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    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


    DELTAMETHRIN

    CHEMICAL STRUCTURE 1

    Explanation

         In 1980 the JMPR reviewed deltamethrin (FAO/WHO 1981)1/, and
    determined that an ADI could not be estimated without further
    information. Additional data were received and reviewed by the JMPR in
    1981 (2-year feeding study in dogs; 2-year mouse oncogenicity study;
    mouse and rat teratology studies; additional mutagenicity evaluations
    and information on humans). No ADI was estimated. Since then,
    additional data has been submitted to FAO/WHO and are reviewed in this
    monograph addendum.

    EVALUATION FOR ACCEPTABLE DAILY INTAKE

    TOXICOLOGICAL STUDIES

    Special Study for Carcinogenicity

         Studies designed to investigate the potential carcinogenic
    effects of deltamethrin have been initiated by IARC.

         Groups of BDVI rats were administered orally 0-6 mg/kg bw
    deltamethrin in arachis oil. Similarly, groups of C57 BL/6 mice
    received orally 0-8 mg/kg bw of deltamethrin in arachis oil. Results
    were not yet available to the Meeting.

              

    1/  See Annex 2 for WHO and FAO documentation.

    Special Studies on Eye Irritation

         Male albino rats (9) weighing between 2 and 3 kg were
    administered 0.1 ml of formulated deltamethrin (25 g/l mixofluid) into
    the conjunctival sac. Six of the treated eyes remained unwashed, while
    the remaining three were rinsed with lukewarm water 20-30 seconds
    after instillation. There was only transient clouding of the cornea in
    two animals one hour after dosing (1 washed, 1 unwashed), which
    cleared by day 2. Also noted was a low grade conjunctival irritation
    among all animals initially, which disappeared following day 2 of
    observations (Glomot  et al 1981d).

         The 2.5% WP deltamethrin formulation diluted 1/10 in distilled
    water (0.1 ml per rabbit) elicited a similar pattern of initial
    transient corneal clouding in three of nine rabbits examined, which
    cleared by day 4. The undiluted formulation, 100 mg, administered into
    the conjunctival sac of rabbits produced increased involvement of
    conjunctiva, iris and cornea in all animals, generally moderate in
    severity, with low grade corneal opacity persisting in two rabbits
    through day 7 (1 washed, 1 unwashed) (Glomot  et al 1981e).

    Special Study on Teratogenicity

    Mouse

         Groups of mated Swiss CD1, SPF mice (25/group) were orally
    gavaged with deltamethrin dissolved in sesame oil at dose levels of 0,
    0.1, 1 and 10 mg/kg bw/day administered during gestation days 6 to 17.
    This was a complementary teratology study to the Glomot and Vannier
    1977 evaluation and was experimentally designed to assess the effects
    on foetal and post-natal development, including embryotoxicity. One
    group of mated mice was sacrificed on day 18 of gestation and examined
    for gravid uterine weight, number of implantation sites, viable
    foetuses, dead foetuses and resorptions. Visceral and skeletal
    examinations were performed on the foetuses. Some females were allowed
    to produce litter, and full examinations of pups and dams were
    conducted on day 1 post-partum. Similarly, a third group of females
    was allowed to produce a litter and dams and pups were sacrificed on
    day 21 post-partum. Pup weights were determined on days 1, 4, 10 and
    21 post-partum.

         Results demonstrate that the conception and pregnancy rates were
    unaffected by treatment, except that maternal body weight gain was
    decreased in the 10 mg/kg bw group. Skeletal variants, consisting of
    delayed ossification of the sternebrae and phalanges in the 1 and
    10 mg/kg bw/day group pups at gestation day 18, were not present at
    day 1 or 21 post-partum. Extranumery ribs and reduced ossification of
    skull bones were not observed in this complementary study. Litter
    size, pup weight, viability and lactation index were all normal

    through day 21 post-partum. Deltamethrin administered during the
    period of major organogenesis in the mouse causes a moderate and
    transient retardation of development of the foetus at 1 mg/kg bw/day
    and higher doses, but these effects were not observed at day 1 or 21
    post-partum. There were no teratogenic effects related to treatment
    (Glomot and Vannier 1982).

    Special Studies on Skin Sensitization

         Male albino rabbits (6) weighing 2.5 to 2.9 kg were administered
    0.5 ml of formulated deltamethrin (25 g/l mixofluid) to both shaved
    intact and abraded skin. The Primary Irritation Index after 24 h
    exposure to occluded sites was 1.2, slightly irritating (Glomot
     et al 1981b).

         An evaluation similar to the one described above was determined
    for a 2.5% WP deltamethrin formulation. Rabbits had a Primary
    Irritation Index of 2.41, moderately irritating. Moderate erythema
    continued for 72 hours, while the oedema generally diminished, with
    the exception of scarified skin sites (Glomot  et al 1981c).

    Acute Toxicity

    Mouse

         Mice presented far fewer symptoms than rats after oral dosing
    at comparable levels, with diarrhoea being the only reportable
    observation (Glomot  et al 1980a).

    Rat

         The acute oral toxicity of low concentrations of deltamethrin to
    rats was without noticeable mortality but included symptoms observed
    at higher concentrations, including excessive grooming, diarrhoea,
    drowsiness, piloerection, ptosis, difficulty in walking, general motor
    incoordination and hypotonia (Glomot 1979; Glomot  et al 1979,
    1981a).

         Rats were exposed (whole-body exposure) for 4 hours to an aerosol
    concentration of deltamethrin equal to 2.8 g/m3, the highest
    attainable airborne concentration of a 2-5% formulation. Approximately
    80% of the total aerosol had a mean aerodynamic diameter less than
    5.5 Ám. Dyspnoea and gasping were observed in exposed rats. Relative
    lung weights and macroscopic pathology were normal. There were no
    mortalities (Clark  et al 1980).

    Dog

         Dogs orally dosed with a 2.5% formulation of deltamethrin
    displayed no clinical symptoms related to treatment (Glomot
     et al 1980b).

    Table 1  Acute Toxicity of Deltamethrin in Animals
                                                                        

                                    LD50
    Species   Route          Sex    (mg/kg bw)        Reference
                                                                        

    Rat       Oral1/         M/F    >5 000            Glomot et al
    1981a

    Rat       Oral2/         M      22 700            Glomot et al 1979
                                    (19 100-23 800)

    Rat       Oral2/         F      22 000            "
                                    (18 800-22 700)

    Rat       Oral3/         M/F    >15 000           Glomot 1979

    Rat       Inhalation3/   M/F    >2.8 g/m3         Clark et al 1980

    Mouse     Oral3/         M/F    >15 000           Glomot et al
                                                      1980a

    Dog       Oral3/         M/F    >10 000           Glomot et al
                                                      1980b
                                                                        

    1/  in an aqueous mixture of sodium carboxymethyl cellulose (0.25%)
        and polysorbate 80 (0.20%);

    2/  obtained for a 25 g/l flowable formulation;

    3/  obtained for a 2.5% wettable powder formulation.

    Observations in Humans

         Persons exposed to deltamethrin for 7-8 years of its production,
    syntheses and reformulation were subjected to medical observations,
    including both clinical and haematological examinations. Evaluations
    were conducted at several plants. There were no measurable effects
    other than transient cutaneous and mucous membrane irritation which
    was without sequelae. Adequate precautionary measures, such as gloves
    and face masks, provide protection from exposure (Foulhouz 1981).

         A medical survey of agricultural workers involved in the use and
    application of EC and WP formulations of deltamethrin in Yugoslavia
    revealed no untoward symptoms of exposure other than itching and
    burning of the face, as well as nasal hypersecretion. Medical
    examinations included chest x-ray, ECG, liver function tests,

    neurological exam (eye tonometry, Goldman perimetry, dark adaptation
    ability), kidney function tests, and whole blood and plasma
    cholinesterase activity. No adverse effects were noted. Proper use of
    masks and gloves, as well as good personal hygiene (e.g. washing),
    were emphasized (Plestina 1981).

         Four operators were evaluated during normal field applications
    of deltamethrin lasting one day. Three of the operators wore no
    protection on their heads or hands, while one wore hood, gloves and
    respirator. Motor and sensory nerve conduction velocities were
    determined as well as haematological and biochemical tests and
    urinalysis. No changes were observed in blood parameters measured and
    no residues were found in the urine samples. Furthermore, no decrease
    in nerve conduction velocity occurred. Residues were primarily
    confined to gloves and legs. None of the operators experienced
    symptoms of facial sensation (Hewson and Burgess 1981).

    COMMENTS

         The additional information reviewed clarified previous concerns.
    Embryotoxic effects observed are transient in nature, demonstrated
    only in the foetuses, and without sequelae in newborn animals up
    through 21 days post-partum.

         Data accumulated on workers exposed to deltamethrin (e.g. plant
    workers, field operators and supported by data in laboratory animals
    demonstrate that deltamethrin is irritating to skin and mucous
    membranes. This potential can be reduced by proper precautionary
    measures such as gloves, face shield and other appropriate clothing.
    Information would indicate that some of this irritation may be
    partially caused or enhanced by the solvent (i.e. xylene) in the
    EC formulation.

         Evaluation of the histopathology in the 2-year rat feeding study
    by independent pathologists confirmed that there were no dose-related
    effects. The axonal degenerations at 20 ppm were not significantly
    different from high dose or control animals. Historical data from the
    laboratory performing the study re-affirmed that the reported
    observation of testicular cell adenoma at 50 ppm were age related and
    within the limits of 1 000 control animals of the same strain.

         The Meeting noted with interest the neurological effects observed
    in both acute and short-term studies, which were not observed in
    longer-term studies. The high doses of the long-term studies in rat
    and dog were equivalent to the lower doses utilized in the short-term
    studies, which provides a possible reason for the absence of such
    response.

         The Meeting was made aware of ongoing long-term carcinogenicity
    studies in the rat and mouse from which results are not yet available
    and hoped that these would be made available to the JMPR when they are
    completed. Additional data and information made available to the
    Meeting provided sufficient data to recommend an ADI.

    TOXICOLOGICAL EVALUATION

    Level Causing no Toxicological Effect

    Rat:      50 ppm in the diet, equivalent to 2.1 mg/kg bw.

    Mouse:    100 ppm in the diet, equivalent to 12 mg/kg bw.

    Dog:      40 ppm in the diet, equivalent to 1 mg/kg bw.

    Estimate of Temporary Acceptable Daily Intake for Man

    0 - 0.01 mg/kg bw.

    FURTHER WORK OR INFORMATION

    Desirable

    1.   Studies on the significance of neurological effects observed in
         several animal species.

    2.   Results from the IARC carcinogenicity studies in mouse and rat.

    3.   Further information on exposure of humans to deltamethrin.

    REFERENCES

    Clark, G.C., Jackson, G.C. and Alexander, D.J. Acute inhalation
    1980     toxicity in rats, 4-hour exposure (Decis PM 2.5 percent).
             Report (ref.: RSL 437/80568) from Huntingdon Research
             Centre, U.K., submitted to the World Health Organization by
             Roussel Uclaf. (Unpublished)

    Foulhouz, P. Medical observations of personnel working on synthesis
    1981     or formulation of deltamethrin. Report (ref.: RU-81.18.06/A)
             from Roussel Uclaf submitted to the World Health
             Organization by Roussel Uclaf. (Unpublished)

    Glomot, R. Acute toxicity study by oral route in the rat, Report
             (ref.: RU-79 803-54/A2) 1979 from Roussel Uclaf, submitted
             to the World Health Organization by Roussel Uclaf.
             (Unpublished)

    Glomot, R., Audegond, L. and Collas, E. Acute oral toxicity study
    1979     in the rat (Decis 25 G/L Mixofluid). Report (ref.: RU
             79824/A) from Roussel Uclaf submitted to the World Health
             Organization by Roussel Uclaf. (Unpublished)

    1980a    Single administration by oral route in the mouse (Decis
             Wettable Powder, 2.5%). Report (ref:RU-80.817/A) from
             Roussel Uclaf submitted to the World Health Organization by
             Roussel Uclaf. (Unpublished)

    1980b    Single administration study by oral route in the dog (Decis
             Wettable powder, 2.5%). Report (ref.: RU 80.194/A) from
             Roussel Uclaf submitted to the World Health Organization by
             Roussel Uclaf. (Unpublished)

    1981a    Single administration study by oral route in the rat. Report
             (ref.: RU-81239/A) from Roussel Uclaf, submitted to the
             World Health Organization by Roussel Uclaf. (Unpublished)

    1981b    Primary dermal irritation study in the rabbit. Deltamethrin
             25 G/L Mixofluid). Report (ref.: RU-79193/A) from Roussel
             Uclaf, submitted to the World Health Organization by Roussel
             Uclaf. (Unpublished)

    1981c    Primary dermal irritation study in the rabbit (Deltamethrin
             wettable powder, 2.5%). Report (ref.: RU80200/A) from
             Roussel Uclaf, submitted to the World Health Organization by
             Roussel Uclaf. (Unpublished)

    1981d    Primary eye irritation study in the rabbit (Deltamethrin in
             25 G/L Mixofluid). Report (ref.: RU79192/A) from Roussel
             Uclaf, submitted to the World Health Organization by Roussel
             Uclaf. (Unpublished)

    1981e    Primary eye irritation study in the rabbit (Decis Wettable
             Powder, 2.5%). Report (ref. RU79192/A) from Roussel Uclaf,
             submitted to the World Health Organization by Roussel Uclaf.
             (Unpublished)

    Glomot, R. and Vannier, B. Complementary teratological study in the
    1982     mouse. Report (ref.: RU-82.506-12/A), from Roussel Uclaf,
             submitted to the World Health Organization by Roussel Uclaf.
             (Unpublished)

    Hewson, R.T. and Burgess, J.E. An operator study with deltamethrin
    1981     including measurements of nerve conduction times. Report
             (ref.: GB-NT-11.81/A) from Roussel Uclaf, submitted to the
             World Health Organization by Roussel Uclaf. (Unpublished)

    Plestina, R. An evaluation of the use of deltamethrin in public
    1981     health. Report (ref.: ZAG. KOT. 81/A) from Roussel Uclaf,
             submitted to the World Health Organization by Roussel Uclaf.
             (Unpublished)

    DELTAMETHRIN

    CHEMICAL STRUCTURE 2

    Explanation

         Deltamethrin was reviewed by the Joint Meeting in 1980 and 1981
    (FAO/ WHO 1981, 1982)1. In the absence of an ADI, guideline levels
    were proposed on a wide variety of agricultural commodities. The
    results of supervised trials on residues in meat, milk and eggs
    arising from uses for ectoparasite control, in feeding studies and in
    stable treatments were required by 1982. Also requested was more
    information on the level and fate on various cereal grains treated
    under different storage conditions, the effects of processing and
    cooking, more residue data on kiwi fruit, currants and leafy
    vegetables, the level and fate of residues in foods of animal origin
    following feeding and more information on levels on cereal grains.

         Information was received on residue levels on greenhouse
    cucumbers and tomatoes and on stored wheat, wheat bran and wheat
    flour. Data on residue levels in meat, milk and eggs arising from
    ectoparasite control and stable treatments is under development but
    not yet available.

    RESIDUES IN FOOD AND THEIR EVALUATION

    USE PATTERN

    Preharvest

         New information was received from the Netherlands (Netherlands
    1982) on preharvest treatments in use since 1981 on a wide variety of
    crops, as shown in Table 1.

              

    1/  See Annex 2 for FAO and WHO documentation.

        Table 1.  Deltamethrin Use Pattern in the Netherlands
                                                                                                         

    Crop                            Application rate (a.i.)                               Preharvest
                                    g/100 l         g/ha          Formulation             Interval (days)
                                                                                                         

    Apple, pear 2                   0.5             75            EC 25 g/l               7
    Strawberries 1                  0.5                           "                       -
    Blackberries, 1                 0.5                           "                       7
     raspberries
    Currants(black, 2               0.5                           "                       7
     red,white),grapes,
     gooseberries
    Cherry, plums 1                 0.5                           "                       7
    Courgettes, 1                   1.25                          "                       3
    cucumbers,eggplant,
    melons, sweet peppers
    tomatoes
    Lettuce, 1                      1.25            25            EC 25 g/l               14
     endive
    Sweet fennel 1                                  7.5           "                       7
    Black radish, 1                                 7.5           "                       7
     radish, turnip,
     rutabaga
    Broccoli, 1                                     7.5           "                       7
     cauliflower,
     Chinese cabbage,
     cabbages, savoy,
     curly kale,
     kohlrabi
                                                                                                         

    Table 1.  (con't)
                                                                                                         

    Crop                            Application rate (a.i.)                               Preharvest
                                    g/100 l         g/ha          Formulation             Interval (days)
                                                                                                         

    Leek, 1                                         7.5           "                       7
     onions
    Peas, 1                                         7.5           "                       7
     french beans
    Potatoes 1                                      7.5           "                       7
    Sugar and fodder beet 1                         7.5           "                       -
    Poppy, 1                                        7.5           "                       7
     flax
    Radish leaves, 1                                7.5           "                       7
     cabbage greens,
     turnip greens
    Mushrooms 1                     0.75-1.5                      spray on beds,walk,     2
                                                    0.075         ceiling, swing or       2
                                                                  pulsfog treatment
                                                                                                         

    1  Small-scale use;    2  moderate-scale use.
    
    RESIDUES RESULTING FROM SUPERVISED TRIALS

         Some additional data were available from Finland (Finland 1982)
    for residues on greenhouse cucumbers and tomatoes. Cucumbers were
    sprayed at 2.1 mg a.i./plant; no residues (<0.05 mg/kg) were detected
    in samples harvested at 1, 5 and 8 days post-treatment. Tomatoes were
    sprayed at 1 mg a.i./plant; no residues (<0.05 mg/kg) were found in
    samples collected at 1, 5 and 8 days post-treatment.

    FATE OF RESIDUES

    In Storage and Processing

         Additional data were received on the behaviour of deltamethrin on
    stored wheat arising from experiments conducted in Australia and
    Greece (Table 2). Residues on wheat grain were roughly proportional to
    half the treatment rate and showed no measurable losses during storage
    for over a year. Residues in bran prepared from the stored wheat
    treated at at 1 mg/kg ranged from 0.3 - 1.5 mg/kg, while corresponding
    residues in flour (white) ranged from 0.01 - 0.07 mg/kg (UniversitÚ de
    Montpellier 1981a,b).

    NATIONAL MAXIMUM RESIDUE LIMITS

         An updated list of national MRLs was provided to the Meeting by
    the Netherlands (Netherlands 1982).

    Commodity                              MRL (mg/kg)

    Strawberries                            0.05
    Other fruits                            0.1
    Leafy vegetables                        0.2
    Other vegetables                        0.05
    Potatoes                                0.05
    Meat and milk                           0.05
    Other food commodities                  0.05

    APPRAISAL

         The results of supervised trials in Finland on greenhouse
    cucumbers and tomatoes sprayed with deltamethrin at 2.1 and
    1.0 mg a.i./plant respectively showed no measurable residues;
    <0.05 mg/kg were found even at 1 day post-treatment, and therefore
    the guideline level of 0.05 mg/kg would not be exceeded.

         Additional data on the behaviour of deltamethrin residues on
    stored wheat treated at 0.25, 0.50 and 1.0 mg/kg confirmed that no
    measurable degradation occurs on the grain over storage periods of
    more than a year. Measured values ranged from 0.1 - 0.16, 0.25 - 0.27

        Table 2.  Residues of Deltamethrin on Stored Wheat 1
                                                                                                                                           

    Location    Rates      Part                          Interval (days) following last application
    (Year)      Applied    of                                                                                                              
                (mg/kg)    Sample       7                   90                                180                     270
                                                                                                                                           

    Greece      0.25       Grain        0.13                0.10                              0.13                    0.16
    1980        0.50       Grain        0.25                0.25                              0.27                    0.27
                           (Days)       40/48     77        81         118/137      186       223/242      281        318/337     383/420
                                                                                                                                  >1 year
    Australia   1 A        Grain                  0.3                  0.5                    0.25                    0.4
    1980-1982              Bran                   1.2                  1.3                    0.5                     0.3
                           Flour                  0.06                 0.06                   0.06                    0.01
                           (white)
                1 B        Grain        0.2                            0.5                    0.4                     0.35        0.2
                           Bran         0.85                           1.1                    1.4                     0.75        1.2
                           Flour        0.06                           0.08                   0.07                    0.01        0.06
                           (white)
                1 C        Grain        0.25                0.35                    0.3                    0.35
                           Bran         1.1                 0.8                     1.4                    1.5
                           Flour        0.05                0.07                    0.07                   0.01
                           (white)
                1 D        Grain        0.15                0.4                     0.3                    0.45
                           Bran         1.3                 1.2                     1                      1
                           Flour        0.06                0.06                    0.07                   0.02
                           (white)
                1 E        Grain        0.2                 0.3                     0.4                    0.4                    0.25
                           Bran         1.4                 0.9                     1.2                    1.2                    1.3
                           Flour        0.07                0.07                    0.07                   0.06                   0.06
                           (white)
                                                                                                                                           

    1  All data based on one treatment.
        and 0.15 - 0.5 mg/kg respectively. Bran obtained from the stored wheat
    treated at the 1 mg/kg level contained most of the residue (range
    0.3 - 1.5 mg/kg) while the corresponding white flour contained the
    least (range 0.01 - 0.07 mg/kg). Taking existing or possible use
    patterns into consideration, these data support the previously
    proposed guideline levels for cereal grains, wheat bran and wheat
    flour.

         Studies are still under way for determining residues occurring in
    meat, milk and eggs arising from ectoparasite and stable treatments
    and will be made available by 1984.

    RECOMMENDATIONS

         The previous guideline levels are converted to temporary maximum
    residue limits on the basis of the newly recommended temporary ADI for
    deltamethrin.

    FURTHER WORK OR INFORMATION

    Desirable (as available)

    1.   Results of planned or ongoing studies on residue behaviour on
         stored crop commodities for the purpose of recommending new or
         revising previous MRLs on such commodities (estimated date -
         1983),

    2.   Results of planned or ongoing supervised animal studies on
         residues in meat, milk and eggs resulting from ectoparasite and
         stable treatments for the purpose of recommending new MRLs on
         those commodities (estimated date - 1984).

    REFERENCES

    Finland   Table on deltamethrin residues (official testing),
    1982      (Personal communication)

    Netherlands Tables of preharvest treatments and national MRLs.
    1982      (Personal communication)

    UniversitÚ de Montpellier. Residues determination in plants. Wheat
    1981a     (stored). Research Report FP-81.27.04/A.

    UniversitÚ de Montpellier, Residues determination in plants. Wheat
    1981b     (stored).  Research Report FP-82.18.03/A.


    See Also:
       Toxicological Abbreviations
       Deltamethrin (EHC 97, 1990)
       Deltamethrin (HSG 30, 1989)
       Deltamethrin (ICSC)
       DELTAMETHRIN (JECFA Evaluation)
       Deltamethrin (Pesticide residues in food: 1980 evaluations)
       Deltamethrin (Pesticide residues in food: 1981 evaluations)
       Deltamethrin (Pesticide residues in food: 1984 evaluations)
       Deltamethrin (JMPR Evaluations 2000 Part II Toxicological)
       Deltamethrin (UKPID)
       Deltamethrin (IARC Summary & Evaluation, Volume 53, 1991)