PESTICIDE RESIDUES IN FOOD - 1982
Sponsored jointly by FAO and WHO
EVALUATIONS 1982
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, 23 November - 2 December 1982
Food and Agriculture Organization of the United Nations
Rome 1983
CYPERMETHRIN
Explanation
Cypermethrin was reviewed by the JMPR in 1979 and 19811/ and
MRLs were recommended on a wide range of crops and on meat and milk
products. Further data requested by the 1981 Meeting included residue
data on soybeans from trials carried out in the U.S. and on residues
in poultry and poultry products derived from feeding treated produce.
Data on these requested items, as well as those on a number of other
crops for which no MRL has yet been proposed, have been evaluated.
RESIDUES IN FOOD AND THEIR EVALUATION
USE PATTERN
Preharvest
Recommendations for use of cypermethrin on the crops not
previously evaluated by the JMPR, or for which additional data were
requested, are summarized in Table 1.
Where several applications become necessary due to pest pressure,
it is unlikely that the frequency of treatment would be more often
than twice a month.
RESIDUES RESULTING FROM SUPERVISED TRIALS
Soybeans
A series of trials were carried out in the U.S. using aerial
applications of 9-45 l/ha, or ground applications of 90-360 l/ha, and
a standard rate of 110 g a.i./ha.
1/ See Annex 2 for FAO and WHO documentation.
Table 1. Recommended Uses of Cypermethrin
Application Minimum Preharvest
Crops Pest Rate (g/ha) interval
Soybean (USA) Pseudoplusia includens 50 - 100 3-4 weeks
Trichoplusia ni
Anticarsia gemmatalis
Nezara viridula
Plattypena scabra
Epilachna verivestis
Heliothis armigera
Laphyma exigua
Leeks Acrolepia assectella 30 - 60 7 days
Phytobia cepae
Thrips tabaci
Onions (bulb) Acrolepia ascectella 38 - 70 3 days
Carrots Agrotis segetum 25 - 70 7 days
Turnips Auxoa nigricans
Swedes (Rutabagas)
Parsnips
Phaseolus spp. Sitona spp. 25 - 60 7 days
Aphis fabae
Viola spp.
Spinach Trialeurodes spp. 25 - 60 7 days
Black currant Nematus olfaciens 40
Pteronidea ribesii 25 g/ha low volume
Gooseberries Lygocoris pabulinus or 0.005% high 7-14 days
Aphis spp. volume
Sunflowers Desmoris constructus
Agrotis spp.
Euxoa spp.
Spodoptera spp. 75 7 days
Linseed Homoeosoma electellum
Thripidae
Agrotis ipsilon
Table 1. Recommended Uses of Cypermethrin
Application Minimum Preharvest
Crops Pest Rate (g/ha) interval
Groundnuts Aphis craccivora 75 7 days
Spodoptera spp.
Thripidae
Barley Macrosiphum avenae 25 - 50 4 weeks
Mushrooms Megaselia spp. 6 mg/m2 1-2 days
Sciara spp.
The trials encompassed a representative range of the southern and
mid-western soybean-growing states. With one exception, the treated
crops were harvested 21-31 days after the second spray application.
The residues data and trials details are summarized in Table 2 (Ussary
1982).
There was no obvious difference in the cypermethrin levels in the
beans at harvest following either ground or aerial application. In all
cases, the residue levels were less than the MRL of 0.05 mg/kg
recommended by the 1979 Meeting for soybean.
Leek
Typically, good agricultural practice requires the application of
30-60 g/ha and a minimum treatment to harvest interval of 7 days.
A trial was conducted in The Netherlands in 1981. A 10%
formulation was applied to four replicate plots at 30 g a.i./ha.
Samples of whole plants were taken from each plot for analysis at
intervals up to 14 days after spraying and the residues determined.
Cypermethrin levels of 0.17-0.21 mg/kg on the day of spraying declined
to 0.05-0.06 mg/kg after 7 days and to 0.02-0.04 mg/kg after 14 days.
Additional trials were carried out in Germany in which 3 applications
were made at 60 g/ha. The data are summarized in Table 3 (Swaine
et al 1982a; Shell Chimie S.A. 1979, 1980). Following recommended
treatments, residues of cypermethrin in leeks at 7 days after
treatment are likely to occur at a level exceeding 0.5 mg/kg.
Table 2. Cypermethrin Residues in Soybeans, U.S., 19811/
Interval Cypermethrin
Rate of Volume between Last Levels
Method of application of Spray Number of Application and Determined
Location application (g a.i./ha) (l/ha) Applications harvest (days) (mg/kg)
Georgia Aerial 110 45 2 24 ND
Missouri Aerial 110 27 2 21 0.01
Alabama Aerial 110 9 2 21 Trace (<0.01)
Alabama Aerial 110 9 2 21 ND
Louisiana Aerial 110 9 2 21 0.01
Missouri Aerial 110 45 2 31 0.01
Arkansas Aerial 110 9 1 30 0.02
Illinois Ground 110 180 2 21 0.01
Missouri Ground 110 90 2 29 0.04
Florida Ground 110 330 2 21 Trace (<0.01)
Maryland Ground 110 360 2 25 0.01
North Carolina Ground 110 250 2 1 0.01
Table 2. (con't)
Interval Cypermethrin
Rate of Volume between Last Levels
Method of application of Spray Number of Application and Determined
Location application (g a.i./ha) (l/ha) Applications harvest (days) (mg/kg)
South Dakota Ground 110 90 2 21 0.03
Minnesota Ground 110 245 2 21 0.02
1/ Following either ground or aerial applications of 36% EC formulations. All figures are corrected
for % recovery. ND means not detected, less than 0.01 mg/kg.
Bulb Onions
Residues data have been obtained from trials in Canada in which
applications up to the excessively high rate of 2 g/ha were used. In
all cases, in spite of the high rates sometimes employed, cypermethrin
was not found in the bulbs (limit of determination 0.01 mg/kg). These
trials and the resulting data are also included in Table 3 (Swaine
et al 1980d, 1981a)
Root and Tuber Vegetables
Residue experiments have been carried out on carrots in the U.K.,
Canada and Germany. Dose rates up to 7 g/ha were applied and as many
as 8 treatments were used. In all cases, residues were below
0.05 mg/kg, even at zero treatment to harvest interval.
Trials have also been carried out with parsnips and swedes in the
U.K. where application rates of 25 and 50 g/ha were used 48 and 5 days
prior to harvest. Residue levels in the roots were 0.01 mg/kg or less.
These trials are summarized in Table 4 (Swaine et al 1980a; Shell
Chimie S.A. 1980, 1981; Shell Research Ltd. 1981).
Spinach
Trials were conducted on spinach in Germany and the U.K., in
which cypermethrin was applied at 5 g/ha and also at the somewhat high
rate of 100 g/ha. A description of the trials and the results are
given in Table 5 (Swaine et al 1981c; Shell Chimie S.A. 1981). When
used according to good agricultural practice, cypermethrin is unlikely
to give rise to residue levels on spinach above 2 mg/kg.
Beans
Although the 1979 JMPR evaluated data for beans (Phaseolus),
these were only for dried beans without pods. Data are now available
for green Phaseolus beans in pod and Vicia beans without pod from
the trials summarized in Table 6 (Swaine et al 1981b; Shell Chimie
S.A. 1980, 1981; Shell Research Ltd. 1980).
Residue levels of cypermethrin in whole Phaseolus beans
(including pods) were all below 0.5 mg/kg following use of the product
as recommended.
Residues in Vicia beans, following removal from the pods as for
normal consumption, were below the limit of determination of
0.01 mg/kg one week or more after treatment.
Table 3. Cypermethrin Residues in Leeks and Onions
Dose Spray Applications Preharvest
Rate Rate Interval Residues
Crop Country Variety Formulation (g/ha) (l/ha) No. Interval (days) (mg/kg)
Leeks Netherlands Triomfator 10% EC 30 1 000 1 0 0.18,0.17,0.17,0.21
3 0.07,0.09,0.08,0.09
7 0.05,0.06,0.05,0.06
14 0.04,0.04,0.03,0.02
Leeks Germany Siegfried 10% EC 60 3 2 weeks 0 0.44
7 0.24
14 0.12
21 0.01
28 <0.01
60 3 2 weeks 0 0.60
7 0.39
14 0.03
21 0.02
28 <0.01
60 3 2 weeks 0 0.55
7 0.25
14 0.07
21 0.02
28 <0.01
Onion Canada Garnet 40% EC 70 450 4 2 weeks 7 <0.01,<0.01,<0.01,<0.01
Onion Canada Exporter 40% EC 50 450 7 10-12 days 3 0.05,0.08,0.07,0.06
7 <0.01,<0.01,<0.01,<0.01
Table 3. (cont'd)
Dose Spray Applications Preharvest
Rate Rate Interval Residues
Crop Country Variety Formulation (g/ha) (l/ha) No. Interval (days) (mg/kg)
Onion Canada 25% EC 35 250 1 64 <0.01
70 250 1 64 <0.01
70 340 1 10 <0.01
70 340 1 19 <0.01
140 340 1 10 <0.01
140 340 1 19 <0.01
280 340 1 10 <0.01
280 340 1 19 <0.01
Onion Canada 25% EC 200 250 1 60 <0.01
Table 4. Cypermethrin Residues in Root and Tuber Vegetables
Dose Spray Applications Preharvest Residues
Rate Rate Interval
Crop Country Variety Formulation (g/ha) (l/ha) No. Interval (days) (mg/kg)
Carrot UK Breeders 10% EC 25 600 1 48 0.01
Berjo 50 1 48 0.01
Carrot Canada Spartan 40% EC 50 450 7 9-13 days 3 <0.01,<0.01,<0.01,<0.01
Fancy <0.01,<0.01,<0.01,<0.01
Carrot Canada Spartan 40% EC 70 400 8 12-18 days 7 0.02
Fancy 14 0.03
Carrot Germany Nantaise 10% EC 60 500 3 2 weeks 0 <0.01
7 <0.01
14 <0.01
21 <0.01
Gonsenheimer 10% EC 60 500 3 2 weeks 0 0.02
7 <0.01
14 <0.01
21 <0.01
Hilds Fanal 10% EC 60 500 3 2 weeks 0 0.04
7 <0.01
14 <0.01
21 <0.01
Table 4. (con't)
Dose Spray Applications Preharvest Residues
Rate Rate Interval
Crop Country Variety Formulation (g/ha) (l/ha) No. Interval (days) (mg/kg)
Parsnip UK Alba 10% EC 25 600 1 48 <0.01
50 600 1 48 <0.01
Swede UK 10% EC 25 600 2 5 <0.01
50 600 2 5 0.01
Table 5. Cypermethrin Residues in Spinach
Dose Spray Applications Preharvest
Rate Rate Interval Interval Residues
Country Variety Formulation (g/ha) (l/ha) No. (weeks) (days) (mg/kg)
UK Bloomsdale 10% EC 100 500 1 0 5.7
3 1.8
7 1.2
14 0.19
Germany Monnopa 10% EC 60 500 3 2 0 0.79
7 0.13
14 0.05
21 <0.01
Monnopa 10% EC 60 500 3 2 0 2.00
7 0.49
14 0.10
21 0.01
Matares 10% EC 60 500 3 2 0 3.30
7 0.75
14 0.06
21 0.02
Table 6. Cypermethrin Residues in Beans
Dose Spray Applications Preharvest
Rate Rate Interval Residues
Crop Country Variety Formulation (g/ha) (l/ha) No. Interval (days) (mg/kg)
Dwarf U.K. Carousel 10% EC 25 260 1 0 0.16, 0.01
Beans 50 260 1 0 0.59
Kidney France Mangetout 5% EC 50 1 000 1 14 0.05
Beans
Green S. Africa Gallatin 20% EC 0.003% 700- 6 10-12 days 7 0.13
Beans 1 700 14 0.07
Green Fed. Rep. of
Beans Germany Perle v. 10% EC 60 3 2 weeks 0 0.75
Marbach 3 0.53
5 0.25
7 0.20
10 0.15
Weis Reising 10% EC 60 500 3 2 weeks 0 0.40
3 0.30
5 0.25
7 0.20
10 0.10
Table 6. (con't)
Dose Spray Applications Preharvest
Rate Rate Interval Residues
Crop Country Variety Formulation (g/ha) (l/ha) No. Interval (days) (mg/kg)
Green Fed. Rep. of
beans Germany Marga 10% EC 60 500 3 2 weeks 0 0.76
3 0.51
5 0.41
7 0.28
10 0.15
Pearle v. 10% EC 60 500 3 2 weeks 0 0.21
Marbach 3 0.15
(glasshouse) 5 0.12
7 0.14
10 0.11
Hild Neckar 10% EC 60 500 3 2 weeks 0 0.57
Konigin 3 0.50
5 0.30
7 0.24
10 0.15
Marga 10% EC 60 500 3 2 weeks 0 0.61
3 0.58
5 0.49
7 0.33
10 0.24
Broad U.K. Triple White 21 600 1 18 <0.01
Beans 21 600 2 8 days 10 <0.01
Field U.K. Maris Bead 25 500 1 0 0.09
Beans
Table 6. (con't)
Dose Spray Applications Preharvest
Rate Rate Interval Residues
Crop Country Variety Formulation (g/ha) (l/ha) No. Interval (days) (mg/kg)
Broad France 5% EC 50 1 000 1 8 <0.01
Beans 15 <0.01
31 <0.01
D'Aquadulce 5% EC 50 1 000 1 7 <0.01
13 <0.01
28 <0.01
Currants and Gooseberries
Residue trials were carried out in the U.K. on black currants and
gooseberries and in the Federal Republic of Germany on red currants.
These are summarized in Table 7 (Swaine et al 1980b; Shell Chimie
S.A. 1978, 1980; Shell Research Ltd. 1980). Cypermethrin residues in
the whole fruit did not exceed 0.5 mg/kg even on the day of treatment.
Oilseeds (Sunflowers and Linseed)
Details of experiments carried out on sunflower and linseed are
summarized in Table 8 (Sobolewski 1981; Shell Chimie 1981, 1982;
Robertson 1980; Shell Research Ltd. 1980). Trials with sunflowers have
been carried out in Australia, Argentina, Canada and South Africa
using a wide range of application rates. Residue levels observed in
seeds were all at or below 0.1 mg/kg, while those in whole heads were
below 0.2 mg/kg from normally recommended treatments.
Two trials on linseed were carried out in Canada using
28 g a.i./ha on up to 3 occasions with a minimum PHI of 4 weeks.
Residue levels reported were all 0.05 mg/kg or less.
Peanuts
Trials have been carried out in Canada, India and South Africa
using dose rates up to 100 g a.i./ha applied 7 days or more before
harvest. In no instance was residues found at a limit of determination
of 0.01 mg/kg (Table 9) (Shell Chimie S.A. 1980, 1981, 1982).
Barley
Residue experiments were carried out in Europe and Canada using
dose rates up to 62 g a.i./ha on 1 to 3 occasions. Residue levels in
whole (unhusked) barley grain from crops treated according to good
agricultural practice were all below 0.5 mg/kg where treatments were
made 3-4 weeks prior to harvest (Table 10) (Swaine et al 1980c,
1982d; Shell Research Ltd. 1981).
Mushrooms (Agaricus bisporus)
Cypermethrin is used as a spray, fog or smoke treatment in
mushroom houses. Because of the need to re-treat frequently and the
continuous cropping of mushrooms that takes place over an extended
period, an interval of 1-2 days between an application and cropping is
frequently necessary.
In a trial in The Netherlands in 1981, a 10% EC formulation was
applied twice at rates of 60, 120 and at the exceptionally high rate
of 240 g a.i./ha. Replicate samples of mushrooms were taken for
analysis 1, 2 and 3 days after the second spray. The cypermethrin
levels found are summarized in Table 10 (Swaine et al 1982b).
Table 7. Cypermethrin Residues in Currants and Gooseberries
Dose Spray Preharvest
Rate Rate Interval Residues
Crop Country Variety Formulation (g/ha) (l/ha) (days) (mg/kg)
Black
currant U.K. Baldwin 10% EC 25 1 100 0 0.18
25 1 100 1 0.13
25 1 100 3 0.15
25 1 100 7 0.12
25 1 100 14 0.07
50 1 100 7 0.23
Baldwin 25 1 100 7 0.11
50 1 100 7 0.10
Westwick 25 1 100 7 0.15
Choice 50 1 100 7 0.29
Black
currant U.K. Baldwin 10% EC 37.5 1 100 2 0.04
7 0.06
Black
currant U.K. Baldwin 10% EC 37.5 1 500 2 0.13
7 0.21
Red
currant1/ Fed. Rep. of
Germany Red Lake 10% EC 0.01% 1 500 0 0.40
7 0.35
14 0.29
21 0.20
Table 7. (con't)
Dose Spray Preharvest
Rate Rate Interval Residues
Crop Country Variety Formulation (g/ha) (l/ha) (days) (mg/kg)
Gooseberry U.K. Careless 5% EC 0.005% 24 0.03
Gooseberry U.K. Leveller 10% EC 25 1 100 7 0.13
25 1 100 7 0.05
25 560 9 0.09
50 1 100 7 0.21
50 1 100 7 0.12
1/ Two applications at an interval of 2 weeks. All others single applications.
Table 8. Cypermethrin Residues in Oilseeds
Spray Applications
Dose Rate Rate Preharvest Residues
Crop Country Variety Formulation (g/ha) (l/ha) No. Interval Interval (mg/g)
Sunflower Australia Cargill 25% EC 75 315 2 16 days 0 days 0.06
Seeds Sun Ace 84 7 days 0.10
14 days 0.04
21 days 0.03
100 315 2 16 days 0 days 0.07
7 days 0.05
14 days 0.05
21 days 0.04
200 315 2 16 days 0 days 0.14
84 7 days 0.15
14 days 0.11
21 days 0.08
Sunflower Australia Hysum 31 20% EC 75 50 1 1 day 0.32
Heads 7 days 0.18
13 days 0.04
20 days 0.03
75 50 1 1 day 0.41
7 days 0.12
13 days 0.03
20 days 0.02
Sunflower Argentina Empire 25% EC 50 11 1 17 days 0.04
Seeds
Table 8. (con't)
Spray Applications
Dose Rate Rate Preharvest Residues
Crop Country Variety Formulation (g/ha) (l/ha) No. Interval Interval (mg/g)
Sunflower Canada CSP8944 40% EC 14 118 1 10 weeks <0.01,<0.01,<0.01,<0.01
Seeds 20 118 1 10 weeks <0.01,<0.01,<0.01,<0.01
Sunflower Canada CMH103 40% EC 14 - 1 16 weeks <0.01,<0.01,<0.01,<0.01
Seeds 20 - 1 16 weeks <0.01,<0.01,<0.01,<0.01
16 weeks <0.01,<0.01,<0.01,<0.01
28 - 1
Sunflower S. Africa Sensako 20% EC 20 (by air) 1 1 day <0.01
seeds 5 days <0.01
8 days <0.01
12 days <0.01
26 days <0.01
Sensako 20% EC 30 (by air) 1 5 days <0.01
9 days <0.01
12 days <0.01
16 days <0.01
30 days <0.01
Table 8. (con't)
Spray Applications
Dose Rate Rate Preharvest Residues
Crop Country Variety Formulation (g/ha) (l/ha) No. Interval Interval (mg/g)
Linseed Canada Dufferin 40% EC 28 118 1 7 weeks <0.01,<0.01,<0.01,<0.01
(Seeds) 8 weeks <0.01,<0.01,<0.01,<0.01
12 weeks <0.01,<0.01,<0.01,0.01
Dufferin 40% EC 28 118 3 4 & 1 wk. 7 weeks 0.01,<0.01,0.01,0.02
Redwood 40% EC 28 118 1 4 weeks 0.04,0.05,0.05,0.02
6 weeks 0.02,0.02,0.03,0.03
10 weeks <0.01,<0.01,<0.01,<0.01
Redwood 40% EC 28 118 3 4 & 1,1/2 4 weeks 0.03,0.04,0.04,0.04
wks.
Table 9. Residues of Cypermethrin in Peanuts
Dose Spray Applications Preharvest Residues
Rate Rate
Country Variety Formulation (g/ha) (l/ha) No. Interval Interval (mg/kg)
Canada Valencia 40% EC 50 225 2 6 weeks 6 weeks <0.01,<0.01,<0.01,<0.01
India TMV-9 10% EC 50 500 1 13 days <0.01
20 days <0.01
27 days <0.01
100 500 1 13 days <0.01
20 days <0.01
27 days <0.01
TMV-7 10% EC 50 500 1 14 days <0.01
21 days <0.01
28 days <0.01
100 500 1 14 days <0.01
21 days <0.01
28 days <0.01
TMV-7 10% EC 50 500 1 2 weeks <0.01
3 weeks <0.01
4 weeks <0.01
100 500 1 2 weeks <0.01
3 weeks <0.01
4 weeks <0.01
Table 9 (con't)
Dose Spray Applications Preharvest Residues
Rate Rate
Country Variety Formulation (g/ha) (l/ha) No. Interval Interval (mg/kg)
S. Africa 20% EC 10 1 7 days <0.01
12 days <0.01
25 days <0.01
15 1 7 days <0.01
12 days <0.01
25 days <0.01
Table 10 Cypermethrin Residues in Barley Grain
Country Variety Formulation Dose Spray Applications Residues
Rate Rate Pre-harvest (mg/kg)
(g/ha) (l/ha) No. Interval Interval (days)
(days)
U.K. Sonya 10% EC 25 250 2 42 0.10
(Winter) 50 250 2 42 0.24
Sweden 6.25% 62.5 1 49 <0.01
Canada Klages 4% EC 28 118 1 26 0.22,0.30,0.27,0.22
42 0.13,0.15,0.12
66 <0.01,<0.01,<0.01,<0.01
28 118 3 24 & 16 26 0.47,0.37,0.27,0.51
Canada Bonanza 40% EC 28 118 1 25 0.08,0.16,0.16,0.18
32 0.11,0.16,0.16,0.08
48 0.03,0.02,0.04,0.03
28 118 3 16 & 7 25 0.25,0.25,0.22,0.16
Fed. Rep. of
Germany Aura 10% EC 50 500 1 48 0.02
Aura 10% EC 50 500 1 53 0.03
Table 11. Cypermethrin Residues in Mushrooms
Dose Spray Application Preharvest Residues
Crop Country Variety Formulation Rate Rate No. Interval (mg/kg)
(g/ha) (l/ha) (days)
Mushrooms Netherlands Somycel 53 10% EC 60 10 000 2 1 0.02,0.03
2 0.01,0.01
3 0.01,<0.01
120 10 000 2 1 0.04,0.04
2 0,02,0.02
3 0.01,<0.01
240 10 000 2 1 0.08,0.07
2 0.04,0.03
3 0.02,0.02
At the two lower rates, cypermethrin levels were consistently below
0.05 mg/kg in mushrooms sampled during the period 1-3 days after the
second application.
FATE OF RESIDUES
Data were reviewed by the 1979 Meeting on the fate of residues
during peeling, extraction, wine making, cooking and oilseed
processing. Additional data are now available on juice production,
cooking and oilseed processing and confirm the conclusions of the 1979
Meeting.
In Processing
Black currants containing weathered residues of cypermethrin were
processed through a laboratory simulation of the commercial process
whereby black currant juice is extracted. On average, less than 0.5%
of the original residue was transferred into the juice (Swaine
et al 1981d).
Cypermethrin levels in cabbage remained unchanged when samples
were boiled for 15 minutes. No cypermethrin was detected in the
water (limit of determination: 0.05 mg/kg) (Table 12) (Swaine
et al 1982c).
Table 12. Distribution of Cypermethrin Residues in Cabbage
before and after Boiling
Residue Fortification Total Residue Found (mg/kg)1
Sample (mg/kg) level Residue
(mg/kg) (mg/kg) Cabbage Water
1 0.02 1.0 1.02 1.03 0.05
2 0.02 1.0 1.02 1.03 0.05
3 0.02 1.0 1.02 1.03 0.05
1 Limit of determination: 0.01 mg/kg (cabbage); 0.05 mg/kg (water)
Two further cottonseed oil processing studies were conducted in
the U.S. In 1979, samples of cottonseed were collected from a field
trial 74 days after the last of eleven aerial applications of
cypermethrin at approximately 70 g a.i./ha. In 1980, samples were
collected 28 days after the last of seventeen aerial applications at
approximately 130 g a.i./ha. The seed was processed using commercial
type equipment. The whole cottonseed and each of the fractions
produced were analysed for residues of cypermethrin. The results are
shown in Table 13 (Ussary 1980, 1981).
Table 13 Cypermethrin Residues in Cottonseed Process Fractions,
U.S., 1979 and 1980
Process Fractions Cypermethrin Residues (mg/kg)1
I II III
Whole Cottonseed 0.017 0.031 0.035
Hulls 0.019 0.038 0.021
Solvent Extracted Meal 0.008 0.006 Trace(<0.01)
Crude Oil 0.15 0.20 0.16
Refined Oil 0.18 0.28 0.11
Refined, Bleached,
Deodorized Oil 0.16 0.13 0.061
Deodorized Distillates 0.025 0.033 Trace (<0.01)
Soapstock <0.01 <0.01 ND
1 All values corrected for analytical recovery.
ND = not detected, less than 0.01 mg/kg.
A sunflower seed oil processing study was conducted in Australia.
Samples of air-dried seeds were extracted with hexane. The oil was
refined and deodorized prior to analysis. Analysis of seed, oil and
cake for cypermethrin yielded results as shown in Table 14 (Sobolewski
1981). Residues in refined, deodorized oils are approximately twice
the levels found in the whole seed.
In Poultry and Poultry Products
Data on the nature and level of residues in meat and milk,
following oral administration of cypermethrin to cows, were reviewed
at the 1981 Meeting. Corresponding data are now available for eggs and
poultry meat.
Radiolabelled studies
In a radiolabelled study, 14C-phenoxy-labelled 55:45
cis-trans cypermethrin was administered orally to laying hens daily
for 14 days, at a rate equivalent to 10 ppm in the diet. Levels of
radioactivity in the eggs reached a plateau on the eighth day of
0.05 mg cypermethrin equivalents/kg, predominantly in the yolk. Of the
total residue in the yolk, approximately 30% was identified as
cypermethrin (of unchanged cis:trans isomer ratio) and a further 4%
was tentatively identified as trans-hydroxy-cypermethrin (I)
(Figure 1). The remainder of the radioactivity could not be separated
from the natural egg yolk lipids.
Table 14 Cypermethrin Residues in Sunflower Seed Processing Fractions, Australia, 1979-80
Applications Cypermethrin Residues (mg/kg)
Dose Rate Spray Rate Preharvest
(g/ha) (l/ha) Interval Interval Whole Seeds Oil Cake
No. (days) (days)
75 315 2 16 14 0.04 <0.01
84 21 0.03 0.04 <0.01
100 315 2 16 14 0.05 0.08 <0.01
84 21 0.04 0.09 <0.01
200 315 2 16 14 0.11 0.28 <0.01
84 21 0.08 0.17 <0.01
To examine residues in body tissues, the hens were sacrificed 4.5
hours after receiving the final dose, when levels of radioactivity in
tissues were as shown in Table 15. Of the tissues analysed, the liver
contained the highest levels of radioactivity (equivalent to a mean of
0.37 mg cypermethrin/kg). Of this, 0.06 mg/kg could be accounted for
as cypermethrin and 0.01 mg/kg as 3-phenoxybenzoic acid. Several polar
hepatic metabolites were present at levels equal to or less than that
of cypermethrin itself and could not be converted in measurable
quantities to either 3-phenoxybenzoic acid (IV) (3-PBA) or 4'-hydroxy-
3-phenoxybenzoic acid (V) (Figure 1). In body fat, total residues were
between 0.06 and 0.10 mg/kg. 56-59% of the radioactivity in peritoneal
and subcutaneous fat was due to unchanged cypermethrin. Residues in
breast and leg muscle, of 0.01-0.02 mg cypermethrin equivalents/kg,
were too small to facilitate characterization (Shell 1982).
Table 15. Residues of Radioactive Cypermethrin and/or its Metabolites in Tissues
of Laying Hens
Cypermethrin residues (mg/kg) in tissues from 4 birds
Tissue1 1 2 3 4 Mean S.D.
Fat (peritoneal) 0.11 0.07 0.09 0.06 0.08 (0.02)
Fat (subcutaneous) 0.10 0.08 0.06 0.08 0.08 (0.02)
Liver 0.41 0.34 0.41 0.32 0.37 (0.05)
Muscle (breast) 0.014 0.009 0.014 0.011 0.012 (0.002)
Muscle (leg) 0.024 0.016 0.025 0.015 0.022 (0.005)
1 Residues measured 4 hours after the last of 14 daily oral doses of
(14C-phenoxy-labelled) cypermethrin. Tissues of all birds measured in
triplicate, liver in quadruplicate.
These studies indicate that degradation of cypermethrin in hens
initially occurs primarily by hydrolysis of the ester link, leading
also to the formation of 3-(2,2-dichlorovinyl)-2, 2-dimethylcyclo-
propane carboxylic acid. Hence, in the unlabelled studies described
below, samples were analysed for this acid as well as for cypermethrin
and 3-PBA.
Non-labelled studies
In a study with 55:45 cis:trans cypermethrin, groups of 25
laying hens were fed diets containing 0.4, 4 and 40 ppm for 28 days
and then returned to a control diet for an additional 14 days. Samples
of eggs laid throughout the study were taken for residue analysis.
Groups of five hens were sacrificed after 21, 28, 35 and 42 days to
provide tissues for residue analysis.
Cypermethrin levels in the whole eggs reached a plateau after
approximately seven days of 0.05-0.09 mg/kg at the 40 ppm dietary
level. As predicted from the radiolabelled work, these residues were
present primarily in the yolk. On cessation of dosing, the levels
declined rapidly to below the limit of determination of 0.01 mg/kg.
Only very small levels of cypermethrin, up to 0.03 mg/kg, were
detected at the lower dietary rates. Residues of cis- and trans-3-
(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid (DCVA)
(II and III) and of 3-PBA (IV) were at or below the limit of
determination (0.01 mg/kg for whole eggs or 0.02 mg/kg for separated
yolks and albumin) (Table 16).
In the flesh, small residues of cypermethrin (up to 0.06 mg/kg)
occurred following the administration of a diet containing
cypermethrin at 40 ppm. These declined steadily to 0.02 mg/kg when
hens were returned to a normal diet. Small residues at the limit of
determination occurred at the lower dietary levels. Residue levels of
DCVA and 3-PBA did not exceed the limits of determination (0.02 mg/kg
and 0.01 mg/kg respectively) during the treatment period. Two weeks
after administration ceased no residues of DCVA or 3-PBA could be
found (Table 15).
Only very small residues of cypermethrin (up to 0.03 mg/kg) were
found in the liver of hens at the 4 and 40 ppm dietary rates. These
declined to the limit of determination (0.01 mg/kg) or less when the
hens were returned to an untreated diet. 3-PBA was just detected
(0.01 mg/kg) but only at the highest dietary rate, whereas DCVA was
present at up to 0.24 mg/kg at this rate and at about one tenth of
this level, 0.03 mg/kg, at the 4 ppm dietary rate. (These figures
refer to the 28-day feeding period.) This pattern of metabolite
residues is consistent with the radiolabelled work described above.
Residues of both metabolites fell rapidly to, or below, the limit of
determination (0.01 mg/kg) when the hens were returned to control diet
(Table 17) (Wallace and Roberts 1982).
APPRAISAL
Further extensive residues data on a number of crops are now
available. Those on soybeans arising from a request from the 1981
Joint Meeting confirmed the MRL of 0.05 mg/kg recommended by the 1979
Meeting.
Table 16 Residues of Cypermethrin and its Acid Metabolites in Whole Eggs1
Dose Compound Interval from Start of Feeding (days)
Rate Measured -3 -1 3 7 14 21 25 28 31 39 42
40 CPMT NA <0.01 0.03Y 0.05 0.18Y 0.04 0.03 0.09Y 0.03 <0.01 <0.01
<0.01W <0.01W <0.01W
4.0 " NA <0.01 <0.01Y <0.01 <0.01Y 0.01 <0.01 <0.01 0.01 <0.01 <0.01
<0.01W <0.01W
0.4 " NA NA <0.01Y <0.01 <0.01Y 0.01 0.02 0.03 0.02 <0.01 <0.01
<0.01W <0.01W
Control " NA NA <0.01Y <0.01 <0.01Y 0.01 <0.01 0.01 0.01 <0.01 <0.01
<0.01W <0.01W
40 DCVA <0.01 NA <0.02Y 0.01 <0.02Y 0.01 0.01 <0.02Y 0.01 <0.01 <0.01
<0.02W <0.02W <0.02W
4.0 " NA NA NA NA NA NA NA <0.01 NA NA NA
0.4 " NA NA NA NA NA NA NA NA NA NA NA
Control " NA NA <0.02Y NA NA NA NA NA NA NA NA
<0.02W
40 3-PBA 0.01 <0.01 <0.02Y 0.01 <0.02Y 0.01 0.01 <0.02Y 0.01 0.01 0.01
<0.02W <0.02W <0.02W
4.0 " NA NA NA NA NA NA NA 0.01 NA NA NA
0.4 " NA NA NA NA NA NA NA NA NA NA NA
Control " NA NA <0.02Y NA NA NA NA NA NA NA NA
<0.02W
1 Values in mg/kg unless stated otherwise; NA = not analysed; Y, egg yolk only; W,egg white only.
Table 17 Residues of Cypermethrin and its Acid Metabolites in Liver and Flesh
Liver (mg/kg) Flesh (mg/kg)
Dose Compound Interval from start of Interval from start of feeding
Rate Measured feeding (days) (days)
21 28 35 42 21 28 35 42
40 CMPT 0.03 0.021 <0.01 <0.01 0.062 0.041 0.03 0.02
4.0 " 0.01 0.03 <0.01 <0.01 0.012 0.01 0.012 <0.01
0.4 " 0.01 0.01 <0.01 0.01 0.022 0.012 0.012 0.012
Control " <0.01 <0.01 <0.01 0.01 <0.01 NA 0.012 NA
40 DCVA 0.21 0.241 0.03 0.01 <0.02 0.011 <0.02 <0.02
4.0 " 0.02 0.03 <0.01 0.01 <0.02 <0.02 <0.02 NA
0.4 " <0.01 NA3 NA NA <0.02 NA <0.02 NA
Control " <0.01 <0.01 NA <0.01 <0.02 NA <0.02 <0.02
40 3-PBA 0.01 <0.011 <0.01 <0.01 0.01 <0.011 0.01 <0.01
4.0 " <0.01 <0.01 <0.01 <0.01 0.02 <0.01 <0.01 NA
0.4 " <0.01 NA NA NA 0.02 NA 0.01 NA
Control " <0.01 <0.01 NA <0.01 0.02 NA 0.01 <0.01
1 Geometric mean of individual hen data;
2 Residues confirmed by GC/MS with single ion monitoring;
3 NA, not analysed.
Residues data from several supervised trials on barley, carrots,
kidney beans (with pod), currants, gooseberries, leeks, onions,
peanuts, parsnips, swedes, spinach, sunflower seed, linseed and
mushrooms enabled the Meeting to estimate maximum residue levels for
these crops. The Meeting proposed that, since MRLs had now been
recommended for all the major root and tuber vegetables at a level of
0.05 mg/kg, this figure could be extrapolated to the remaining members
of this commodity group and a group MRL of 0.05 mg/kg was recommended.
Similarly a group MRL for oilseeds, based on data on cottonseed,
rapeseed, sunflower seed and linseed, was recommended at 0.2 mg/kg.
Both radio-labelled and non-labelled studies on the nature and
level of residues in eggs and poultry meat were reviewed. Cypermethrin
levels in whole eggs reached a plateau level, after approximately
seven days, of 0.05 to 0.09 mg/kg at the 40 ppm dietary level (the
highest tested), the residues being mainly in the yolk. Levels
declined rapidly when dosing was stopped. The highest poultry flesh
levels recorded were 0.06 mg/kg during feeding a dose level of 40 ppm
in the diet.
In practice, it is unlikely that residues of parent compound or
metabolites will reach significant levels in eggs or poultry meat,
since dietary levels will seldom exceed 1 ppm in the poultry whole
diet for any appreciable period. The Meeting proposed an MRL of
0.05 mg/kg for eggs and poultry meat.
Further data on the effects of various methods of processing on
cypermethrin residues confirmed the conclusions of the 1979 Meeting.
Cypermethrin residues, being fat soluble, partition with fatty/oily
fractions and usually remain unchanged, even on cooking. The Meeting
estimated that the edible oil produced from vegetable oilseeds, as a
group, was not likely to contain more than 0.5 mg/kg of cypermethrin.
RECOMMENDATIONS
The Meeting concluded that the residue levels listed below are
suitable for establishing maximum residue limits. Attention is drawn
to two group MRLs, which replace the individual commodities in the
respective groups.
MRL (mg/kg)
Barley 0.5
Currants (black, red and white) 0.5
Gooseberries 0.5
Kidney beans (in pod) 0.5
Leeks 0.5
Mushrooms 0.05
Oilseeds 0.2
Onions 0.1
Peanuts 0.02
Root and tuber vegetables 0.05 (prev. potatoes
and sugarbeet)
Spinach 2
Eggs 0.05
Poultry meat 0.05
Edible vegetable oils 0.5
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(Unpublished)
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(Unpublished)
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raspberry and strawberry. UK, 1980. ICI Plant Protection
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1981. ICI Plant Protection Division Residue Data Report
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Plant Protection Division Residue Data Report. (Unpublished)
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(Unpublished)
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(Unpublished)
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See Also:
Toxicological Abbreviations
Cypermethrin (EHC 82, 1989)
Cypermethrin (HSG 22, 1989)
Cypermethrin (ICSC)
CYPERMETHRIN (JECFA Evaluation)
Cypermethrin (PIM 163)
Cypermethrin (Pesticide residues in food: 1981 evaluations)
Cypermethrin (Pesticide residues in food: 1983 evaluations)
Cypermethrin (Pesticide residues in food: 1984 evaluations)