WHO Pesticide Residues Series, No. 1
1971 EVALUATIONS OF SOME PESTICIDE RESIDUES IN FOOD
THE MONOGRAPHS
The evaluations contained in these monographs were prepared by the
Joint Meeting of the FAO Working Party of Experts on Pesticide
Residues and the WHO Expert Committee on Pesticide Residues that met
in Geneva from 22 to 29 November 1971.1
World Health Organization
Geneva
1972
1 Pesticide Residues in Food: Report of the 1971 Joint Meeting of
the FAO Working Party of Experts on Pesticide Residues and the WHO
Expert Committee on Pesticide Residues, Wld Hlth Org. techn. Rep.
Ser., No. 502; FAO Agricultural Studies, 1972, No. 88.
These monographs are also issued by the Food and Agriculture
Organization of the United Nations, Rome, as document AGP-1971/M/9/1.
FAO and WHO 1972
ENDOSULFAN
Since the previous evaluations (FAO/WHO, 1968, 1969), additional data
has become available and is summarized and discussed in the following
monograph addendum.
RESIDUES IN FOOD AND THEIR EVALUATION
Residues resulting from supervised trials
Recently-acquired data on residues of endosulfans A and B and
endosulfan sulfate (TS) in lettuce, cauliflower, and cabbage are
summarized in Table I. Endosulfan sulfate comprised 25-30% of the
total residue on lettuce and 25-50% of the total residue on cabbage.
Endosulfan B appears somewhat more persistent than A, sometimes
accounting for more than 50% of the total residue. Although the data
were somewhat erratic there was no indication of a build-up of
endosulfan sulfate in excess of the temporary tolerance of 2.0 ppm
(total residues) previously established by FAO/WHO (1969).
A summary of the results of field trials conducted by Hoechst at two
tea growing regions in India to determine residues in green tea, dry
manufactured tea, and aqueous tea infusions is given in Table III
(American Hoechst Corp., documents used in Food Additive Petition,
Thiodan on Tea, 12 August, 1971). Application rates of 0.5, 1, and 2
times the recommended rate of 2.5 litres of 35% E.C./hectare were
used, and residues of endosulfans A, B, and sulfate were determined
separately. The results show that total residues in dry tea leaves are
lower in samples grown in low elevations. The residues are only
slightly extracted from tea by hot water, yielding infusions
containing only a few micrograms per litre.
Endosulfan was applied to rice growing in the Philippines at 20 kg/ha
of 5% granular (three applications) and 2 1/ha of 35% EC (three
applications and four applications). Results of analysis for
endosulfans A and B and endosulfan sulfate in rice (peeled and
unpeeled), rice hulls, and rice straw harvested at two appropriate
intervals are presented in Table II (Hoechst, 1971).
FATE OF RESIDUES
In animals
Two dairy cows were fed endosulfan at 0.5 mg/kg body-weight daily
(12.5 mg/kg was attempted but resulted in the death of one cow), but
after two weeks the concentration in the milk was minimal and the dose
was increased to 1 mg/kg for two weeks more. The milk collected from
these two cows was manufactured into the dairy products, pasteurized
milk, cream, butter, spray-dried whole milk, condensed whole milk,
Cheddar cheese, and sterilized condensed milk and the by-products,
skim milk, buttermilk, and cheese whey. Analyses of the products
indicated only a very small concentration of endosulfan A. Endosulfan
TABLE 1. SUMMARY OF FIELD RESIDUE DATA FOR ENDOSULFAN (HOECHST PAPERS)
Total dose Days following Residue, ppma
active last
ingredient application A B TS Total
Lettuce 2.5 kg/ha 9 0.3 0.3 0.2 0.8
30 0.2 0.2 0.2 0.6
32 <0.05
43 0.2 0.1 0.1 0.4
0.02 kg/ha 20 1.17
28 0.335
35 0.096
42 0.000
Cauliflower 0.0525 g/plant 7 0.034 0.036 n.d. 0.07
14 0.020 0.024 n.d. 0.04
Cabbage 0.75 kg/ha 7 n.d.
14 n.d.
0.45 kg/hab 12 0.04 0.08 0.04 0.16
22 0.05 0.16 0.12 0.33
0.90 kg/ha 12 0.26 0.56 0.17 0.99
22 0.07 0.27 0.15 0.49
0.36 kg/ha 7 0.35 0.70 0.40 1.45
14 0.15 0.17 0.31 0.63
21 0.02 0.23 0.39 0.64
0.72 kg/ha 9 0.40 0.69 0.35 1.44
14 0.71 0.91 0.39 2.01
21 0.21 0.52 0.70 1.43
a A = Endosulfan A (alpha); B = Endosulfan B (beta); TS = Endosulfan sulfate;
n.d. = none detected.
b Calculated from dosages of 35% E.C. reported in fluid oz./ acre using the factors
1.745 g/cc. and 29.57 cc./fl.oz.
TABLE II. ENDOSULFAN RESIDUES IN RICE AND RICE STRAW FROM THE PHILIPPINES
Application Commodity Date of Residues in ppma
rate harvest A B TS Total
5% granularb peeled rice 5.2.71 nn nn nn nn
(20 kg/ha) 24.2.71 nn nn nn nn
TABLE II. (Continued)
Application Commodity Date of Residues in ppma
rate harvest A B TS Total
3 applications unpeeled rice 5.2.71 nn nn nn nn
24.2.71 nn nn 0.06 0.06
rice hulls 5.2.71 nn nn 0.04 0.04
rice straw 5.2.71 nn nn nn nn
24.2.71 0.30 0.83 1.82 2.95
35% ECc peeled rice 5.2.71 nn nn nn nn
(2 1/ha) 24.2.71 nn nn nn nn
3 applications unpeeled rice 5.2.71 nn nn nn nn
24.2.71 nn nn nn nn
rice hulls 5.2.71 0.47 0.61 0.66 1.71
24.2.71 nn nn nn nn
rice straw 5.2.71 0.07 0.17 0.19 0.43
24.2.71 0.10 0.34 0.44 0.88
35% ECc peeled rice 5.2.71 nn nn nn nn
(2 1/ha) 24.2.71 0.02 nn nn 0.02
4 applications unpeeled rice 5.2.71 nn nn 0.06 0.06
24.2.71 nn nn nn nn
rice hulls 24.2.71 nn nn nn nn
rice straw 5.2.71 0.21 0.29 1.11 2.21
24.2.71 0.04 0.30 0.51 0.85
a A = Endosulfan A; B = Endosulfan B; TS = Endosulfan sulfate; nn = none detected.
b Granular, last treatment date, 7 January 1971.
c EC = emulsifiable concentrate, last treatment date, 27 January 1971.
sulfate, which should have been the major residue present, was not
determined (Li et al. 1970).
In plants
Shuttleworth et al. (1971) studied the effects of sugar beet
processing to determine if endosulfan or endosulfan sulfate residues
in sugar beet roots would concentrate in the processed beet pulp.
Mature sugar beet root samples from a plot treated with three aerial
applications of Thiodan 2 EC at 1.0 lb active/acre were analysed 0 and
35 days after the last application. No endosulfan or endosulfan
sulfate residues were found at the limit of sensitivity of the method
of 0.05 ppm. Sugar beet pulp, obtained from processing the above
TABLE III. ENDOSULFAN RESIDUES IN TEA AND TEA INFUSION
Rate Pre-harvest Maximum residues, ppm
l/ha interval, days Dry manufactured teaa Tea infusiona
A B TS Totald A B TS Totald
2.5(×) 1 5.0 15 5.6 25.6 0.0034 0.020 0.0070 0.0299
2 2.8 9.6 5.9 18.1 0.0014 0.0083 0.0095 0.0168
4 1.4 3.3 4.3 8.4 0.00086 0.0020 0.0036 0.0065
7 2.4 0.8 1.0 4.2 0.00043 0.00027 0.0012 0.0019
5.0(2×) 1 2.6 73 11 108 0.0095 0.093 0.0085 0.1110
2 6.5 27 9.2 43 0.0018 0.023 0.0070 0.0317
4 1.0 4.4 3.6 9.0 0.0061 0.0050 0.0045 0.0156
7 0.25 0.7 1.4 2.3 0.00032 0.00030 0.0015 0.0019
(From 5000 ft elevation) Dry green teaa Green tea infusionb
1.25(1/2×) 1 12 20 6.1 38 0.007 0.014 0.020 0.041
7 2.9 12 9.2 24
15 n.d. 0.5 3.4 3.9
2.50(×) 1 19 25 10 50 0.024 0.052 0.025 0.101
7 1.7 4.7 7.2 14
15 0.9 2.4 2.6 5.3
(From 3000 ft elevation)
1.25(1/2×) 1 1.4 2.2 0.6 4.2 0.004 0.01 n.d. 0.014
7 n.d. 0.9 4.0 4.9 n.d. 0.003 n.d. 0.003
15 n.d. n.d. 0.8 0.8 n.d. n.d. n.d. n.d.
2.50(×) 1 4.8 13 4.6 18 n.d 0.002 0.011 0.013
7 0.3 1.6 3.8 4.7 0.001 0.004 0.011 0.016
15 n.d. n.d. 0.8 0.8 n.d. n.d. 0.006 0.006
TABLE III (Continued)
Rate Pre-harvest Maximum residues, ppm
l/ha interval, days Dry manufactured teaa Tea infusiona
A B TS Totald A B TS Totald
(From 5000 ft elevation Dry manufactured tea Tea infusion
1.25(1/2×) 1 10 20 6.4 36 0.011 0.045 0.030 0.086
7 0.7 4.1 7.9 13
15 0.1 0.3 2.9 3.3
2.5(×) 1 28 45 11 84 0.031 0.055 0.021 0.107
7 2.2 6.1 6.5 15
15 0.6 2.0 7.3 9.9
(From 3000 ft elevation)
1.25(1/2×) 1 3.4 9.8 2.4 16 0.007 0.024 0.012 0.043
7 1.3 9.0 5.8 16
15 n.d. 0.3 1.4 1.6
2.50(×) 1 10 16 3.6 30
7 5.4 22 7.6 35 0.001 0.004 0.009 0.014
15 1.4 3.8 6 2 11
a Three replications.
b Two replications.
c One sample only.
d A = Endosulfan A, B = Endosulfan B, TS = Endosulfan sulfate.
Total = maximum total of the replications, not necessarily the sum of the preceding A, B and TS columns.
beets, was analysed and no residues of endosulfan or endosulfan
sulfate were found at a sensitivity limit of 0.1 ppm.
Thiodan 2 EC was applied to cotton by aerial spraying at 1.0 and 3.0
(excess) lb active/acre/application for five applications each and
both plots were harvested nine days after the final application. The
cotton was ginned and the seed processed into meal, oil, etc. Residues
found in the various processed products are summarized in Table IV.
Overall recoveries were 90% for endosulfans A and B and 73% for
endosulfan sulfate. However, a material balance of 96.2% was achieved
for the 3 lb rate whereas a balance of only 60.5% was obtained for the
1 lb rate (Hinstridge, 1969).
TABLE IV. ENDOSULFAN RESIDUES IN COTTON PRODUCTS.
ALL PLOTS RECEIVED FIVE APPLICATIONS AND WERE HARVESTED NINE DAYS
AFTER FINAL APPLICATION
Product Rate Maximum residues, ppm
lb a.i. Endosulfan Sulfate Total
/acre/appl. A and B
Ginned seeda 1 0.20 0.05 0.25
3 0.80 0.36 1.16
Linters 1 0.29 n.d. 0.29
3 2.8 n.d. 2.8
Linter motes 1 2.4 1.19 3.6
3 15.2 4.2 19.5
Hullsa 1 0.04 n.d. 0.04
3 1.00 0.10 1.10
Meala 1 0.04 n.d. 0.04
3 n.d. n.d. n.d.
Crude oil 1 0.13 0.03 0.16
3 0.24 0.04 0.28
Refined oil 1 n.d. n.d. n.d.
3 0.14 0.03 0.17
Soap stock 1 0.02 n.d. 0.02
3 0.06 n.d. 0.06
a Maximum of four replications; all others are maximum of two
replications except soap stock, one replication.
Evidence of residues in food in commerce or at consumption
Endosulfan residues were determined in a total diet sample collected
in the Federal Republic of Germany. Food samples were collected in a
supermarket in the Frankfurt area in accord with directions published
by FAO/WHO and subjected to cooking or other normal home processing
operations preparatory to consumption. No residues of endosulfan A or
B or endosulfan sulfate were detectable in the food at analytical
sensitivity limits of <0.001 ppm for food groups I-V and VIII-IX and
<0,005 ppm for food groups VI and VII (Hoechst Report No. 95/68,
29 October 1968).
The results of total diet studies in the United States for the periods
June 1967 - April 1968 and June 1968 - April 1969 were reported by
Corneliussen (1969, 1970). Endosulfan (total) was found in three of
the 360 composites in the 1967-1968 survey; once in leafy vegetables
at 0.014 ppm, once in garden fruits at 0.008 ppm, and once in oils,
fats, and shortening at 0.134 ppm. In the 1968-1969 survey, endosulfan
was found in 16 of the 360 composites. Eight composites of leafy
vegetables contained total endosulfan residues ranging from a trace
to 0.042 ppm (average 0.012 ppm). Two composites of potatoes
contained residues of endosulfan sulfate of 0.004 and 0.011 ppm. Four
composites of garden fruits contained total endosulfan residues
ranging from a trace to 0.007 ppm (average 0.002 ppm) and two
composites of fruits contained 0.002 and 0.010 PPM. Processing of
leafy vegetables by a dietician resulted in a retention of 55% of
total endosulfan residues.
The calculated daily intake of total endosulfan residues in the United
States of America for the period June 1966 to April 1968 has been
given by Duggan (1969) as a trace in each of the three categories
- leafy vegetables, garden fruits, and oils, fats, and shortening.
METHODS OF RESIDUE ANALYSIS
No interlaboratory collaborative study of a multidetection method of
analysis as applied to endosulfan has been published since the last
re-evaluation. However, an analytical method for determining
endosulfan A and B isomers and endosulfan sulfate residues in and on
vegetable material has been developed by Hoechst (1966). The method
differs from most multidetection schemes in that the crushed sample is
extracted cold with a mixture of benzene and isopropanal (2:1). The
isopropanol is separated by shaking the mixture with a 2% sodium
chloride solution and the endosulfans remaining in the benzene phase
are determined by gas chromatography with a microcoulometer or
electron capture detector. If necessary, further clean-up may be
achieved by (a) treatment of the benzene extract with attapulgite
clay/carbon; (b) acetonitrile/hexane partitioning; or (c) by means of
thin layer chromatography. The recovery of the method is generally
80% ± 10% unless TLC has been used in which case it may fall to 70%.
The limit of detection in favourable cases is 0.002 mg/kg.
Samples containing high sugar contents (up to 20%) such as sugar beet
roots and sugar beet pulp may give erroneously high recoveries if
acetonitrile/water extraction Procedures are used. In these cases a
method developed by Niagara Chemical Division of FMC Corporation
(Shuttleworth et al. 1971) may be used. Acetonitrileisopropanol
(2:1 v/v) maceration is used for sugar beet roots while sugar beet
pulp is extracted with 35% v/v water-acetonitrile. After clean-up
using a Florisil(R) column, residues are determined by gas
chromatography with microcoulometric detection. The limit of detection
of the method is 0.05 ppm.
Endosulfans A and B and endosulfan sulfate may be selectively
determined by gas chromatography with a flame photometric detector
operated in the sulfur mode as reported by Bowman et al. (1970).
Extraction procedures for multicomponent residue analysis of 39
representative foods utilizing the preceding determinative step have
also been described by Bowman, et al. (1971).
Appraisal
Data from supervised trials on lettuce, cauliflower, and cabbage
indicate that endosulfan sulfate may comprise 25 to 50% of the total
weathered residue with endosulfan B usually making up the majority of
the remainder. There was no evidence to suggest that inclusion of
endosulfan sulfate in the total residue would require a revision of
the tolerance of 2 ppm for fruits and vegetables.
Extensive data from field trials on tea indicate that applications of
endosulfan in accord with good agricultural practice could result in
occasional total residues of 35 ppm (range 6.8 - 35 ppm; average 17
ppm) in the dry manufactured (black) tea picked seven days after
treatment. In practice this residue level would be highly unlikely
since only portions of a tea plantation would be treated at one time
and extensive blending of treated and untreated tea leaves would
occur. Since tea is brewed with water to make an infusion and the
extractability of endosulfan residues is normally quite low, residues
reaching the consumer would rarely exceed 0.08 ppm.
No measurable residues (<0.1 ppm) were found in sugar beet pulp
obtained from beets treated aerially at 1 lb a.i./acre.
Limited data on residues of total endosulfans on rice (peeled and
unpeeled), rice hulls, and rice straw indicate that residues in peeled
rice would be below the level of detection (<0.01 ppm) and in
unpeeled rice would not be greater than 0.06 ppm.
Application of endosulfan to cotton at 1 lb a.i./acre/application for
five applications resulted in average total endosulfan residues in the
ginned cottonseed of 0.20 ppm and in the crude cottonseed oil of 0.15
ppm. Refined cottonseed oil contained no detectable residues (<0.03
ppm).
EXAMPLES OF NATIONAL TOLERANCES
Country Tolerance Crop
ppm
United States 2 apples, apricots, artichokes,
of America beans, beans (dry), broccoli,
brussels sprouts, cabbage,
cauliflower, celery, cherries,
collards, cucumbers, eggplants,
grapes, kale, lettuce,
melons, mustard greens,
nectarines, peaches, pears,
peas, peppers, pineapples,
plums, prunes, pumpkins,
southern peas, spinach, squash,
strawberries, sunflower seed,
tomatoes, turnip greens, watercress
1 alfalfa hay, cottonseed
0.5 milk fat, sugarcane
0.2 meat, fat, and meat byproducts
of cattle, goats, hogs, horses,
and sheep, carrots, sweet corn
(kernels plus cob), filberts,
macadamia nuts, pecans, potatoes,
safflower seed, sweet-potatoes, walnuts
Total diet samples collected in Germany did not contain measurable
residues (<0.001 ppm) of endosulfan. In the United States of America,
total diet samples collected in 1968 and 1969 revealed an increase in
the incidence of total endosulfan residues in the latter survey
period. In 1968, endosulfan residues (range, 0.008-0.134 ppm) were
found in only three out of 360 composites while in 1969, 16 out of 360
composites contained endosulfan residues ranging from a trace to 0.042
ppm. Preparation by a dietician of leafy vegetables for consumption
resulted in retention of 55% of total endosulfan residues.
Adequate and selective methods of analysis for residues of endosulfan
A, endosulfan B, and endosulfan sulfate in fruits, vegetables, dry
tea, rice, cottonseed, and cottonseed oil are available. Special
extraction procedures for samples of high sugar content have been
developed.
RECOMMENDATIONS FOR TOLERANCES, TEMPORARY TOLERANCES OR PRACTICAL
RESIDUE LIMITS
Tolerances
Tea (dry, manufactured) 30 ppm
Fruits and vegetables 2 ppm
Cottonseed 0.5 ppm
Cottonseed oil (crude) 0.2 ppm
Rice (unpeeled) 0.1 ppm
The residues of endosulfan A, endosulfan B, and endosulfan sulfate are
to be determined individually but expressed as their sum.
The above tolerances are to apply to raw agricultural products moving
in commerce unless otherwise indicated. In the case of fruit and
vegetables the tolerances should be applied as soon as practicable
after harvest and in any event prior to actual retail to the public.
FURTHER WORK OR INFORMATION
Desirable
1. Metabolic studies in man, with particular reference to storage of
the original compound and metabolites (see FAO/WHO, 1969).
2. Further data on residue levels in rice.
3. Information on the latest use patterns of endosulfan, especially
on the specific fruits and vegetables to which it is applied in
various countries.
REFERENCES
Bowman, M. C., and Beroza, M. (1970) GLC retention times of pesticides
and metabolites containing phosphorus and sulfur on four thermally
stable columns. J. Assoc. Off. Anal. Chem. 53(3), 499-508
Bowman, M. C., Beroza, M., and Hill, K. R. (1971) Chromatograms of
foods for multicomponent residue determination of pesticides
containing phosphorus and/or sulfur by GLC with flame photometric
detection. J. Assoc. Off. Anal. Chem. 54(2), 346-358
Corneliussen, P. E. (1969) Pesticide residues in total diet samples
(IV). Pesticides Monit. J. 2(4), 140-152
Corneliussen, P. E. (1970) Pesticide residues in total diet samples M.
Pesticides Monit. J. 4(3), 89-105
Duggan, R. E., and Lipscomb, G. Q. (1969) Dietary intake of pesticide
chemicals in the United States (II), Pesticides Monit. J. 2(4),
153-162
FAO/WHO. (1968) 1967 Evaluations of some pesticide residues in food.
(FAO/PL:1967/M/11/1; WHO/FOOD ADD./68.30)
FAO/WHO. (1969) 1968 Evaluations of some pesticide residues in food.
(FAO/PL:1968/M/9/1; WHO/FOOD ADD./69.35)
Hinstridge, P.A. (1969) Thiodan (Residues on cottonseed - process
study). Project No. 015, Report No. R-1133, Niagara Chemical Division,
FMC Corporation, Research and Development, Richmond, California 94802
Hoechst. (1966) Farbwerke Hoechst AG, Analytical method for
determining Thiodan(R) residues in and on vegetable material,
Analytical Laboratory, Dr Gorbach, Report No. 65/66 E
Hoechst. (1968) Farbwerke Hoechst AG, Endosulfan residues in a total
diet sample collected in the Federal Republic of Germany. Analytical
Laboratory, Dr Gorbach, Report No. 95/68
Hoechst. (1969) Farbwerke Hoechst AG, Endosulfan on/in lettuce,
Analysis report, Analytical Laboratory
Hoechst. (1971) Hoechst Belgium SA, Endosulfan on/in lettuce, Analysis
report
Hoechst. (1971) Hoechst-Holland NV, Endosulfan on/in cauliflower,
Analysis report
Hoechst-Holland NV, Endosulfan on/in red cabbage, Analysis report
Farbwerke Hoechst AG, Endosulfan on/in cabbage, Analysis reports,
Sample No. 24, 25, 26, 27, 101, 102, 103, 104, 105, 106, Analytical
Laboratory
American Hoechst Corp., Food Additive Petition, Thiodan on Tea,
Experimental and Residue Data, Exhibit C-10: Tocklai, Assam, Northeast
India; Exhibit C-12: United Planters Assoc., Southern India Tea
Research Station, Cinchona, Coimbatore
Farbwerke Hoechst, AG, Residues of Endosulfan and Endosulfan Sulfate
on Rice and Rice Straw from the Philippines, Analysis Report
Li, C. F., Bradley, R. L. jr., and Schultz, L. H. (1970) Fate of
organo-chlorine pesticides during processing of milk into dairy
products. J. Assoc. Off. Anal. Chem. 53(1), 127-139
Shuttleworth, J. M. (1971) Determination of endosulfan and endosulfan
sulfate residues in sugar beet roots and sugar beet pulp. Project No.
015, Report No. M-2866, Niagara Chemical Division, FMC Corporation
Research and Development, Richmond, California 94802
See Also:
Toxicological Abbreviations
Endosulfan (EHC 40, 1984)
Endosulfan (HSG 17, 1988)
Endosulfan (PIM 576)
Endosulfan (FAO Meeting Report PL/1965/10/1)
Endosulfan (FAO/PL:1967/M/11/1)
Endosulfan (FAO/PL:1968/M/9/1)
Endosulfan (WHO Pesticide Residues Series 4)
Endosulfan (WHO Pesticide Residues Series 5)
Endosulfan (Pesticide residues in food: 1982 evaluations)
Endosulfan (Pesticide residues in food: 1989 evaluations Part II Toxicology)
Endosulfan (JMPR Evaluations 1998 Part II Toxicological)