(Diamond Shamrock 1980).
RESIDUES IN FOOD
USE PATTERN
United States
Current registered USA uses for formulations (or similar ones)
utilized on commodities for which field trials were conducted in this
monograph are given in Table 1.
TABLE 1. Uses registered in USA for chlorothalonil
Application rate
Formulation Commodity kg a.i./ha at intervals Pre-harvest
(days) Interval (days)
BRAVONIL 500 celery 0.84-1.23 (3-5) 7
and BRAVO W-75 1.7 -2.52 (7) 7
cucumber 1.7 -2.52 (7) none
potato 0.84-1.23 (7-10) none
snap beans 2.6 7
tomato 1.23-2.52 (7-14) none
BRAVO 500 soybean 0.87-2.07 (2 applications) 6 weeks
1.6 (3 applications)
(14)
Netherlands
Present uses of chlorothalonil in The Netherlands are summarized
in Table 2.
RESIDUES RESULTING FROM SUPERVISED TRIALS
Field trials were conducted in Europe and the United States on a
variety of selected commodities to develop data to answer questions
concerning possible residues of hexachlorobenzene (HCB) resulting from
multiple applications of chlorothalonil under a variety of conditions
and using various modes of application.
TABLE 2. Uses for chlorothalonil in the Netherlands
Crop or Kind of pest Extent of use/ Application rate Treatment Pre-harvest In use
Situation controlled economic kg a.i./ha Formulation first interval since
importance (g/100 l) w.p.25% + treatment (days)
Potato Phytophthora small scale 1.5-2.2 75% w.p. repeated 1966
Potato Phytophthora moderate 0.75-1.0 w.p.25% + treatments 1976
50% maneb "
Mushroom Verticillium sp. small scale 2.25 g/m2 75% w.p. first treatment 5 1977
after covering.
repeat two weeks
later after first
harvest
Mushroom green mildew 1.15 g/m2 75% w.p. Spray immediately 5 1978
(115) after 1st and 2nd
harvest.
Gherkin Mycosphaerella (150) 75% w.p. Spray repeatedly 3 1979
and (cucumber)
Cucumber downy mildew 1977
Melon
Leek Phytophthora (150) 75% w.p. spray every 10-14 14 1979
porri and days
Celeriac Puccinia allii
Septoria apiicola 1.9 75% w.p. spray every 10-14 28 1979
Blanched days
celery
Onion Botrytis squamosa 1.5 75% w.p. spray from beginning 28 1979
Shallot (1.5) of June, repeat
every 7-10 days
TABLE 2. (con't)
Crop or Kind of pest Extent of use/ Application rate Treatment Pre-harvest In use
Situation controlled economic kg a.i./ha Formulation first interval since
importance (g/100 l) w.p.25% + treatment (days)
Onion Botrytis squamosa small scale 0.5 w.p. 25% " 28 1979
Shallot (0.5) + 50% maneb (Onion 1976)
powdery mildew moderate 1.2 w.p. 20% + 1 treatment,
Wheat ripening (1.2) 40% sulphur repeat once, if 42
diseases + 20% maneb necessary, just
before blossoming
Tomato Botrytis (150) spray repeatedly 3
Septoria apiicola
Phytophthora
Courgettes Mycosphaerella (150)
(zucchini) downy mildew 3
Strawberry 14
(under (alternate)
consideration)
Other uses: in floriculture and against blue staining of wood.
The commodities chosen were selected to represent commodities for
which there are Codex temporary maximum residue limits (MRLs) or
established national tolerances. The formulations used were Bravo 500
(a water dispersible flowable formulation containing 500 g of
chlorothalonil per 1) and Bravo W-75, (a wettable powder formulation
containing 75% chlorothalonil). Two batches of Bravo 500 and Bravo
W-75 were used and contained maximum levels of 0.02% HCB and 0.62%
PCBN and 0.04% HCB and 0.82% PCBN, respectively, as impurities.
As carrot and celery samples from Florida have reportedly
contained residues of pentachlorobenzonitrile (PCBN), and as it has
been implied that these reported residues may have been associated
with applications of chlorothalonil (Barry et al 1977), samples were
also analysed for PCBN. Residues of chlorothalonil were also
determined, but 4-hydroxy-2,5,6-trichloro-1,3-benzenedicarbonitrile
(which is included in the Codex temporary MRLs) was not.
Residues for chlorothalonil, HCB and PCBN resulting from up to 15
applications during field trials on eight commodities, representing
approximately 40 studies and over 600 samples analysed, are summarized
in Table 3 (United States studies) and Table 4 (European studies).
In addition to the studies provided to answer questions on
possible residue of HCB, information is also provided from residue
trials in The Netherlands in Table 5.
Celery
After up to 15 broadcast treatments with Bravo 500 or Bravo W-75
at the maximum recommended active label rate of 2.5 kg/ha by boom
sprayer, maximum residues on unwashed celery were 13.7 mg/kg
chlorothalonil, and 0.157 mg/kg PCBN on day of last application.
Maximum residues of HCB were 0.009 mg/kg. After seven days (interval
used as a basis for Codex temporary MRLs), maximum residues on
unwashed celery were 3.8 mg/kg chlorothalonil, 0.003 mg/kg HCB and
0.062 mg/kg PCBN. Residues at day of application were even less when
washed according to commercial practices. However, inconsistent or no
reduction could be observed for chlorothalonil after a seven-day
interval and residues were too low to make an assessment for HCB
residues.
Maximum apparent residues after seven days on untreated, unwashed
samples were 0.05, < 0.003 and 0.008 mg/kg for chlorothalonil, HCB
and PCBN, respectively.
When treated with the above two formulations according to the
given rates and conditions, and analysed after a seven-day interval
from last application, residues of chlorothalonil alone were well
below the temporary MRL of 15 mg/kg. Maximum residues of HCB are
TABLE 3.
Summary of results from United States field residue studies to determine the
presence and amounts of chlorothalonil (2,4,5,6-tetrachloroisophthalonitrile), HCB (hexachlorobenzene)
and PCBN (pentachlorobenzonitrile) in various crops treated with chlorothalonil products.
RATE
FORMULA- NUMBER OF TREATMENT RESIDUES (PPM)1
TION AND APPLICA- TO
CROP PRODUCT APPLICA- [SPRAY ACTIVE TIONS, HARVEST CHLOROTHALONIL HCB PCBN NUMBER
AND LOCATION FORMU- TION VOLUME INGREDIENT TABLE IN INTERVAL HIGH HIGH HIGH SAMPLES
REFERENCE* AND YEAR LATION METHOD (L/HA)]** (KG/HA) REPORT (DAYS) MEAN VALUE MEAN VALUE MEAN VALUE ANALYZED
Celery3 Florida Bravo Boom 3.36 2.5 15 0 11.75 13.72 0.004 0.009 0.138 0.157 6
(1) 1979 W-75 Sprayer kg/ha Table 4 7 1.44 1.64 ND 0.003 0.054 0.062 6
(broad- [374 samples 14 2.94 3.76 ND ND 0.044 0.057 6
cast) l/ha] unwashed
15 0 0.96 1.23 ND ND 0.034 0.049 6
Table 5 7 2.19 2.99 ND ND 0.027 0.035 6
samples 14 1.33 1.61 ND ND 0.021 0.027 6
washed
Bravo Boom 4.97 l/ha 2.5 15 0 3.15 4.16 ND 0.003 0.057 0.079 6
500 Sprayerl [374 Table 6 7 0.29 0.37 ND ND 0.027 0.036 6
(broad- l/ha] samples 14 0.92 1.44 ND ND 0.025 0.030 6
cast) unwashed
15 0 0.66 0.99 ND ND 0.020 0.030 6
Table 7 7 0.62 0.80 ND ND 0.014 0.022 6
samples 14 0.43 0.51 ND ND 0.010 0.014 6
washed
TABLE 3 (con't)
RATE
FORMULA- NUMBER OF TREATMENT RESIDUES (PPM)1
TION AND APPLICA- TO
CROP PRODUCT APPLICA- [SPRAY ACTIVE TIONS, HARVEST CHLOROTHALONIL HCB PCBN NUMBER
AND LOCATION FORMU- TION VOLUME INGREDIENT TABLE IN INTERVAL HIGH HIGH HIGH SAMPLES
REFERENCE* AND YEAR LATION METHOD (L/HA)]** (KG/HA) REPORT (DAYS) MEAN VALUE MEAN VALUE MEAN VALUE ANALYZED
Celery UN- -- -- -- Table 8 0 0.33 0.42 ND ND 0.009 0.013 6
(1) TREATED samples 7 0.02 0.05 ND ND 0.005 0.008 6
(con't) unwashed 14 0.04 0.06 ND ND ND 0.005 6
Table 9 0 0.03 0.07 ND ND ND 0.012 6
samples 7 0.03 0.04 ND ND ND ND 6
washed 14 0.04 0.05 ND ND ND ND 6
Cucumber Florida Bravo Boom 4.97 l/ha 2.5 7 0 0.18 0.33 ND ND ND 0.006 6
(2) 1979 500 Sprayer [374 Table 4 7 0.02 0.02 ND ND ND ND 6
l/ha] 14 ND ND ND ND ND ND 6
7 0 0.10 0.18 ND ND ND 0.005 6
Table 5 7 0.01 0.01 ND ND ND ND 6
14 ND 0.01 ND ND ND ND 6
Bravo Boom 3.36 2.5 7 0 0.86 1.09 ND ND ND 0.006 6
W-75 Sprayer kg/ha Table 6 7 0.02 0.03 ND ND ND ND 6
[374 14 0.01 0.01 ND ND ND ND 6
l/ha]
UN- -- -- -- 0 0 0.01 0.03 ND ND ND ND 3
TREATED Table 7 7 ND 0.01 ND ND ND ND 3
14 ND ND ND ND ND ND 3
TABLE 3 (con't)
RATE
FORMULA- NUMBER OF TREATMENT RESIDUES (PPM)1
TION AND APPLICA- TO
CROP PRODUCT APPLICA- [SPRAY ACTIVE TIONS, HARVEST CHLOROTHALONIL HCB PCBN NUMBER
AND LOCATION FORMU- TION VOLUME INGREDIENT TABLE IN INTERVAL HIGH HIGH HIGH SAMPLES
REFERENCE* AND YEAR LATION METHOD (L/HA)]** (KG/HA) REPORT (DAYS) MEAN VALUE MEAN VALUE MEAN VALUE ANALYZED
Cucumber Bravo Boom 4.97 l/ha 2.5 7 0 0.86 1.20 ND ND 0.021 0.028 6
(2) 500 Sprayer [374 Table 8 7 0.46 0.63 ND 0.004 0.006 0.010 6
(con't) l/ha] 14 0.12 0.18 ND ND ND 0.005 6
7 0 0.84 1.43 ND ND 0.018 0.027 6
Table 9 7 0.32 0.53 ND 0.005 0.007 0.014 6
14 0.06 0.11 ND ND ND 0.007 6
Bravo Boom 3.36 2.5 7 0 0.57 0.75 ND 0.003 0.011 0.016 6
W-75 Sprayer kg/ha Table 10 7 0.37 0.57 ND 0.003 ND 0.008 6
[374 14 0.12 0.18 ND ND ND 0.007 6
l/ha]
UN- -- -- -- Table 11 0 0.02 0.03 ND ND ND ND 3
TREATED 7 0.02 0.04 ND 0.003 ND ND 3
14 ND 0.01 ND ND ND ND 3
Ohio Bravo Pressu- 4.97 l/ha 2.5 8 0 0.25 0.50 ND ND 0.012 0.013 6
1979 500 rized [1402 Table 12 7 0.12 0.14 ND ND ND 0.007 6
Hand l/ha] 14 0.12 0.19 ND ND ND 0.006 6
Sprayer 8 0 0.33 0.60 ND ND 0.008 0.013 6
Table 13 7 0.19 0.34 ND ND ND ND 6
14 0.10 0.11 ND ND ND 0.006 6
TABLE 3 (con't)
RATE
FORMULA- NUMBER OF TREATMENT RESIDUES (PPM)1
TION AND APPLICA- TO
CROP PRODUCT APPLICA- [SPRAY ACTIVE TIONS, HARVEST CHLOROTHALONIL HCB PCBN NUMBER
AND LOCATION FORMU- TION VOLUME INGREDIENT TABLE IN INTERVAL HIGH HIGH HIGH SAMPLES
REFERENCE* AND YEAR LATION METHOD (L/HA)]** (KG/HA) REPORT (DAYS) MEAN VALUE MEAN VALUE MEAN VALUE ANALYZED
Cucumber Bravo Pressu- 3.36 2.5 8 0 0.23 0.44 ND ND ND 0.012 6
(2) W-75 rized kg/ha Table 14 7 0.14 0.27 ND ND ND 0.008 6
(con't) Hand [1423 14 0.07 0.08 ND ND ND 0.005 6
Sprayer l/ha
UN- -- -- -- Table 15 0 0.04 0.06 ND ND ND ND 3
TREATED 7 0.01 0.02 ND ND ND ND 3
14 ND ND ND ND ND ND 3
(3) Michigan Bravo Sprink- 2.63 1.32 6 0 0.06 0.09 ND ND ND ND 6
1979 500 ler l/ha2 Table 4 7 0.05 0.07 ND 0.005 ND ND 6
Irriga- [NA]
tion
UN- -- -- -- Table 5 -- 0.01 0.02 ND ND ND ND 4
TREATED
Oranges Florida Bravo Mist 5.85 l/ha 2.93 1 208 ND ND ND ND 0.010 0.014 4
(4) 1979 500 Blower [2339 Table 5
l/ha]
5.85 l/ha 2.93 1 208 ND ND iND ND 0.013 0.013 4
[4677
l/ha]
TABLE 3 (con't)
RATE
FORMULA- NUMBER OF TREATMENT RESIDUES (PPM)1
TION AND APPLICA- TO
CROP PRODUCT APPLICA- [SPRAY ACTIVE TIONS, HARVEST CHLOROTHALONIL HCB PCBN NUMBER
AND LOCATION FORMU- TION VOLUME INGREDIENT TABLE IN INTERVAL HIGH HIGH HIGH SAMPLES
REFERENCE* AND YEAR LATION METHOD (L/HA)]** (KG/HA) REPORT (DAYS) MEAN VALUE MEAN VALUE MEAN VALUE ANALYZED
Oranges 8.19 l/ha 4.10 1 208 ND ND ND ND 0.013 0.017 4
(4) [2337
(con't) l/ha]
8.19 l/ha 4.10 1 208 ND ND ND ND 0.015 0.02 4
[4677
l/ha]
UN- -- -- -- -- -- ND ND ND ND 0.013 0.014 3
TREATED
Bravo Mist 5.85 l/ha 2.93 1 221 ND ND 0.001 0.003 0.011 0.013 4
500 Blower [2339 Table 6
l/ha]
5.85 l/ha 2.93 1 221 ND NO ND ND 0.014 0.015 4
[4676
l/ha]
8.19 l/ha 4.10 1 221 ND ND ND ND 0.014 0.015 4
[2339
l/ha]
8.19 l/ha 4.10 1 221 ND ND ND ND 0.014 0.015 4
[4676
l/ha]
UN- -- -- -- -- -- ND ND ND ND 0.013 0.014 3
TREATED
TABLE 3 (con't)
RATE
FORMULA- NUMBER OF TREATMENT RESIDUES (PPM)1
TION AND APPLICA- TO
CROP PRODUCT APPLICA- [SPRAY ACTIVE TIONS, HARVEST CHLOROTHALONIL HCB PCBN NUMBER
AND LOCATION FORMU- TION VOLUME INGREDIENT TABLE IN INTERVAL HIGH HIGH HIGH SAMPLES
REFERENCE* AND YEAR LATION METHOD (L/HA)]** (KG/HA) REPORT (DAYS) MEAN VALUE MEAN VALUE MEAN VALUE ANALYZED
Oranges Bravo Mist 5.85 l/ha 2.93 1 217 ND ND ND ND 0.016 0.021 4
(4) 500 Blower [2339 Table 7
(con't) l/ha]
5.85 l/ha 2.93 1 217 ND ND ND ND 0.018 0.022 4
[4676
l/ha]
8.19 l/ha 4.10 1 217 ND ND ND ND 0.017 0.020 4
[2339
l/ha]
8.19 l/ha 4.10 1 217 ND ND ND ND 0.017 0.021 4
[4676
l/ha]
UN- -- -- -- -- -- ND ND ND ND 0.017 0.019 3
TREATED
Potatoes Florida Bravo Boom 2.49 l/ha 1.25 9 0 0.09 0.11 ND 0.004 ND ND 6
(5) 1979 500 Sprayer [468 Table 4
l/ha]
9 0 0.08 0.11 ND ND ND 0.008 6
Table 5
Bravo Boom 1.68 1.25 9 0 0.12 0.18 ND 0.003 ND ND 6
W-75 Sprayer kg/ha Table 6
[468
l/ha]
TABLE 3 (con't)
RATE
FORMULA- NUMBER OF TREATMENT RESIDUES (PPM)1
TION AND APPLICA- TO
CROP PRODUCT APPLICA- [SPRAY ACTIVE TIONS, HARVEST CHLOROTHALONIL HCB PCBN NUMBER
AND LOCATION FORMU- TION VOLUME INGREDIENT TABLE IN INTERVAL HIGH HIGH HIGH SAMPLES
REFERENCE* AND YEAR LATION METHOD (L/HA)]** (KG/HA) REPORT (DAYS) MEAN VALUE MEAN VALUE MEAN VALUE ANALYZED
Potatoes UN- -- -- -- Table 13 -- 0.01 0.2 ND ND ND ND 2
(5) TREATED
(con't)
Bravo Boom 2.49 l/ha 1.25 11 0 0.05 0.07 ND 0.004 ND 0.008 6
500 Sprayer [374 Table 7
l/ha]
11 0 0.04 0.06 ND 0.003 ND 0.006 6
Table 8
Bravo 1.68 1.25 11 0 0.06 0.13 ND ND ND 0.008 6
W-75 kg/ha Table 9
[374
l/ha]
UN- -- -- -- Table 13 -- 0.01 0.02 ND ND ND ND 6
TREATED
Idaho Bravo NA2 2.49 l/ha 1.25 2 0 0.02 0.02 ND ND ND ND 6
1979 500 NA2 Table 10
UN- -- -- -- Table 13 -- 0.01 0.02 ND ND ND ND 6
TREATED
TABLE 3 (con't)
RATE
FORMULA- NUMBER OF TREATMENT RESIDUES (PPM)1
TION AND APPLICA- TO
CROP PRODUCT APPLICA- [SPRAY ACTIVE TIONS, HARVEST CHLOROTHALONIL HCB PCBN NUMBER
AND LOCATION FORMU- TION VOLUME INGREDIENT TABLE IN INTERVAL HIGH HIGH HIGH SAMPLES
REFERENCE* AND YEAR LATION METHOD (L/HA)]** (KG/HA) REPORT (DAYS) MEAN VALUE MEAN VALUE MEAN VALUE ANALYZED
Potatoes New York Bravo 8-row 2.49 l/ha 1.25 9 0 0.01 0.01 ND ND ND ND 6
(5) 1979 500 Boom [824 Table 11
(con't) Sprayer l/ha]
Bravo 8-row 1.68 1.25 9 0 0.01 0.02 ND ND ND ND 6
W-75 Boom kg/ha Table 12
Sprayer
UN- -- -- -- Table 13 -- 0.01 0.02 ND ND ND ND 6
TREATED
Snapbeans Ohio Bravo Pressu- 4.97 l/A 2.50 2 0 2.56 3.55 ND 0.003 0.056 0.077 6
(6) 1979 500 rized Table 5 7 1.16 1.29 ND ND 0.024 0.025 6
Hand [935 14 0.24 0.46 ND ND 0.006 0.027 6
Sprayer l/ha] 2 0 1.81 3.65 ND 0.003 0.044 0.073 6
Table 6 7 1.10 1.32 ND ND 0.021 0.024 6
14 0.67 0.98 ND ND 0.018 0.028 6
Bravo Pressu- 3.36 2.50 2 0 2.44 2.87 ND ND 0.038 0.041 6
W-75 rized kg/ha Table 7 7 1.67 1.99 ND ND 0.034 0.042 6
Hand [935 14 0.49 0.59 ND ND ND 0.016 6
Sprayer l/ha]
UN- -- -- -- Table 4 0 0.12 0.13 ND ND ND ND 3
TREATED 7 0.01 0.02 ND 0.003 ND ND 3
14 0.01 0.01 ND ND ND ND 3
TABLE 3 (con't)
RATE
FORMULA- NUMBER OF TREATMENT RESIDUES (PPM)1
TION AND APPLICA- TO
CROP PRODUCT APPLICA- [SPRAY ACTIVE TIONS, HARVEST CHLOROTHALONIL HCB PCBN NUMBER
AND LOCATION FORMU- TION VOLUME INGREDIENT TABLE IN INTERVAL HIGH HIGH HIGH SAMPLES
REFERENCE* AND YEAR LATION METHOD (L/HA)]** (KG/HA) REPORT (DAYS) MEAN VALUE MEAN VALUE MEAN VALUE ANALYZED
Snapbeans Florida Bravo Pressu- 3.36 2.50 7 0 0.89 1.35 ND ND 0.024 0.038 6
(6) 1979 W-75 rized kg/ha Table 11 7 0.49 0.61 ND ND 0.012 0.016 6
(con't) Hand [468 14 0.17 0.21 ND ND ND ND 6
Sprayer l/ha]
over row
Bravo Pressu- 4.97 l/A 2.50 7 0 0.85 1.03 ND ND 0.030 0.039 6
500 rized [468 Table 9 7 0.33 0.39 ND ND ND 0.012 6
Hand l/ha] 14 0.09 0.10 ND ND ND ND 6
Sprayer 7 0 0.68 0.89 ND ND 0.020 0.030 6
Over Table 10 7 0.40 0.60 ND ND 0.015 0.017 6
Row 14 0.07 0.11 ND ND ND ND 6
UN- -- -- -- Table 8 0 0.01 0.01 ND ND ND 0.005 3
TREATED 7 0.02 0.04 ND ND ND ND 3
14 ND ND ND ND ND ND 3
Bravo Boom 4.97 l/ha 2.50 7 0 0.11 0.11 ND ND 0.018 0.024 2
500 Sprayer [374 Table 13 7 0.14 0.16 ND ND 0.007 0.013 2
l/ha] 14 0.04 0.05 ND ND ND 0.008 2
7 0 1.77 1.80 ND ND 0.010 0.02 2
Table 14 7 0.13 0.15 ND ND ND ND 2
14 0.05 0.05 0.007 0.014 ND ND 2
TABLE 3 (con't)
RATE
FORMULA- NUMBER OF TREATMENT RESIDUES (PPM)1
TION AND APPLICA- TO
CROP PRODUCT APPLICA- [SPRAY ACTIVE TIONS, HARVEST CHLOROTHALONIL HCB PCBN NUMBER
AND LOCATION FORMU- TION VOLUME INGREDIENT TABLE IN INTERVAL HIGH HIGH HIGH SAMPLES
REFERENCE* AND YEAR LATION METHOD (L/HA)]** (KG/HA) REPORT (DAYS) MEAN VALUE MEAN VALUE MEAN VALUE ANALYZED
Snapbeans Bravo Boom 3.36 2.50 7 0 0.08 0.11 ND ND 0.015 0.021 2
(6) W-75 Sprayer kg/ha Table 15 7 0.53 0.57 ND ND ND ND 2
(con't) [374 14 0.22 0.24 ND ND 0.006 0.011 2
l/ha]
UN- -- -- -- Table 12 0 0.02 0.02 ND ND ND ND 2
TREATED 7 ND ND ND ND ND ND 2
14 0.01 0.01 ND ND ND ND 2
New York Bravo Commer- 4.97 l/ha 2.5 4 0 2.40 3.50 ND ND 0.038 0.048 6
1979 500 cial [412 Table 17 7 2.07 3.04 ND ND 0.036 0.042 6
Boom l/ha] 14 1.26 1.88 ND ND 0.034 0.038 6
Sprayer
UN- -- -- -- Table 16 0 0.01 0.01 ND ND ND ND 3
TREATED 7 ND ND ND ND ND ND 3
14 ND ND ND ND ND ND 3
Soybeans Kentucky Bravo Pressu- 2.34 l/ha 1.17 2 57 ND 0.013 ND ND 0.009 0.010 6
(7) (1979) 500 rized [430 Table 5
Sprayer l/ha]
UN- -- -- -- -- -- ND ND ND ND 0.010 0.017 6
TREATED
TABLE 3 (con't)
RATE
FORMULA- NUMBER OF TREATMENT RESIDUES (PPM)1
TION AND APPLICA- TO
CROP PRODUCT APPLICA- [SPRAY ACTIVE TIONS, HARVEST CHLOROTHALONIL HCB PCBN NUMBER
AND LOCATION FORMU- TION VOLUME INGREDIENT TABLE IN INTERVAL HIGH HIGH HIGH SAMPLES
REFERENCE* AND YEAR LATION METHOD (L/HA)]** (KG/HA) REPORT (DAYS) MEAN VALUE MEAN VALUE MEAN VALUE ANALYZED
Soybeans Missouri Bravo aerial 12.34 1.17 2 45 0.013 0.017 0.005 0.006 0.005 0.008 6
(7) 1979 500 l/ha NA2 Table 6
(con't)
UN- -- -- -- -- -- 0.019 0.039 0.004 0.006 0.009 0.013 6
TREATED
NA2 2.34 l/ha 1.17 2 47 ND 0.010 ND ND ND 0.007 6
[187 Table 7
l/ha]
UN- -- -- -- -- -- ND 0.010 ND 0.003 ND 0.008 6
TREATED
Ohio Bravo Pressu- 4.09 l/ha 2.05 2 54 0.013 0.019 ND ND 0.015 0.016 6
1979 500 rized [468 Table 8 54 0.015 0.018 ND ND 0.013 0.014 6
Hand l/ha]
Sprayer
UN- -- -- -- -- -- ND ND ND ND 0.016 0.023 6
TREATED
Florida Bravo Boom 3.36 2.50 2 43 ND ND ND ND 0.016 0.021 6
1979 W-75 Sprayer kg/ha Table 9
[374
l/ha]
TABLE 3 (con't)
RATE
FORMULA- NUMBER OF TREATMENT RESIDUES (PPM)1
TION AND APPLICA- TO
CROP PRODUCT APPLICA- [SPRAY ACTIVE TIONS, HARVEST CHLOROTHALONIL HCB PCBN NUMBER
AND LOCATION FORMU- TION VOLUME INGREDIENT TABLE IN INTERVAL HIGH HIGH HIGH SAMPLES
REFERENCE* AND YEAR LATION METHOD (L/HA)]** (KG/HA) REPORT (DAYS) MEAN VALUE MEAN VALUE MEAN VALUE ANALYZED
Soybeans Bravo Boom 4.97 l/ha 2.50 2 43 ND ND ND ND 0.020 0.024 6
(7) 500 Sprayer [374 ND ND ND ND 0.018 0.020 6
(con't) l/ha]
UN- -- -- -- -- -- ND ND ND ND 0.19 0.024 6
TREATED
Texas Bravo Backpack 4.09 l/ha 2.05 2 40 ND ND ND ND 0.008 0.008 8
1979 500 Mist [187 Table 10
blower l/ha]
UN- -- -- -- -- -- ND 0.014 ND ND 0.008 0.008 6
TREATED
Tomatoes Ohio Bravo Pressu- 4.97 l/ha 2.5 8 0 0.72 1.14 ND 0.004 0.027 0.034 9
(8) 1979 500 rized [935 Table 4 7 0.70 1.08 ND 0.003 0.028 0.043 9
Hand l/ha] 14 0.62 1.18 ND ND 0.014 0.021 9
Sprayer 8 0 0.95 2.68 ND ND 0.039 0.062 9
Table 5 7 0.77 1.09 ND ND 0.025 0.039 9
14 0.40 0.59 ND ND 0.016 0.022 9
Bravo Pressu- 3.36 2.5 8 0 0.70 0.91 ND ND 0.025 0.031 9
W-75 rized kg/ha Table 6 7 0.37 0.60 ND ND 0.026 0.042 9
Hand [935 14 0.37 0.57 ND ND 0.013 0.017 9
Sprayer l/ha]
TABLE 3 (con't)
RATE
FORMULA- NUMBER OF TREATMENT RESIDUES (PPM)1
TION AND APPLICA- TO
CROP PRODUCT APPLICA- [SPRAY ACTIVE TIONS, HARVEST CHLOROTHALONIL HCB PCBN NUMBER
AND LOCATION FORMU- TION VOLUME INGREDIENT TABLE IN INTERVAL HIGH HIGH HIGH SAMPLES
REFERENCE* AND YEAR LATION METHOD (L/HA)]** (KG/HA) REPORT (DAYS) MEAN VALUE MEAN VALUE MEAN VALUE ANALYZED
Tomatoes UN- -- -- -- Table 7 0 ND 0.01 ND ND 0.011 0.015 6
(8) TREATED 7 ND 0.01 ND ND 0.022 0.027 6
(con't) 14 ND ND ND ND 0.010 0.019 6
Florida Bravo Boom 4.97 l/ha 2.5 11 0 0.62 1.21 ND 0.003 0.035 0.044 9
500 Sprayer [374 Table 8 7 0.14 0.39 ND ND 0.025 0.030 9
l/ha] 14 0.03 0.05 ND 0.008 0.024 0.030 9
11 0 0.42 0.67 ND ND 0.036 0.078 9
Table 9 7 0.11 0.25 ND ND 0.033 0.040 9
14 0.04 0.18 ND ND 0.027 0.038 9
Bravo Boom 3.36 2.5 11 0 1.16 2.73 ND ND 0.036 0.053 9
W-75 Sprayer kg/ha Table 10 7 0.16 0.34 ND ND 0.021 0.030 9
[374 14 0.08 0.14 ND ND 0.029 0.034 6
l/ha]
UN- -- -- -- Table 11 0 ND 0.72 ND ND 0.022 0.028 6
TREATED 7 ND ND ND ND 0.024 0.029 6
14 ND ND ND ND 0.027 0.031 6
Indiana Bravo Boom 4.97 l/ha 2.5 6 0 3.54 5.28 ND 0.004 0.074 0.117 9
1979 500 Sprayer [702 Table 12 7 2.18 2.98 ND ND 0.040 0.057 9
l/ha] 14 1.36 2.45 ND ND 0.042 0.056 9
TABLE 3 (con't)
RATE
FORMULA- NUMBER OF TREATMENT RESIDUES (PPM)1
TION AND APPLICA- TO
CROP PRODUCT APPLICA- [SPRAY ACTIVE TIONS, HARVEST CHLOROTHALONIL HCB PCBN NUMBER
AND LOCATION FORMU- TION VOLUME INGREDIENT TABLE IN INTERVAL HIGH HIGH HIGH SAMPLES
REFERENCE* AND YEAR LATION METHOD (L/HA)]** (KG/HA) REPORT (DAYS) MEAN VALUE MEAN VALUE MEAN VALUE ANALYZED
Tomatoes Bravo Boom 3.36 2.5 6 0 1.34 3.76 ND ND 0.032 0.053 9
(8) W-75 Sprayer kg/ha Table 13 7 0.45 1.46 ND ND 0.018 0.025 9
(con't) [702 14 0.09 0.43 ND ND 0.021 0.026 9
l/ha]
UN- -- -- -- Table 14 0 ND ND ND ND 0.014 0.016 6
TREATED 7 0.09 0.30 ND ND 0.021 0.027 6
14 ND ND ND ND 0.023 0.028 6
Virginia Bravo Pressu- 4.97 l/ha 2.5 5 0 2.61 5.98 ND ND 0.046 0.070 9
1979 500 rized [468 Table 15 7 0.91 1.56 ND ND 0.017 0.029 9
Backpack l/ha] 14 0.40 1.19 ND ND 0.009 0.024 9
UN- -- -- -- Table 16 0 ND ND ND ND 0.014 0.020 6
TREATED 7 ND ND ND ND 0.019 0.021 6
14 ND ND ND ND 0.006 0.011 6
Florida Bravo Pressu- 4.97 l/ha 2.5 10 0 0.83 1.30 ND ND 0.012 0.017 3
1979 500 rized [935 Table 17
Hand l/ha]
Sprayer
UN- -- -- -- Table 18 0 ND ND ND ND 0.008 0.009 3
TREATED
TABLE 3 (con't)
RATE
FORMULA- NUMBER OF TREATMENT RESIDUES (PPM)1
TION AND APPLICA- TO
CROP PRODUCT APPLICA- [SPRAY ACTIVE TIONS, HARVEST CHLOROTHALONIL HCB PCBN NUMBER
AND LOCATION FORMU- TION VOLUME INGREDIENT TABLE IN INTERVAL HIGH HIGH HIGH SAMPLES
REFERENCE* AND YEAR LATION METHOD (L/HA)]** (KG/HA) REPORT (DAYS) MEAN VALUE MEAN VALUE MEAN VALUE ANALYZED
Tomatoes Michigan Bravo Sprink- 3.51 l/ha 1.75 10 0 2.13 3.06 ND ND 0.037 0.046 6
(9) 1979 500 ler [8418 Tables 7 1.65 2.18 ND ND 0.031 0.041 6
(con't) Irriga- l/ha] 1, 2 & 3 14 1.12 1.58 ND ND 0.028 0.035 6
tion
UN- -- -- -- Tables 0 ND ND ND ND ND 0.011 6
TREATED 1, 2 & 3 7 0.06 0.19 ND ND 0.011 0.022 6
14 0.03 0.17 ND ND 0.013 0.016 6
* See numbered references under Diamond Shamrock, 1981c.
** Spray volume in brackets.
1 ND = Not detectable: <0.01 ppm chlorothalonil; <0.003 ppm HCB; <0.005 ppm PCBN.
2 NA = Not available.
3 field trimmed to 14 inches according to good agricultural practice.
TABLE 4 SUMMARY OF RESIDUES OF CHLOROTHALONIL AND HCB FROM EUROPEAN FIELD TRALS
RESIDUES IN MG/KG
APPLICATION
NUMBER DAYS AFTER CHLOROTHALONIL HCB REPORT
CROP COUNTRY YEAR NO. KG A.I./HA FORMULATON SAMPLES TREATMENT TREATED CONTROL TREATED CONTROL NUMBER REFERENCE2
Potatoes Belgium 1980 6 (1 × 1.5 Bravo 500 11 7 0.01 <0.01 <0.004 <0.004 81/014 (3)
+
2 × 1.9 11 14 <0.01 <0.01 <0.004 <0.004 81/014 (3)
+
3 × 2.3) 11 29 <0.01 <0.01 <0.004 <0.004 81/014 (3)
Netherlands 1980 5 (1 × 1.5 Bravo 500 1 14 <0.01 <0.01 <0.003 <0.003 81/044 (3)
+ 1 28 <0.01 <0.01 <0.003 <0.003 81/044 (3)
2 × 1.6 1 41 <0.01 <0.01 <0.003 <0.003 81/044 (3)
+
2 × 1.8)
Sweden 1980 5 (2 × 1.1 Bravo 500 1 35 0.03 <0.01 <0.004 <0.004 81/023 (3)
+ 1 42 0.01 <0.01 <0.004 <0.004 81/025 (3)
3 × 1.5) 1 60 <0..01 <0.01 <0.004 <0.004 81/021 (3)
1 67 0.02 <0.01 <0.004 <0.004 81/027 (3)
Tomatoes W. Germany 1980 10 (2 × 1.4 Bravo 500 1 0 7.5 0.34 0.003 <0.003) 81/042 (2)
+ 1 2 4.7 - - 0.003 - - 81/042 (2)
8 × 1.8) 1 3 4.4 0.03 0.003 <0.003 81/042 (2)
1 4 4.4 - - 0.003 - - 81/042 (2)
1 6 2.4 0.05 0.003 <0.003 81/042 (2)
Netherlands 1980 10 (2 × 1.35 Bravo 500 1 0 1.6 <0.01 <0.003 <0.003 81/043 (2)
+ 1 1 2.1 0.01 <0.003 <0.003 81/043 (2)
8 × 1.8) 1 2 2.6 0.01 <0.003 <0.003 81/043 (2)
1 4 1.8 0.02 <0.003 <0.003 81/043 (2)
1 7 2.4 0.01 <0.003 <0.003 81/043 (2)
TABLE 4 (con't)
RESIDUES IN MG/KG
APPLICATION
NUMBER DAYS AFTER CHLOROTHALONIL HCB REPORT
CROP COUNTRY YEAR NO. KG A.I./HA FORMULATON SAMPLES TREATMENT TREATED CONTROL TREATED CONTROL NUMBER REFERENCE2
Summer Germany 1980
Wheat
grain 1 1.1 Bravo 500 i 60 <0.01 <0.01 <0.003 <0.003 81/041 (1)
1 1.1 Bravo 500 1 66 <0.01 <0.01 <0.003 <0.003 81/040 (1)
straw 1 1.1 Bravo 500 1 60 <0.01 <0.01 <0.003 <0.003 81/041 (1)
1 1.1 Bravo 500 1 66 <0.01 <0.01 <0.003 <0.003 81/040 (1)
Netherlands 1980
grain 1 1.0 Bravo 500 1 68 <0.01 <0.01 <0.004 <0.004 81/035 (1)
green 1 1.0 Bravo 500 1 0 14.8 0.28 <0.01 <0.01 81/035 (1)
ears 1 7 1.9 0.10 <0.01 <0.01 81/035 (1)
1 24 0.27 0.09 <0.01 <0.01 81/035 (1)
1 35 0.38 0.07 <0.01 <0.01 81/035 (1)
Winter Sweden 1980 1 1 Bravo 500F 1 81 <0.01 <0.01 <0.003 <0.003 81/036 (1)
Wheat 1 1.25 Bravo 500F 1 81 <0.01 - - <0.003 - - 81/036 (1)
1 1 Bravo 500F 1 76 <0.01 <0.01 <0.003 <0.003 81/037 (1)
1 1.25 Bravo 500F 1 76 <0.01 - - <0.003 - - 81/037 (1)
1 1 Bravo 500F 1 64 <0.01 <0.01 <0.003 <0.003 81/038 (1)
1 1.25 Bravo 500F 1 64 <0.01 - - <0.003 - - 81/038 (1)
1 1 Bravo 500F 1 68 <0.01 <0.01 <0.003 <0.003 81/039 (1)
1 1.25 Bravo 500F 1 68 <0.01 - - <0.003 - - 81/039 (1)
1 1 Bravo 500F 1 70 <0.01 <0.01 <0.004 <0.004 81/029 (1)
1 1.25 Bravo 500F 1 70 <0.01 - - <0.004 - - 81/029 (1)
1 4 replications, 1 sample, analyzed in duplicate; given residues are averages of duplicates.
2 See numbered items under Diamond Shamrock, 1981d.
TABLE 5. Residues of chlorothalonil resulting from supervised trials in the Netherlands
Crop or Year of Application Residues in mg/kg, at intervals Ref.**
situation trial (days) after (last) application*
Number Rate per
of treatment Formulation untreated 14 21 28
treatments kg a.i./ha
leaves 0.12 1.8 1
celeriac 1976 3 1.83 73% (0.11-0.13) (1.10-2.28)
blanched 0.11 2.2
celery 1977 2 1.83 73% (0.06-0.16) (1.47-2.77) 2
leek (white) 0.02 0.01 0.11 <0.01
part (<0.01-0.12) (<0.01-0.02) (0.07-0.16) (n.d.-0.02) 3
" (green) 1978 1.75 73% 0.26 0.81 2.67 0.37
" part (0.51-1.05) (1.25.-4.28 (0.35-0.38)
" (total) 0.09 0.28 0.94 0.13
(0.18-0.36) (0.46-1.50) (0.13-0.14)
leek (white) 0.06 0.03 <0.01
part (0.03-0.10) (0.02-0.04) (n.d.-0.01)
" (green) 1978 2.25 73% 5.93 4.22 0.42 3
part (3.02-786) (3.50-4.85) (0.07-0.64)
" (total) 2.02 1.42 0.14
(1.05-2.64) (1.20-1.63) (0.03-0.21)
leek (white) 0.02 0.02 0.04
part (0.01-0.03) (0.01-0.02) (n.d.-0.10)
" (green) 1978 1.75 73% 2.63 1.73 1.44 3
part (0.91-3.73) (0.73-2.44) (0.67-2.48)
0.91 0.59 0.51
" (total) (0.32-1.26) (0.25-0.83) (0.22-0.89)
TABLE 5. (con't)
Crop or Year of Application Residues in mg/kg, at intervals Ref.**
situation trial (days) after (last) application*
Number Rate per
of treatment Formulation untreated 14 21 28
treatments kg a.i./ha
10 days 16 days
strawberry 1980 4 1.5 50% 6.27 1.36 0.17 4
(+ 0.5 (+ 16,7% (4.83-7.08) (0.84-1.83)
vinchlozolin) vinchlozolin) 3 samples 3 samples
* Except for strawberries the number of samples was not provided, only the summary data in this table.
** References: see Netherlands, 1981.
generally expected to be less (only one of 36 treated was 0.003 mg/kg)
than the 0.003 mg/kg limit of determination and residues of PCBN may
be up to 0.06 mg/kg.
Chlorothalonil residues on celery from trials in The Netherlands
were well below the 15 mg/kg limit.
Cucumber
Maximum residues on or after the last day of up to eight
applications of Bravo 500 or Bravo W-75 at 2.5 kg a.i./ha, by three
modes of application were 1.43 mg/kg chlorothalonil, 0.005 mg/kg HCB
and 0.028 mg/kg PCBN. Maximum apparent residues on controls were
0.003 mg/kg HCB, 0.006 mg/kg chlorothalonil and 0.005 mg/kg PCBN.
Residues on day of last application (or later if residues are higher)
are the most pertinent to the one day after last application basis for
the current Codex 5 mg/kg temporary MRL.
These studies indicate that residues of chlorothalonil alone
resulting from the given rates (at or 0.7x the recommended rates on
celery for W-75 and Bravo 500, respectively) and modes of application
are well within the Codex temporary limit of 5 mg/kg. Residues of
PCBN may approach 0.03 mg/kg on occasion from these agricultural
practices. Residues of HCB were at or above the 0.003 mg/kg limit of
determination on only 4% of the 174 treated samples analysed (2.3%
were above). Residues in individual samples may occasionally be up to
0.005 mg/kg.
Leek
Summary data for chlorothalonil residue trials in The Netherlands
were provided. However, whether the applications represented good
agricultural practices in The Netherlands could not be determined
since the application rates used were in different units than the good
agricultural practice information provided. Neither the number of
applications nor the number of samples was provided. Maximum residues
at the 14-day PHI were 2.6 mg/kg. Because only summary data were
provided and other necessary information was lacking, a maximum limit
could not be estimated for leek.
Orange
When immature Valencia oranges were treated once in Florida by
mist blower, according to proposed uses at 2.93 to 4.1 kg a.i./ha with
Bravo 500, and harvested at normal harvest, maximum residues were
<0.01 mg/kg chlorothalonil, 0.003 mg/kg HCB and 0.021 mg/kg PCBN.
Only one of 44 samples (2%) gave higher HCB residues than those
found in untreated samples, and even that level was at the limit of
determination. The chlorothalonil residues are well below the Codex
temporary MRL of 5 mg/kg. Maximum apparent residues in controls were
<0.01 mg/kg chlorothalonil, < 0.003 mg/kg HCB and 0.019 mg/kg PCBN.
Sample analysis was performed after surface extraction, and this
approach was compared with maceration. As residues were mostly below
the sensitivity of this method, this comparison at best showed higher
background with maceration than with surface extraction. There were no
data on possible concentrations resulting from processing.
Potato
Studies were conducted in three states in the U.S.A. and in
three countries in Europe with up to nine applications at rates up to
2.3 kg a.i./ha. Samples were taken from zero to 67 days after last
treatment.
Maximum residues from the given conditions were 0.18 mg/kg
chlorothalonil, 0.004 mg/kg HCB and 0.008 mg/kg PCBN. When corrected
for controls, the 0.18 mg/kg value was said to be 0.1 mg/kg, which is
the Codex temporary MRL for potatoes. The Codex limit is based on the
interval between day of last application and harvest. Maximum apparent
residues in field trial controls were 0.02 mg/kg chlorothalonil,
<0.003 mg/kg HCB and <0.005 mg/kg PCBN.
Of the 54 analyses of U.S.A. samples harvested on day of last
application, four (7%) had HCB residues, > the 0.003 mg/kg limit of
determination and two (3.7%) were greater. Thus, while for the
majority of samples there was little difference between treated and
untreated, measurable residues of HCB and PCBN may occasionally be
found in individual samples created according to conditions in
Table 3.
Snap bean
Field trials were conducted in three states in the U.S.A. with up
to seven applications by hand or boom sprayer at proposed use rates of
2.5 kg a.i./ha as flowable or wettable powder formulation. About 132
treated samples were analysed from 10 studies.
Maximum residues were 3.65 mg/kg chlorothalonil, 0.014 mg/kg HCB
(composite of three replicates) and 0.08 mg/kg PCBN. There is a direct
correlation between residues of chlorothalonil and those of PCBN.
Maximum apparent residues in field trial controls were 0.13 mg/kg
chlorothalonil, 0.003 mg/kg HCB and 0.005 mg/kg PCBN.
After seven days from last application (the interval basis for
the Codex 5 mg/kg temporary limit) maximum residues were 3.04 mg/kg
chlorothalonil, 0.014 mg/kg HCB and 0.042 mg/kg PCBN. Only
three of the 132 treated samples (2.3%) had HCB residues the
> 0.003 mg/kg limit of determination and only the 0.014 mg/kg value
was greater.
Residues of chlorothalonil per se are therefore less than the
5 mg/kg Codex limit. Finite residues of PCBN can be expected up to
approximately 0.04 mg/kg from the given conditions of use and although
HCB residues are not normally greater on treated than untreated
samples, residues may occasionally exceed the 0.003 mg/kg limit of
determination.
Soybean
Field trials were conducted with two applications of flowable and
wettable powder formulations at or approximating proposed rates in six
geographic areas of the U.S.A., with harvest periods 40 to 57 days
after the last application. Several modes of application were used.
Maximum residues resulting from 56 treated samples from the six
geographical areas were 0.019 mg/kg chlorothalonil, 0.006 mg/kg HCB
and 0.024 mg/kg PCBN. Maximum field trial control samples were
0.039 mg/kg chlorothalonil, 0.006 mg/kg HCB and 0.024 mg/kg PCBN.
There is no significant difference between HCB and PCBN residues from
treated and untreated samples. Owing to relatively high apparent
residues in untreated samples, apparent residues above the normal
limits of determination may be encountered occasionally.
Strawberry
A limited amount of data were available for chlorothalonil
residues on strawberries. While these limited data indicate maximum
residues of 3-5 mg/kg at a proposed 14-day PHI, no information was
available on good agricultural practices. Data and information are
inadequate to estimate maximum residues.
Tomato
Field trials were conducted with flowable and wettable powder
formulations in five states in the U.S.A. and two European countries.
Up to 11 applications were made with rates up to 2.5 kg a.i./ha, with
harvests from 0 to 14 days after last application.
Analyses of 271 treated samples, as well as of untreated samples,
were made. Residues at day of last application were most comparable to
the one-day interval basis for the current 5 mg/kg Codex temporary
limit. Maximum residues on or after last day of application were
7.5 mg/kg chlorothalonil, 0.008 mg/kg HCB, and 0.117 PCBN. Maximum
apparent residues on untreated samples were 0.72 mg/kg, <0.003 mg/kg
and 0.031 mg/kg respectively. Only 10 (3.7%) of treated samples (U.S.
and European) gave HCB residues > the 0.003 mg/kg limit of
determination and only two (< 1%) had residues greater.
Residues of chlorothalonil alone were, for the most part,
consistent with the 5 mg/kg Codex limit. Even when corrected for
apparent background residues, a net residue was found for PCBN on all
treated tomatoes at zero day. Although there is little likelihood of
HCB residues in tomatoes from the uses and conditions specified,
residues on individual samples may occasionally exceed the 0.003 mg/kg
limit of determination.
Wheat
Residue studies were conducted in three European countries on
either summer or winter wheat. One application of 1 to 1.25 kg a.i./ha
chlorothalonil flowable formulation was made and harvesting done at
intervals ranging from 0 - 81 days after application.
Maximum residues on mature grain and straw on treated or
untreated samples were less than the 0.01 and 0.003 (or 0.004) mg/kg
limits of determination. The Codex 0.2 mg/kg temporary limit is based
on a six-week interval from last application to harvest.
Only "green ears" at 35 days or less after last application
contained chlorothalonil residue greater than the 0.2 mg/kg Codex
limit.
FATE OF RESIDUES
In storage and processing
The effects of simmering chlorothalonil in the presence of
green beans and tomatoes were investigated using open and covered
vessels (Diamond Shamrock 1981a). Fifty grams of chopped tomatoes or
green beans in 20 ml of water were fortified with approximately
1 000 000 dpm of 14C-chlorothalonil and simmered for 10 minutes in
both covered and uncovered vessels. The labelled chlorothalonil
fortification solution (10 000 dpm/µl) was prepared from phenyl-
labelled material of 99.2% purity and with a specific activity of
4.56 mCi/mmole.
On cooling, residues were extracted with acidified acetone,
concentrated, and partitioned with 1:1 petroleum ether: diethyl ether.
Appropriate aliquots of the organic and aqueous phases were
quantitated by liquid scintillation counting, including uncooked
controls, which demonstrated quantitative recoveries by the extraction
procedures. Results of the simmering studies are summarized in Table 6
for tomatoes and beans, respectively, for both covered and uncovered
vessels,
TABLE 6. Effect of simmering upon 14C-DS-2787 with tomatoes and green beans1
Recovery of 14C-Radioactivity(dpm)
Simmering 14C-DS.2787
Theoretically Organic Aqueous Loss
Condition Fortified (dpm) Ogase Phase Total (%)
Tomatoes
Without a 1 000 000 133 000 17 873 150 906 84.5
pot cover
With a pot 1 000 000 97 233 15 015 112 248 88.8
cover
Green beans
Without a 1 000 000 57 900 11 876 69 776 93
pot cover
With a pot 1 000 000 95 066 15 120 110 186 89
cover
1 Each recovery and loss is the average of three trials.
These results demonstrate that losses of chlorothalonil under
these conditions are 85-93% for tomatoes and beans and that there is
no significant difference in losses between covered or uncovered
vessels. Losses are apparently a result of volatilization - co-
distillation.
Because 14C-residues in the aqueous phase were low (generally
9-19% of residual activity) these were not characterized. The
14C-residues in the organic phase were characterized by thin layer
chromatography and autoradiography. Standards for comparison were
chlorothalonil (DS-2787), 4-hydroxy-2,5,6-trichloroisophthalonitrile
(DS-3701) and 3-cyano-2,4,5,6-tetrachlorobenzamide (DS-19221). The
migration of these standards was determined by UV viewbox.
Although quantification was not provided, the major residue in
the pot (in the organic phase) after simmering was said to be DS-2787
with negligible residues (again unquantified) of DS-3701. Unquantified
radioactivity near the origin of the thin layer chromatogram was
thought to be an artifact, as radioactivity was similarly found at the
origin of the standards and unsimmered control.
METHODS OF RESIDUE ANALYSIS
The analytical methods utilized for analysing samples from the
U.S.A. residue field trials are somewhat similar to methods previously
described (1974 Evaluations) for chlorothalonil, but modified for
determination of HCB and PCBN. Little information was provided on the
analytical methods used for the European studies.
In general, chopped samples were extracted by tumbling with
methylene chloride and concentrated. One aliquot was analysed on
electron capture gas chromatography. Another aliquot was
chromatographed on a florisil column for separation of HCB and PCBN
before analysis. In the case of oranges and soybeans, extraction was
by acetone and acetonitrile, respectively, and partitioning into
petroleum ether after acidification.
The methodology was validated on some (but not all) the
commodities to be as low as 0.02 mg/kg, 0.003 mg/kg and 0.02 mg/kg for
chlorothalonil, HCB and PCBN respectively. Validations for HCB were
all > 0.01 mg/kg, except for tomatoes, for which it was validated
at 0.003 mg/kg. Mean recoveries for all three compounds were generally
about 70% or better. Recoveries from snap beans and soybeans were
generally lower than for other commodities.
The methodology was considered by the manufacturer to be suitable
for quantitation down to 0.01 mg/kg, 0.003 mg/kg and 0.005 mg/kg
respectively, for chlorothalonil, HCB and PCBN. While this is
supported in general, control values are sometimes in excess of these
values, depending on the commodity.
The analytical methodologies for The Netherlands residue studies
were claimed to have a limit of determination of 0.05 mg/kg for
strawberries and a limit of detection of 0.01 to 0.02 mg/kg for
celery.
NATIONAL MAXIMUM RESIDUE LIMITS REPORTED TO THE MEETING
In addition to national maximum residue limits reported in
earlier monographs, there are now national MRLs as follows.
United States
Commodity Tolerances mg/kg*
Onions, dry bulb 0.5
Onions, green 5
Papayas 15
Passion fruit 3
Pumpkins 5
Soybeans 0.2
* U.S. tolerances include the metabolite 4-hydroxy-2,5,6-trichloro-
1,3-benzenedicarbonitrile.
Netherlands
Gherkin, celery 5
Cucumber, melon 1
Bulb, tuber and root vegetables 0.5
Mushroom 0.3
Wheat 0.2
Potatoes 0.05
Other food commodities 0.01
EVALUATION
COMMENTS AND APPRAISAL
A three-generation rat study with 4-hydroxy-2,5,6-trichloro-
isophthalonitrile (a metabolite known to be more acutely toxic than
chlorothalonil) permitted estimation of a no-effect dietary level of
10 ppm.
The extent of conversion of chlorothalonil to the metabolite
(which is included in the estimated ADI) is not known. In the absence
of adequate metabolic data, and of a reproduction study permitting
evaluation, on the parent compound, the Meeting had no alternative
other than to assume total conversion of chlorothalonil to the
metabolite. The no-effect level in the rat determined in 1974 was
therefore reduced.
Data from field trials designed to answer questions
on the possible occurrence of hexachlorobenzene (HCB) and
pentachlorobenzonitrile (PCBN) resulting from the use of wettable
powder and flowable formulations of chlorothalonil on a variety of
commodities have been evaluated. Also examined was a study designed to
answer questions on the nature and levels of residues resulting from
cooking of commodities containing chlorothalonil and additional
residue data and information on national tolerances and good
agricultural practices.
Field trials were conducted in the United States and European
countries on a variety of commodities treated at proposed rates with
flowable and wettable powder chlorothalonil formulations containing
measured amounts of HCB and PCBN impurities. The studies represented a
wide geographical distribution and utilized over six methods for up to
15 applications of formulation, depending on the commodity. More than
600 samples were analysed from over 40 studies.
At application rates used and at intervals after harvest
consistent with those used as a basis for current Codex temporary
limits (or under proposed use conditions), residues of chlorothalonil
per se are generally consistent with current Codex limits,
although analyses were not made for 4-hydroxy-2,5,6-trichloro-1,
3-benzenedicarbonitrile. This metabolite is included in the current
Codex temporary limits.
Under these same conditions of use and intervals following
application, low levels of PCBN residues did occur and were generally
correlated with the chlorothalonil residues. Maximum residues may
occur up to 0.08 mg/kg but are generally half of this or less on most
commodities. For most treated samples, residues of HCB were not
significantly different than those on untreated samples. However,
occasional residues (approximately 1-4%, depending on the commodity)
may be higher than the 0.003 mg/kg limit of determination of the
analytical procedure. Only in rare cases is the residue likely to
reach or exceed 0.01 mg/kg. Although the possibility of chlorothalonil
or its major metabolite occurring in some animal feed items (silage
and tomato pomace) has been considered previously, these items
apparently were not examined for possible residues of HCB or PCBN.
Also, it seems that dairy cattle tissue or milk samples were not
analysed for HCB or PCBN when feeding studies were conducted. The
potential for bio-accumulation of HCB and PCBN in animals from the use
of chlorothalonil apparently has not been addressed. Although levels
of these chemicals especially HCB, were shown to be relatively low on
the eight raw commodities examined, there is some possibility of bio-
accumulation, especially where crops are treated with chlorothalonil
in the same fields for several years or where processed products are
used as animal feeds.
Analytical methods used in the field trials were considered by
the manufacturer to be suitable for quantitation of chlorothalonil,
HCB and PCBN at levels of 0.01 mg/kg, 0.003 mg/kg and 0.005 mg/kg
respectively, although validation levels were generally higher and
background apparent residues can exceed these levels in specific
cases.
The analytical methods were validated on fortified samples and a
tumble extraction of chopped samples was utilised. It is not clear
whether these procedures quantitatively remove field incurred residues
or whether maceration techniques might be more efficient. Extraction
of chlorothalonil, HCB and PCBN by maceration was compared with tumble
extraction on field treated oranges, but residues were too low for
firm conclusions on relative extraction efficiencies. Also, residues
were not high enough to draw firm conclusions as intended on the
possibility of movement of residues from the peel into the fruit,
although earlier studies (1974 Evaluations) indicated that most of the
residue of chlorothalonil per se is on the surface of numerous
vegetables, with trace residues in the pulp of citrus. The Meeting was
informed that these studies had recently been repeated at higher
fortification levels.
An additional study submitted to this Meeting, in which
chlorothalonil fortified green beans and tomatoes were simmered in
loosely covered and uncovered vessels (Diamond Shamrock 1981a),
confirms results from earlier studies (Diamond Shamrock 1981b), which
show that under these experimental conditions, the majority of the
chlorothalonil is lost (over 85%), presumably to volatilization or co-
distillation. However, some results from these recent studies are
quantitatively somewhat different and even qualitatively inconsistent
in some respects with those of earlier similar open studies.
In the study submitted to this Meeting, chlorothalonil losses
from cooking tomatoes under open conditions were somewhat less than
previously (85% versus 98%) and in tomatoes and beans the
radioactivity in the aqueous phase of total residual activity is
somewhat less under open cooking conditions than previously (9 to 18%
versus 25 to 30%). Of more significance is the conclusion from the
more recent studies that the major residue in the organic phase from
open cooking (including cooking with a loose cover) of chlorothalonil
fortified tomatoes or beans is chlorothalonil, with negligible
hydrolysis to DS-3701. The earlier studies with open cooking of beans
(Diamond Shamrock 1981b) showed no residues of chlorothalonil (or
DS-19221) in the organic phase, but 57% of the radioactivity was
identified as DS-3701 and 43% was unidentified radioactivity near the
origin. Similar results were previously found under reflux conditions,
although 15% of the organic phase residue was chlorothalonil. There is
no known explanation for this apparent inconsistency between these
studies.
It was also observed that while the authors of the recent studies
considered unquantified radioactivity at the origin of the thin layer
chromatogram to be artifacts, unidentified near-origin residues of
radioactivity in the organic phase from the open cooking of beans in
the earlier studies amounted to 43% of the residual organic phase
radioactivity (1.7% of applied).
There are, therefore, uncertainties remaining as to the nature of
chlorothalonil degradation products resulting from the open cooking of
chlorothalonil in the presence of foods. Since samples in these
studies were fortified just prior to simmering, no firm conclusions
can yet be drawn with regard to the nature or quantity of residues
that may be present from the cooking of foods with field-incurred
residues.
Additional information on chlorothalonil residues and use
patterns for grapes were submitted in response to the request of the
1981 Codex Committee on Pesticide Residues (Report, Alinorm 82/83,
para. 93). However, because of late receipt, they must be reviewed at
a future meeting.
Level causing no toxicological effect
Rat: 10 ppm in the diet, equivalent to 0.5 mg/kg bw/day
Dog: 120 ppm in the diet, equivalent to 3 mg/kg bw/day
Estimate of temporary acceptable daily intake for man
0 - 0.005 mg/kg bw
RECOMMENDATIONS OF RESIDUE LIMITS
No changes in previous estimates of chlorothalonil residues are
required, and data and information are inadequate to estimate
additional limits.
FURTHER WORK OR INFORMATION
Required (by 1983)
1. Studies indicating the extent to which chlorothalonil is
metabolized to 4-hydroxy-2,5,6-trichloroisophthalonitrile in
non-ruminant mammals.
2. Studies of the relative toxicity of chlorothalonil and 4-hydroxy-
2,5,6-trichloroisophthalonitrile with respect to nephrotoxicity.
3. Submission of mutagenicity tests with chlorothalonil and with
4-hydroxy-2,5,6-trichloroisophthalonitrile.
Desirable
1. Analyses of chlorothalonil-treated animal feed items, processed
and unprocessed, for residues of PCBN, for example, bean and
peanut vines.
2. Information on possible PCBN residues in tissues and milk of
dairy cattle fed a diet containing chlorothalonil.
3. Results of recently completed studies on the efficiency of
"tumble extraction" of field-incurred residues of chlorothalonil,
HCB and PCBN.
4. Explanation of apparent inconsistencies in studies on the nature
of residues resulting from the cooking of chlorothalonil-treated
foods.
REFERENCES
Barry, T.L., Gretch, F.M. and Rosen, J.D. Identification of
1977 pentachloronitrobenzonitrile residues in field crops.
Bulletin of Environmental Contamination and Toxicology,
18: 691-696.
Diamond Shamrock. Toxicological reports submitted to the 1981 JMPR by
1980 Diamond Shamrock Corporation.(Unpublished)
Diamond Shamrock. Effect of simmering upon 2,4,5,6
1981a tetrachloroisophthalonitrile (chlorothalonil, DS-2787) with
vegetables. Document Number: 372-3EF-80-0004-001 (4/29/80).
Submitted to the 1981 JMPR by Diamond Shamrock Corporation.
1981b Effect of Cooking upon 2,4,5,6-tetrachloroisophthalonitrile
(chlorothalonil DS-2787) and 4-hydroxy-2.5.6-
trichloroisophthalonitrile (DS-3701) Document No. 238-3EF-
79-0058-001; 11/9/79), submitted to the 1981 JMPR by Diamond
Shamrock Corporation.
1981c Volume I, Part II - United States tests. Submitted to the
1981 JMPR by Diamond Shamrock Corporation
1) Residues of 2,4,5,6-tetrachloroisphthalonitrile
(chlorothalonil, DS-2787), Hexachlorobenzene (HCB) and
Pentachlorobenzonitrile (PCBN) on celery resulting from
broadcast application of formulated chlorothalonil (Document
No. 334-3CR-80-0137-001; 10/28/80)
2) Residues of 2,4,5,6-tetrachloroisophthalonitrile
(chlorothalonil, DS-2787), Hexachlorobenzene (HCB) and
Pentachlorobenzonitrile (PCBN) on cucumbers (Document No.
334-3CR-80-0156-001; 10/7/80)
3) Residues of 2,4,5,6-tetrachloroisophthalonitrile
(chlorothalonil, DS-2787), Hexachlorobenzene (HCB) and
Pentachlorobenzonitrile (PCBN) on cucumbers following field
application of BRAVO 500 by Sprinkler Irrigation (Document
No. 336-3CR-80-0181-001; 11/5/80)
4) Residues of 2,4,5,6-tetrachloroisophthalonitrile
(chlorothalonil, DS-2787), Hexachlorobenzene (HCB) and
Pentachlorobenzonitrile (PCBN) on oranges (Document No.
355-3CR-80-0067-001; 6/19/80)
5) Residues on 2,4,5,6-tetrachloroisophthalonitrile
(chlorothalonil, DS-2787), Hexachlorobenzene (HCB) and
Pentachlorobenzonitrile (HCBN) on potatoes (Document No.
334-3CR-81-0043-001; 5/15/81)
6) Residues of 2,4,5,6-tetrachloroisophthalonitrile
(chlorothalonil, DS-2787), Hexachlorobenzene (HCB) and
Pentachlorobenzonitrile (PCBN) on Snap Beans (Document No.
334-3CR-80-0143-001; 10/16/80)
7) Residues of 2,4,5,6-tetrachloroisophthalonitrile
(chlorothalonil, DS-2787), Hexachlorobenzene (HCB) and
Pentachlorobenzonitrile (PCBN) on Soybeans (Document No.
334-3CR-79-0113-001; 1/7/80)
8) Residues of 2,4,5-tetrachloroisophthalonitrile
(chlorothalonil, DS-2787), Hexachlorobenzene (HCB) and
Pentachlorobenzonitrile (PCBN) on tomatoes (Document No.
334-3CR-80-0051-001; 5/30/80)
9) Residues of 2,4,5,6-tetrachloroisophthalonitrile
(chlorothalonil, DS-2787), Hexachlorobenzene (HCB) and
Pentachlorobenzonitrile (PCBN) on tomatoes following field
application of BRAVO 500 by sprinkler application (Document
No. 336-3CR-80-0066-002; 6/19/80)
1981d Volume I, Part III, European Studies, submitted to the 1981
JMPR by Diamond Shamrock Corporation.
1) Residues of 2,4,5,6-tetrachloroisophthalonitrile
(chlorothalonil, DS-2787) and Hexachlorobenzene (HCB) on
cereals (Wheat)
- Wheat - Grain and Straw - Hohenaspe, West Germany. (Report
81/041; 2/27/81)
- Wheat Grain and Straw - Kleinkarback, West Germany.
(Report 81/040; 2/27/81)
- Wheat - Green ears and Grain - Zuidlaarderveen,
Netherlands. (Report 81/035; 2/2/81)
- Wheat - Grain - Pugerup, Sweden. (Report 81/036; 2/27/81)
- Wheat - Grain - Valstad, Sweden. (Report 81/037; 2/27/81)
- Wheat - Grain - Lundsgarden, Sweden. (Report 81/038;
2/27/81)
- Wheat - Grain - Svanerberg, Sweden. (Report 81/039;
2/27/81)
- Wheat - Grain - Pugerup, Sweden. (Report 81/029; 1/30/81)
2) Residues of 2,4,5,6-tetrachloroisophthalonitrile
(chlorothalonil, DS-2787) and Hexachlorobenzene (HCB) on
tomatoes.
- Tomato Fruit - Bonn, West Germany (Report 81/042; 2/27/81)
- Tomato Fruit - Haren, Netherlands (Report 81/043; 2/27/81)
3) Residues of 2,2,4,5,6-tetrachloroisophthalonitrile
(chlorothalonil, DS-2787) and Hexachlorobenzene (HCB) on
potatoes.
- Tubers and Soil - Libramont, Belgium. (Report 81/014;
1/28/81)
- Tubers and Soil - Haren, Netherlands, (Report 81/044;
2/27/81)
- Tubers - Lan, Skepparslov, Sweden. (Report 81/023;
1/29/81)
- Tubers - Alnarp, Sweden. (Report 81/025; 1/30/81)
- Tubers - Lan, Knivsta, Sweden. (Trt. 81/021; 1/18/81)
- Tubers - Lan, Eldsberga, Sweden. (Report 81/027; 1/30/81)
Netherlands. Residue data provided by The Netherlands Government.
1981 Sources for numbered references:
1) Residues of Chlorothalonil in the leaves of Celeriac, KVW
(Food Inspection Service, Amsterdam) 211/CvF/PD mrt 1979.
2) Residues of chlorothalonil in Blanched Celery, KvW
212/CvF/PD mrt in 1979.
3) Determination of Residual Levels of the Fungicide
Chlorothalonil in Sampled of Leek Received from AAgrunol,
Holland; Study Report No. 17, April, 1978, Diamond
Shamrock/Europe.
4) Pflanzenschutzmittel. Rückstände, BASF Report No.s 441 00 F
80/6E/9E; 441 00 F 80/10E-/13E and 441 00 F 80/1E, dated
September 9, 1980.
See Also:
Toxicological Abbreviations
Chlorothalonil (EHC 183, 1996)
Chlorothalonil (HSG 98, 1995)
Chlorothalonil (ICSC)
Chlorothalonil (WHO Pesticide Residues Series 4)
Chlorothalonil (Pesticide residues in food: 1977 evaluations)
Chlorothalonil (Pesticide residues in food: 1983 evaluations)
Chlorothalonil (Pesticide residues in food: 1985 evaluations Part II Toxicology)
Chlorothalonil (Pesticide residues in food: 1987 evaluations Part II Toxicology)
Chlorothalonil (Pesticide residues in food: 1990 evaluations Toxicology)
Chlorothalonil (Pesticide residues in food: 1992 evaluations Part II Toxicology)
Chlorothalonil (IARC Summary & Evaluation, Volume 30, 1983)
Chlorothalonil (IARC Summary & Evaluation, Volume 73, 1999)