WHO Pesticide Residues Series, No. 1



    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



    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



    Chemical names


    ethyl 2,4,5-trichlorophenyl ethylphosphonothionate


    (R) Agritox, (R) Phytosol, (R) Agrisil, BAY 37 289, S 4400

    Structural formula


    Other information on identity and properties

    The active ingredient is a light brown liquid and has a boiling point
    of 108°C at 0.01 mm Hg. It has a vapour pressure of 1.5 × 10-5 mm Hg
    at 20°C and a volatility of 0.27 mg/m3 at 20°C. Its solubility in
    water at 20°C is approximately 50 ppm, in kerosenes poor, but in
    alcohol, acetone, chlorinated hydrocarbons and aromatic solvents good.
    The stability of the active ingredient to hydrolysis is high in the
    acid range, but in the alkaline range it decomposes quite readily
    (Bayer, 1969).

    Composition of the technical trichloronat is reported to be (Bayer,

       active ingredient                                         93.0 - 95.0%
       free 2,4,5-trichlorophenol                                0.05 - 0.5%
       O-ethyl-O-(2,4-dichlorophenyl)-ethylmonothiophosphonate   0.4 - 1.0%
       O,O-diethyl ethylthiophosphonate                          0.1 - 0.5%
       sum of two unknown, low boiling compounds                 1.0 - 1.5%
       sum of three to four unknown, high
       boiling compounds                                         3.0 - 5.0%
       H2O                                                       0.01 - 0.9%

    Furthermore an analytical method for the determination of
    2,3,7,8-tetrachlorodibenzo-p-dioxin in the technical material has
    been worked out. Samples analysed have contained less than 0.1 ppm of
    "dioxin" which is the limit of detection. It is guaranteed by the
    manufacturer that the "dioxin" content of the trichloronat
    preparations is less than 0.1 ppm in terms of the active ingredient
    (Bayer, 1971).


    Biochemical aspects

    Absorption and distribution

    No information available.


    No information available.


    No information available.

    Effects on enzymes and other biochemical parameters

    Three groups of three male rats orally dosed with 7.5, 3.8, or 1.9
    mg/kg showed whole blood cholinesterase depression of 30, 15, and 0%
    after three hours, 35, 25 and 15% after 24 hours, and 15, 0-10, and 0%
    after 72 hours respectively (Kimmerle, G., 1962).

    Trichloronat is ineffective as a cholinesterase inhibitor in vitro,
    but is a strong inhibitor in vivo after i.p. administration of
    7 mg/kg to rats. Maximum inhibition of brain, serum, and submaxillary
    gland cholinesterase occurred in 1-6 hours. Reversal of inhibition was
    slow, only returning to 60-75% of normal after 7 days (Root et al.,

    Inhalation exposure of groups of 10 hens, for four hours five times
    weekly for four weeks resulted in 60.4, and 76.7% whole blood
    cholinesterase depression at air concentrations of 0.033, and 0.048
    mg/l respectively (Kimmerle, G., 1968).


    Special studies


    Four groups each comprising 10 male and 20 female rats were fed 0, 3,
    10 and 30 ppm 95% pure trichloronat in the diet through three
    generations. The second litter from each generation, F1b, and F2b,
    was used as parents to establish the next generation.

    No adverse effects were noted among the parental animals except for
    depression of growth rate at 30 ppm. Reproductive performance was
    normal at all dose levels, but pup growth was depressed at 30 ppm,
    although litter size and birth weight were normal. In the third
    generation, the survival of the pups was adversely affected by 30 ppm
    trichloronat. No terata were observed (Löser, 1971).


    Exposure of groups of five hens to 0.055, 0.126, 0.248, or 0.585 mg/l
    air for four hours resulted in 100% mortality at the two upper dose
    levels. Examination of survivors 42 hours after exposure did not
    reveal neurotoxic effects. Further groups pre-treated i.m. with 100 mg
    PAM/kg and 50 mg atropine sulphate/kg exposed to 0.185, 0.4, 0.583 or
    0.784 mg/l air resulted in three deaths out of five at the upper two
    dose levels. All survivors exposed to 0.4 mg/l air and above showed
    neurotoxic effects. Four-hour exposures repeated on five consecutive
    days at 0.053, 0.126, 0.143 or 0.162 mg/l air did not result in
    neurotoxic effects, although 1/5 and 5/5 hens died at the two top dose
    levels. Birds similarly exposed after PAM and atropine treatment, to
    levels of 0.222, or 0.376 mg/l air, all showed neurotoxic effects.
    Neurotoxic effects were not observed following four-hour exposures
    five times weekly for four weeks to air concentrations of 0.033 or
    0.048 mg/l air (Kimmerle, 1968).

    Neurotoxic effects were not observed in 1-2 year-old hens unprotected
    against the cholinergic effects of trichloronat when single doses up
    to those which proved lethal were given. However, when the hens were
    protected with i.p. injections of atropine sulphate and 2-PAM, higher
    doses of trichloronat could be given and 100 mg/kg i.p. or 150 mg/kg
    orally produced neurotoxic effects. This effect of trichloronat was
    not detected in a sub-acute experiment in which 0, 250, 500, 1000 and
    2000 ppm trichloronat in the diet was fed to groups of eight hens for
    30 days. Two hens per group were killed after the treatment period,
    the rest were killed 30 days later; neurotoxic effects were not
    observed (Kimmerle, 1965).


    Trichloronat administered simultaneously with malathion resulted in a
    two-fold potentiation of the malathion toxicity (Root et al., 1969).

    Toxicity of contaminants

    2,4,5-Trichlorophenol is known to occur as a contaminant of
    trichloronat at a level of 1-2%.

    Groups of young male and female rats were fed dietary levels of 100,
    300, 1000, 3000 and 10 000 ppm of 2,4,5-trichlorophenol for 98 days.
    Records were kept concerning appearance, behaviour, mortality, food
    consumption, body and organ weights and terminal haematological tests
    (urea nitrogen, leucocyte counts, haematocrits and haemoglobin
    values). No evidence of adverse effects was noted at the 1000 ppm
    levels or less. At 3000 and 10 000 ppm the rats showed diuresis and
    slight pathological changes of the kidney and liver, and at the 10 000
    ppm level there was a slight decrease in growth (McCollister et al.,

    2,3,7,8-Tetrachlorodibenzo-p-dioxin ("dioxin") is also a possible
    contaminant of trichloronat. The sole manufacturer of trichloronat
    states that the level of "dioxin" is below 0.1 ppm in technical
    trichloronat. (See "Identity").

    Acute toxicity


    Species        Route          LD50           Reference

    Mouse          i.p.           33-35          DuBois and Kinoshita, 1963

    Rat (M)        oral           16-55          DuBois and Kinoshita, 1963;
                                                 Gaines, 1969; Kimmerle,
                                                 1968; Kimmerle, 1967

    Rat (F)        oral           16-37.5        DuBois and Kinoshita, 1963;
                                                 Gaines, 1969; Kimmerle,

    Rat (M)        i.p.           10-14          DuBois and Kinoshita, 1963;
                                                 Kimmerle, 1962

    Rat (F)        i.p.           11-37.5        Dubois et al., 1966;
                                                 Kimmerle, 1962


    Species        Route          LD50           Reference

    Rat            dermal         64-250         DuBois and Kinoshita, 1963;
                                                 Gaines, 1969; Kimmerle,

    Guinea-pig     oral           40-100         DuBois and Kinoshita, 1963;
                                                 Kimmerle, 1962

    Guinea-pig     i.p.           26             DuBois and Kinoshita, 1963

    Rabbit         oral           25-50          Kimmerle, 1962

    Cat            oral           10-25          Kimmerle, 1962; Kimmerle,

    Chicken        oral           45             DuBois, 1963

    Groups of five female rats were injected i.p., daily for 60 days, at
    dose levels of 0, 2, 4, 6 and 8 mg/kg/day. Mortality resulted in 2 out
    of 5, 4 out of 5, and 5 out of 5 at 4, 6 and 8 mg/kg respectively.
    Body weight was reduced at all dose levels, although some recovery
    occurred at 2 and 4 mg/kg after 20 days on the test. Survivors
    autopsied at 60 days showed marked depression of serum, submaxillary
    gland, and brain cholinesterase (DuBois et al., 1966).

    Rabbit. A pair of rabbits dosed orally, five times weekly for two
    weeks with 5 mg/kg/dose did not lose body weight or display symptoms
    of poisoning (Kimmerle, 1962).

    Liver function tests (BSP, SG.OT, SG-PT) were unaffected by 20 mg/kg
    (one rabbit) or 10 mg/kg (two rabbits) administered as a single oral
    dose (Kimmerle, 1962).

    Dog. Groups of beagle dogs were fed 0, 2, 5, 10 (two males and two
    females/group or 25 (one male and one female) ppm in dry diet for 12
    weeks. At termination of the study, erythrocyte cholinesterase was
    depressed at 25 ppm (40%) in the females. Plasma cholinesterase was
    depressed in both sexes at 10 ppm (39% in males and 27% in females)
    but in females only at 25 ppm (41%). Brain cholinesterase was
    comparable to control values for all groups. Liver cholinesterase was
    depressed in males at 5 ppm and above (depression exceeding 20%), and
    in females at 10 ppm and above. Thyroid weight and weight ratio were
    decreased at 25 ppm (Root at al., 1968b). Histopathological changes
    including lymphocytic proliferation of the intestinal wall were not
    dose-related (Hibbs and Nelson, 1968).

    Groups of two male and two female beagle dogs were fed 0 or 5 ppm in
    the dry diet for two years. A further group was fed 25 ppm for 18
    months. The 25 ppm dose level was then increased to 50 ppm for the
    next seven weeks, to 100 ppm for the subsequent 14 weeks and finally
    to 200 ppm until the termination of the study. A final group was fed 2
    ppm for two years, and then 1 ppm for a further 13 weeks, and then
    control diet for the final eight weeks prior to autopsy. Body symptoms
    in all cases reported were typical of cholinesterase depression.

    Short-term studies

    Rat. Groups of 10 male rats were incubated five times weekly for
    eight weeks with 0.75, 1.5, 3, 6, or 12 mg/kg/dose followed by a four
    week observation period. Symptoms of cholinesterase depression were
    seen at 12 mg/kg after the first dose only (Kimmerle, 1968).

    Groups of 20 male and 20 female rats were fed 0, 1, 3, 10 or 30 ppm of
    95% pure trichloronat in the diet for three months. Final body weight
    was comparable, but males fed 10 and 30 ppm showed a slight dose
    related lag in weight gain during the second month. Signs of
    cholinesterase depression were seen during the morning from the second
    week in rats fed 30 ppm and in some rats fed 10 ppm. Plasma and
    erythrocyte cholinesterase levels were depressed at 10 and 30 ppm,
    erythrocyte cholinesterase being depressed slightly more than plasma
    cholinesterase. Depression at 3 ppm in plasma and erythrocytes was
    less than 20% (Löser, 1968).

    Groups of 15 male and 15 female rats were fed 2.25, 4.5, 9 or 18 ppm
    of technical trichloronat in the diet for four months. The control
    group comprised 30 male and 30 female rats. Cholinesterase depression
    in whole blood was apparent in females at 4.5 and 9 ppm at four weeks.
    At eight weeks, male rats showed depression at 9 and 18 ppm, and
    females at 18 ppm only. At 12 and 16 weeks, cholinesterase depression
    was apparent in both sexes at 18 ppm only (Löser, 1966).
    Histopathological examination revealed low-grade fatty changes in
    isolated epithelial cells of the liver of five male rats fed 18 ppm
    (Hobik, 1967).

    Five groups of 10 male and 10 female rats were fed 0, 2, 5, 10 or 25
    ppm in the diet for 16 weeks. Terminal cholinesterase determinations
    indicated depression occurred in erythrocytes at 10 and 25 ppm, in
    brain and submaxillary glands at 25 ppm and in plasma of female rats
    at 25 ppm. Depression was less than 20% in all other groups, and less
    than 10% except for plasma in females at 10 ppm and erythrocytes in
    males at 5 ppm (Root at al., 1968a). The presence of dilated kidney
    tubules with eosinophilic casts was observed in all groups, but the
    incidence was considerably greater in the test groups (Grey at al.,
    1968). Weight and food consumption were reduced at 200 ppm. Signs of
    cholinesterase depression became apparent within three weeks of
    feeding 200 ppm. One male dog died after nine weeks exposure at this
    level. Erythrocyte cholinesterase was comparable to controls until the

    dose was increased to 75 ppm, at which dose depression occurred. The
    depression increased when the dose was increased to 200 ppm. Plasma
    cholinesterase was depressed at 2 ppm and above, depression being
    about 20% at 2 ppm. When the dose was reduced to 1 ppm, recovery to
    99% of normal activity occurred. At autopsy, liver cholinesterase was
    inhibited 45% at 5 ppm. No reduction was observed in the group reduced
    from 2 to 1 to 0 ppm. Brain cholinesterase was reduced 10% at 5 ppm,
    and 72% at the top dose level. No compound related histological
    changes were apparent (Root et al., 1970).

    Long-term studies

    Rat. Four groups of 30 male and 30 female rats were fed 1, 3, 10, or
    30 ppm of 95% pure trichloronat in the diet for two years. The control
    group comprised 60 males and 60 females. Body weight of males at 30
    ppm was reduced, female body weight at 30 ppm was reduced between 9
    and 12 months. Food consumption at 30 ppm was marginally reduced.
    Average absolute weight of male heart, lung, liver, kidney, and spleen
    were depressed, but organ/body weight ratio was unaffected. Signs of
    cholinesterase depression were apparent in the morning during the
    first three months in the 30 ppm group. Plasma and erythrocyte
    cholinesterase were depressed at 10 and 30 ppm, although at 10 ppm the
    depression became marginal as the study progressed. Terminal brain
    cholinesterase was depressed at 10 and 30 ppm in both sexes, and
    marginally depressed (17%) in males at 3 ppm. Histopathological data
    have not been submitted (Löser, 1970).

    Observations in man

    No information is available.


    Trichloronat is a persistent organophosphorus insecticide used for
    soil treatment. No information is available on the absorption,
    distribution, excretion or general metabolism in animals.

    Short-term studies in the rat and dog, one long-term (two-year) study
    in the rat and a three-generation reproduction study in rats are
    available. In the short-term study some histopathological changes were
    observed, the nature of which could not be assessed. In the long-term
    studies insufficient information was available both on gross and
    histopathology of the organs.

    For this reason and because there is no information on the metabolism
    of this persistent insecticide the Meeting decided that no acceptable
    daily intake for man could be established at this time.


    Use pattern

    Trichloronat is an insecticidal compound with a contract and stomach
    action and with a residual activity of relatively long duration for a
    phosphorus insecticide. It is especially used for the control of
    soil-inhabiting developmental stages of different insect species and
    vegetable fly larvae. The formulations currently on the market are as
    follows (Bayer, 1969; 1971):

                         2.5%  granular (Gr.)
                         7.5%  granular (Gr.)
                        20.0%  seed dressing powder (S.D.P.)
                        50.0%  emulsifiable concentrate (E.C.)

    Practically all trichloronat manufactured is applied to vegetable

    Pre-harvest treatments

    The recommended usages of trichloronat (Bayer, 1969) with regard to
    crops, pests, formulations, and rates are given below:


    Onions, leeks       Hylemyia antiqua (Onion fly)

    50% E.C.            10 litres per hectare, spray presowing and work
                        in just below the surface;
                        0.1% (250 cm3 per running metre), drench at
    7.5% Gr.            25 kg/hectare (or 7.5 g/10 metres), row treatment
                        at sowing;
    2.5% Gr.            80-100 kg/hectare (or 2.5 g per running metre),
                        row treatment at sowing;
    20% S.D.P.          75-100 g/kg seed, before treatment, moisten
                        seed using 50-75 cm3 of water; sow within 24
                        hours of treatment.

    Brassica crops      Hylemyia brassicae (Cabbage root fly)
                        Hylemyia floralis (Turnip fly)

    50% E.C.            0.04% (1 litre/m2), treatment of nursery seedbed
                        or 10 litres per hectare, spray presowing, and
                        work in just below surface, or
                        0.1% (250 cm3 per running metre, or 80-100 cm3/
                        Plant), drench at egg-laying;
    7.5% Gr.            4 g/m2, treatment of seedbed, or 25 kg/hectare,
                        row treatment at transplanting;


    Onions, leeks       Hylemyia antiqua (Onion fly)

    2.5% Gr.            1-2 kg/m3 for treatment of nursery bed soil, or
                        800 g/100 metres, row treatment at planting or
                        100 kg/hectare, row treatment at transplanting,
                        or 1-2 g/plant applied to stem base at
                        transplanting (also as mixture with sand), or
                        3-5 g/plant hole at transplanting.

    Carrots             Psila rosae (Carrot fly)

    50% E.C.            10 litres/hectare, spray presowing and work in
                        just below surface;
    2.5% Gr.            100 kg/hectare, row treatment at sowing;
    20% S.D.P.          100 g/kg seed.

    Cereals             Hylemyia coarctata (Wheat bulb fly)

    2.5% Gr.            80-100 kg/hectare, broadcast treatment;
    20% S.D.P.          250 g/100 kg seed.
                        If fungicides are additionally applied use only
                        non-mercurial products.

    Bananas             Cosmopolites sordidus (Banana weevil borer)

    2.5% Gr.            40-60 g/banana plant, apply in a radius of up
                        to 40 cm around stem.

    Grassland           Costelytra zealandica, Heteronychus arator,
                        Oncopera intricata, Wiseana

    2.5% Gr.            20-80 kg/hectare, broadcast treatment;
    50% E.C.            2 litres/hectare, broadcast treatment.

    Trichloronat is recommended for testing on some additional pests.

    Other uses

    The compound is also used for termite-proofing of polyethylene,
    plasticized PVC and rubber.

    Residues resulting from supervised trials

    The residue data from supervised trials are given in Table I. They are
    compiled from the documentation made available by Bayer (1971).



    Crop          Country     Formulation    Application            Pre-harvest    Residue
                              used1          rate2                  interval       (ppm)3

    Onions        Germany     50% E.C.       10 l/ha                100-133        n.d.-0.02
                  Belgium       "            8 l/ha                 35             n.d.
                  Germany       "            0.1% spray
                                             250 ml/row-m           58; 71         5.5; 1.6
                  Germany     2.5% Gr.       200 kg/ha              163            n.d.
                    "           "            1.5; 2.5 g/
                                             row-m                  100-133        n.d.-0.1
                  Finland     20% S.D.P.     100 g/kg seed          91-119         n.d.-0.3
                  Denmark       "            3; 5 g/kg
                                             transplant roots       82; 110        0.2; 1.2
    Leeks         Germany     50% E.C.       10 l/ha                121            n.d.
    Cabbages      Germany     50% E.C.       2% spray 2 ml/
                                             plant                  55             n.d.
                  Belgium       "            0.2% spray
                                             100 ml/plant           48             n.d.
                  Germany       "            0.1% spray
                                             250 ml/row-m           110            n.d.
                  USA         E.C.           1 x 0.13 g a.i./
                                             plant + 2 × 0.18 g/
                                             a.i./row-m             23-44          n.d.
                  Germany     2.5% Gr.       2 g/plant              31; 62         n.d.
    Cauliflower   Germany     50% E.C.       6; 8; 10 l/ha          50-69          n.d.-0.01
                    "           "            0.05% spray
                                             100 ml/plant           55             n.d.
                    "           "            0.1% spray
                                             80 ml/plant            42; 52         n.d.
                    "           "            2% spray 2 ml/
                                             plant                  69             n.d.
    Cauliflower   USA         E.C.           1 × 0.13 g a.i./       42-61          n.d.
                                             plant + 2 × 0.18 g
                  Germany     2.5% Gr.       2 g/plant              35-60          n.d.-0.1
                    "         20% S.D.P.     100 g/kg seed          76             n.d.
    Broccoli      USA         E.C.           1 × 0.13 g a.i./       26-41          n.d.
                                             plant + 2 × 0.18 g
    Brussels      USA         E.C.           1 × 0.13 g a.i./       40-58          n.d.
    sprouts                                  plant + 2 × 0.18 g

    TABLE I (Cont'd.)


    Crop          Country     Formulation    Application            Pre-harvest    Residue
                              used1          rate2                  interval       (ppm)3

    Kohlrabi      Germany     50% E.C.       6; 8; 10 kg/ha         30-50          0.01-0.08
                    "           "            0.05% spray
                                             100 ml/plant           19-45          0.01-0.1
                    "         2.5% Gr.       1 g/plant              19-45          0.04-0.4
    Carrots       Denmark     50% E.C.       4 l/ha                 76-174         0.05-0.2
                    "           "            8 l/ha                   "            0.04-0.2
                  Belgium       "              "                    44; 79         3.6;* 5.0*
                  Germany       "            10 l/ha                94; 97         0.2; 0.5
                    "           "              "                    68-148         0.06-0.4
                    "         2.5% Gr.       100 kg/ha              64-92          0.05-0.3
                  Norway        "              "                    62-139         0.3-0.6
                  France        "              "                    135-172        0.01-0.02
                  Belgium       "              "                    51; 81         n.d.
                  Italy         "              "                    193            0.2
                  Denmark       "            80 kg/ha               76             19.0*
                    "           "              "                    90             11.0*
                    "           "              "                    100-187        1.1-3.8*
                  Germany       "            150 kg/ha              46-166         n.d.-2.0*
                  Holland       "            2.5 g/row-m            111            0.6
                  Sweden        "            3.5 g/row-m            156            0.8
                    "           "            5.0 g/row-m              "            1.4
                    "           "            9.5 g/row-m              "            2.3
                  Denmark     20% S.D.P.     100 g/kg               76-174         0.03-0.3
                  Finland       "              "                    85-119         0.02-0.2
    Barley        Germany     2.5% Gr.       100 kg/ha              135            n.d.
    Corn            "         2.5% Gr.       80 kg/ha               169            n.d.
    kernels       USA         Gr.; E.C.      5.6 kg a.i./ha         34-114         n.d.
    cobs            "           "              "                      "            n.d.
    forage          "           "              "                      "            n.d.
    Oats          Germany     2.5% Gr.       100; 150 kg/ha         97; 135        n.d.
    Rye             "         20% S.D.P.     250 g/kg seed          294            n.d.
    Bananas       Ecuador     2.5% Gr.       45; 67.5 g/plant       3-180          n.d.
    Potatoes      Germany     2.5% Gr.       150 kg/ha              150            0.02
                  Belgium       "              "                    49; 62         0.3; n.d.
    sweet         USA         Gr.; E.C.      5.6 kg a.i./ha         116-164        n.d.
    Radish        Germany     50% E.C        5; 10 kg/ha            21; 36         0.01; 0.1
                    "         2.5% Gr.       100 kg/ha              21; 36; 41     0.03; 0.04;
                    "         20% S.D.P.     100 g/kg seed          58             0.5-0.7
                  Finland       "              "                    47             0.5
    Rutabaga      Finland     20% S.D.P.     100 g/kg seed          91; 135        n.d.; 0.05
                  Denmark       "              "                    73; 153        n.d.

    TABLE I (Cont'd.)


    Crop          Country     Formulation    Application            Pre-harvest    Residue
                              used1          rate2                  interval       (ppm)3

    roots         Germany     2.5% Gr.       150 kg/ha              160            n.d.
    tops            "           "              "                      "            n.d.
    roots         USA         10% Gr.        0.1-0.3 g a.i./
                                             row-m                  147-190        n.d.-0.1
    tops            "           "              "                      "            n.d.-0.02
    roots         Germany     2.5% Gr.       150 kg/ha              175            n.d.
    tops            "           "              "                    163            0.01

    1 E.C. = emulsifiable concentrate.
      Gr. = granular.
      S.D.P. = seed dressing powder.
    2 Rate given in terms of formulation if not indicated
      by a.i. = active ingredient.
    3 n.d. = non-detectable (varies 0.01-0.1 ppm).
    * Considered that the residue has not met the local requirements
      of good agricultural practice.
    It has been found (Brewerton et al., 1968) that the trichloronat
    residues in pasture crops were at or below 5 mg/kg (dry matter basis)
    after two weeks from treatment at 0.5 and 1 kg active ingredient per
    hectare, after one month from treatment at 2 kg a.i. per ha, and after
    two months from treatment at 4 kg a.i. per ha.

    Fate of residues

    General comments

    Trichloronat is a thiophosphonate which is highly effective against
    insects which live in or on soil (Homeyer, 1969). In crop protection,
    it is used only as a soil insecticide. The compound itself causes only
    slight depression of cholinesterase activity in vitro (Root et al.,
    1969) whilst, on the other hand, the trichloronat-oxone, formed by
    oxidation, has a strong anticholinesterase action. Trichloronat can be
    metabolized into O-ethyl-O(2,4,5-trichlorophenyl)-ethylphosphonate,
    2,4,5-trichlorophenol, O-ethyl-ethanephosphothioic acid,
    O-ethyl-ethanephosphonic acid, and ethanephosphonic acid. Degradation
    is effected mainly by splitting of the P-O-aryl bond with formation of
    2,4,5-trichloro-phenol and O-ethyl-ethanethiophosphonic acid. On
    account of its very low stability, the latter is further broken down

    at a fast rate to O-ethyl-ethanephosphonic acid and finally to
    ethanephosphonic acid.

    In animals

    No relevant data are available for the evaluation of trichloronat in
    the feed (e.g. pasture grass) of the domestic animals.

    In plants

    It is known from biological experiments that trichloronat does not
    have a systemic action. Chemical analysis showed (Möllhoff, 1968a)
    that the compound is able, to a limited extent to penetrate into the
    plant and to be translocated within it just as observed also for
    parathion and similar compounds. Despite massive trichloronat
    treatment, viz. application of 50 ppm to potted soil, the trichloronat
    concentration in the aerial plant parts of China cabbage after 14 days
    amounted to only 0.05 ppm. Later analyses of kohlrabi showed that
    following application as a soil drench or granular treatment as
    recommended, i.e. at 50 mg of active ingredient per plant, the maximum
    residue amounted to 0.2 ppm after 30 to 40 days; the concentration in
    the leaves was higher than in the edible root. In larger plants, e.g.
    cabbages or bananas, the compound does not move upwards to a
    sufficient extent to produce measurable concentrations (>0.01 ppm) in
    the aerial plant parts. In root vegetables, the bulk of the absorbed
    trichloronat is present in the peel. In an experiment in which lettuce
    was sprayed with trichloronat (not done commercially), the
    trichloronat residues decreased at the same rate as those of parathion
    (Möllhoff, 1968b).

    Plants can convert trichloronat to the oxone. Following massive
    treatment, the concentrations may reach levels equivalent to 5-10% of
    the respective trichloronat content. But no concentrations exceeding
    0.05 ppm have been found in any instance (Bayer, 1971). The oxone
    migrates at a fast rate in the plant. China cabbage grown in potted
    soil containing an initial concentration of 19 ppm of oxone absorbed
    so much of the oxone after two to seven days that the concentration in
    the plants reached a level of 0.77 ppm (Möllhoff, 1968a). But in
    comparison with trichloronat, the oxone is broken down in the plant at
    a much faster rate (Möllhoff, 1968b).

    When trichloronat is broken down in the plant, 2,4,5-trichlorophenol
    is liberated. Very small concentrations of this metabolite were found
    in tobacco and beets (Bayer, 1971). A further study of the metabolism
    of trichloronat in plants is still in progress.

    In soil

    A study was undertaken by Tu (1970) to establish whether trichloronat
    has any effect on microbial activities related to soil fertility.
    Application of trichloronat to soil at rates of 10 and 100 ppm

    affected the populations of bacteria and fungi for periods of one and
    two weeks. The application did not have a permanently harmful effect
    on nitrification, sulfur oxidation and phosphorus mineralization. On
    the other hand, it significantly stimulated ammonification. There are
    indications that trichloronat like other organo-phosphorus
    insecticides undergo microbial degradation in soil. Harris (1969)
    compared the persistence of biological activity of insecticides,
    including trichloronat, in soil. The insecticides were divided into
    three groups: (1) highly residual; (2) moderately residual; and (3)
    slightly residual. In muck soil, trichloronat was classified into
    group (3) and in sandy loam it was placed into group (2). According to
    the results of experiments with granular formulations and emulsions in
    the United States of America and in Germany (Bayer, 1971), the
    concentration of trichloronat in soil decreases to a level of 50%
    within 50 to 115 days. Bro-Rasmussen et al. (1970) studied the
    persistence of organophosphorus insecticides in soil in Denmark, and
    found that trichloronat has a half-life of 141 days.

    The metabolites were found to reach their peak concentrations in soil
    30 to 60 days after incorporation of the parent compound.
    Trichloronat-oxone was not detectable (limit of determination of 0.01
    ppm) in non-planted soil in any study. Oxone has been found in soil
    only in one experiment on potted China cabbage (Möllhoff, 1968a) in
    which there was a trichloronat concentration of 50 ppm in the soil.
    When the experiment was terminated after 14 days, the oxone
    concentration had reached a level of 0.05 ppm. In a parallel
    experiment in which the oxone itself was applied into the soil, the
    oxone concentration decreased from 19.3 ppm to a level of 0.4 ppm in
    14 days. Therefore, it seems unlikely that the oxone is concentrated
    in soil.

    Splitting of the P-O-ethyl bond of trichloronat or its oxone was not
    observed in soil samples (limit of determination of 0.01 ppm). The
    2,4,5-trichlorophenol which is liberated by the splitting of the
    P-O-aryl bond reached concentrations averaging 0.3 ppm in soil (Bayer,
    1971; Möllhoff, 1971a; see Table II). The simultaneously liberated
    O-ethyl-ethanethiophosphonic acid was detected in traces only under
    favourable laboratory conditions and following addition of 40 ppm of
    trichloronat to soil. In a field experiment with a starting value of
    5.5 ppm of trichloronat, O-ethyl-ethanephosphonic acid and
    ethanephosphonic acid reached maximum concentrations of 0.1-0.15 ppm
    each (Table II). Ethane-thiophosphonic acid was not found in any
    instance. In the above-mentioned laboratory experiment in which 40 ppm
    of trichloronat was applied to the soil, the peak concentration of
    O-ethyl-ethanephosphonic acid was 0.2 ppm and that of ethanephosphonic
    acid was 1.2 ppm. Under laboratory conditions, the latter has in soil
    a half-life of 15 to 20 days, as against a half-life of about 50 days
    for trichloronat.



                        EtO   S      EtO   O       HO   S       HO   O              EtO   S      EtO   O     HO   S       HO  O
                          \ //         \ //         \ //         \ //                 \ //         \ //       \ //         \ //
              Days         P            P            P            P         HO-R       P            P          P            P
    Soil      after       / \          / \          / \          / \                  / \          / \        / \          / \       Total P
    No.       applic.   Et   O-R     Et   O-R     Et   O-R     Et   O-R             Et   OH      Et   OH     Et  OH       Et  OH      (%)

    1             0      5 510         n.d.         n.d.          n.d.       180      n.d.         60          n.d.          90         100
                 14      4 400         n.d.         n.d.          n.d.       200      n.d.        140          n.d.         110          78
    Opladen      31      4 860         n.d.         n.d.          n.d.       250      n.d.         80          n.d.          50          75
                 60      2 340         n.d.         trace         n.d.       280      n.d.         80          n.d.         130          40
                 89      2 050         n.d.         n.d.          n.d.        50      n.d.        <10          n.d.         100          36
                119      1 120         n.d.         n.d.          n.d.        70      n.d.        <10          n.d.          60          20
                150        890         n.d.         n.d.          n.d.        40      n.d.        <10          n.d.          30          15
                180        990         n.d.         n.d.          n.d.        nd      n.d.         nd          n.d.          nd          18

    2             0      2 670         n.d.         n.d.          n.d.        90      n.d.         20          n.d.          30         100
                 14      2 700         n.d.         n.d.          n.d.       100      n.d.         20          n.d.          30         105
    Höfchen      31      2 760         n.d.         n.d.          n.d.        30      n.d.         20          n.d.          40         109
                 60      2 350         n.d.         n.d.          n.d.       100      n.d.         30          n.d.          50          91
                 89        770         n.d.
                119        790         n.d.
                150      1 060         n.d.
                180        900         n.d.


    n.d. non detectable

    Assuming that trichloronat is applied, according to the
    recommendations, only once a year to the same field and taking into
    account the degradation rates presented before, there seems to be no
    accumulation of trichloronat in the soils to be expected.

    The behaviour of trichloronat in simulated field environment was
    studied to determine its relative potential for contaminating water
    stores. Residues in runoff water from field soil plots were less than
    1% within a 14-day interval of application. Leaching studies in the
    laboratory for high nitrogen, clay and sandy loam soils indicated that
    rainfalls of 368, 447 and 103 inches, respectively, would
    theoretically be required to leach the compound 12 inches into the
    soil (Shaw et al., 1971). The half-life of trichloronat in neutral or
    alkaline water is very short. It was found to be 51 hours in water
    buffered to a pH of 7 at 30°C (Shaw et al., 1971). Measurements in
    isopropanol/water 1:1 (v/v) at pH 11.5, equivalent to pH 10.5 in
    water, produced a half-life of 6.2 hours for trichloronat at 37°C; the
    half-life value found for parathion was 28.3 hours, and thus greater
    by a factor of 4.5 (Hofer, 1969). A similar factor, viz. 5.5, was
    obtained by Möllhoff (1971b) in measurements in distilled water at
    26°C. The half-life values were 110 days for parathion and paraoxone,
    50 days for parathion-methyl, 20 days for trichloronat and
    paraoxone-methyl, and 60 days for trichloronat-oxone.

    In storage and processing

    Residues of trichloronat, trichloronat-oxone and 2,4,5-trichlorophenol
    in cold-stored (approximately -20°C) cabbage and potatoes did not
    decrease in 168 to 224 days (Chemagro Corp., 1968). Kohlrabi roots
    containing 0.3 ppm of trichloronat were boiled unpeeled for 30 minutes
    in twice the amount by weight of water in a closed vessel, and then
    analysed together with the water. Twenty-seven per cent of the
    compound was decomposed (Bayer, 1971). Washed carrots contained 0.35
    ppm of residue; after they had been peeled, no more residue was
    detectable in them (limit of determination of 0.07 ppm) (Bayer, 1971).
    Washed turnips, carrots and onions contained no detectable residues
    after being peeled (Anon., Finland, 1969). The peel of carrots
    contained 0.66 ppm of residue as against only 0.02 ppm in the pulp.
    After these carrots had been mechanically washed, the peel was found
    still to contain 0.32 ppm residue and the pulp contained 0.04 ppm of
    residue. After the carrots had been blanched for one minute at 100°C,
    no more residues were detectable in them (<0.02 ppm). A similar
    result was obtained for normal preservation (Martens, 1970). In a
    study to investigate the effect of processing on trichloronat in sugar
    beets, a laboratory procedure was employed which simulated the
    industrial process; the results showed that trichloronat,
    trichloronat-oxone, and 2,4,5-trichlorophenol were completely degraded
    during the first initial boiling and liming step (Katague and
    Anderson, 1968a). Cigarettes containing trichloronat,
    trichloronat-oxone and 2,4,5-trichlorophenol were smoked and the smoke
    was analysed. Approximately 15% of each of the three compounds was
    found in the smoke (Olson and Anderson, 1968).

    Evidence of residues in food in commerce or at consumption

    From 1964 to 1968, Renvall and Åkerblom (1971) analysed 2396 samples
    of domestic and imported fruit and vegetables obtained from the
    Swedish market. Only about 0.01% of these samples, i.e. two or three,
    contained trichloronat. The residue level was less than 0.1 ppm. The
    limit of determination was 0.01 ppm. In 1968, Krause and Kirchhoff
    (1969, 1970) carried out analyses of market samples of fruit and
    vegetables produced in or imported into Germany. None of the 70
    analysed samples contained detectable residues of trichloronat (limit
    of determination of 0.01 ppm).

    Methods of residue analysis

    Studies of metabolites have shown that following customary application
    of trichloronat, the oxone will occur, if at all, only in low
    concentrations because its half-life is considerably shorter than that
    of the parent compound (Möllhoff, 1968a, 1968b), 2,4,5-trichlorophenol
    also occurs only in very low concentrations or not at all. Therefore,
    determination of the parent compound itself is sufficient for
    regulatory purposes.

    Renvall and Åkerblom (1971) developed a thin-layer chromatographic
    method for determining residues of organophosphorus insecticides,
    including trichloronat, in fruit and vegetables, and which has a limit
    of determination of 0.1 ppm.

    Trichloronat can also always be co-determined by multiresidue methods
    for gas-chromatographic determination of organophosphorus
    insecticides, which are suitable for determining parathion (Beckman
    and Garber, 1969; Krause and Kirchhoff, 1970; Möllhoff, 1967, 1968b;
    Renvall and Åkerblom, 1971; Sans, 1967). Detectors that have been used
    include the electron-capture detector (Brewerton at al., 1968;
    Möllhoff, 1967), the thermionic detector and the flame photometric
    detector (Bowman and Beroza, 1970).

    There are two special methods for the determination of trichloronat
    residues. One is based on the determination of the phenol group
    (Katague and Anderson, 1966), and the other is based on the
    determination of the parent compound itself (Möllhoff, 1967; 1968a,

    In the method based on the determination of the phenol, trichloronat
    and its oxone are determined together and the free
    2,4,5-trichlorophenol is determined separately. After separating the
    free 2,4,5-trichlorophenol, trichloronat and its oxone are saponified.
    The resultantly liberated phenol and the previously separated phenol
    which is already free are separately acetylated and determined by
    gas-chromatography using an electron-capture detector. The limit of
    determination is generally 0.01 ppm. For confirmation of the results,

    two columns (Katague and Anderson, 1968b) is used. In a study
    conducted by Katague and Anderson (1967), 43 organophosphorus
    pesticides were checked for possible interference with the
    trichloronat residue analysis method. The trichloronat analysis is
    interfered with only by fenchlorphos (Ronnel) and its oxygen analogue
    (they were not included in the above study) because they contain the
    same phenol as trichloronat.

    The second special method of trichloronat residue analysis with
    terminal gas-chromatographic determination permits trichloronat and
    its oxygen analogue to be detected separately with the phosphorus or
    the electron-capture detector. By using suitable columns, it was
    possible to separate trichloronat from 35 organophosphorus
    insecticides including fenchlorphos (Ronnel). The response of the
    electron-capture detector to trichloronat is three times greater than
    that of the thermionic phosphorus detector but interference peaks
    occur on concentrating the extracts of some crops. Organochlorine
    compounds may also interfere. Therefore, the phosphorus detector
    should be preferably used for the determination.

    The metabolites that cannot be assayed by either of these two methods,
    can be determined in soil and plant samples by a gas-chromatographic
    method described by Möllhoff (1970).

    Examples of national tolerances


                                                 Tolerance      Safety
    Country        Crop                          in ppm         interval
                                                                in days

    Belgium        Cabbage                                      60
                   Carrots                                      90
                   Fruit, vegetables (incl.
                   cabbage, onions), excl.
                   potatoes                      0.1
    Canada         Cole crops                    N.R.
    Denmark        Onion, cabbage and carrot
                   seed (as seed dressing)                      0
    Finland        General (as soil drench)                     84
    Italy          General                                      20
    Netherlands    Cabbage (soil treatment)                     42
                   Beans                         0
                   Cabbage, leeks, onions        0.1
                   Miscellaneous                 0
    Norway         Edible root crops
                   (as granular)                                90


    Trichloronat is an organothiophosphorus insecticide which is used
    against soil insects, especially vegetable fly larvae.

    It is chiefly recommended for treatments of onions, leeks, brassica
    crops, carrots, cereals, bananas and grassland. Types of application
    are seed dressing, granular broadcast, soil spray, transplant and soil
    drench. Amounts applied are up to 5 kg active ingredient per hectare.

    Technical trichloronat is reported to contain 93-95% active
    ingredient. Dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin) may exist
    as an impurity in the technical material. It is guaranteed by the sole
    manufacturer that the dioxin content is below the limit of detection
    of the analytical method (0.1 ppm).

    Residue data are available from several countries.

    Trichloronat is subject to degradation in soils, plants and animals.
    Prom the degradation products trichloronat-oxone is of toxicological
    importance, but it is existing only in insignificant amounts in the
    terminal residues.

    From the treated seeds or soil, trichloronat is sorbed to the surface
    of the plant roots and is migrating only in minor amounts into the
    aerial parts of the crops. From the root crops, carrots have shown
    highest incidence and magnitude of residues. It has been demonstrated
    that peeling, blanching, etc. processes decrease the residues of
    carrots and other root crops to or below the levels of analytical
    detection limits.

    There is a TLC method with a detection limit of 0.1 ppm, GLC
    multi-residue methods, and two specific methods with detection limits
    of about 0.01 ppm for determining the residues of trichloronat in
    various crops.

    The evaluation of residue data is based on the assumptions that the
    technical trichloronat contain less than 0.1 ppm dioxin and that it is
    applied only into soils or to seeds and no treatments of the growing
    crops are made. Any such treatments are not regarded as good
    agricultural practice.

    Since no residues have been detected (less than 0.01 ppm) in bananas
    and cereals from recommended usages no tolerances are needed for those

    Since an acceptable daily intake for trichloronat was not established
    by the Meeting, no recommendations for tolerances are made.

    As a result of recommended use of trichloronat, following residue
    levels need not be exceeded:

              Onions, leeks, kohlrabi, radish           0.5 ppm

              Cabbage, cauliflower, broccoli,
                brussels sprouts, rutabagas,
                turnips, sugar beets, potatoes          0.1 ppm

              Carrots                                   1 ppm

    Further work or information

    Required (before an acceptable daily intake can be established or
    tolerances recommended):

    1.   Information on the absorption, distribution, excretion and
         general metabolism of trichloronat in at least one mammalian

    2.   Comprehensive information on the gross and histopathological
         findings particularly after long-term administration of this

    3.   Relevant data for the evaluation of trichloronat in the feed of
         domestic animals, e.g. fodder crops.


    Anon., Finland. (1969) State Institute of Agr. Chem., Helsinki,

    Bayer AG, Farbenfabriken, Pflanzenschutz. (1969) (R)Phytosol,
    (R)Agritox (Bayer 37289, S 4400). Leverkusen. E. 1-659/23536

    Bayer AG, Farbenfabriken, Pflanzenschutz. (1971) Documentation on
    trichloronat for FAO

    Beckman, H. and Garber, D. (1969) Recovery of 65 organophosphorus
    pesticides from Florisil with a new solvent elution system.
    J.A.O.A.C., 52, 286-293

    Bowman, M. C. and Beroza, M. (1970) GLC retention times of pesticides
    and metabolites containing phosphorus and sulfur on four thermally
    stable columns. J.A.O.A.C., 53: 499-508

    Brewerton, H.V., Gibbs, M. M. and Perrot, D. C. F. (1968)
    Fensulgothion and "Bayer 37 289" residues in pasture. New Zealand
    J. Agr. Res., 11: 303-312

    Bro-Rasmussen, F., Noddegaard, E. and Voldum-Clausen, K. (1970)
    Comparison of the disappearance of eight organophosphorus insecticides
    from soil in laboratory and in outdoor experiments. Pesticide Sci.,
    1: 179-199

    Chemagro Corporation, Research Dept., Kansas City, U.S.A., Rep. No. 23
    060. (1968) The effect of frozen storage at 0 to -10°F on Bay 37 289.
    Residues in cabbage and potatoes

    DuBois, K. P. (1963) The acute oral toxicity of Bayer 37289 to
    chickens. Unpublished report of the Toxicity Lab., University of
    Chicago, submitted by Farbenfabriken Bayer

    DuBois, K. P. and Kinoshita, F. (1963) The acute toxicity of Bayer
    37289 to mammals. Unpublished report of the Toxicity Lab., University
    of Chicago, submitted by Farbenfabriken Bayer

    DuBois, K. P., Kinoshita, F. and Flynn, M. The sub-acute parenteral
    toxicity of Bayer 37289 to rats. Unpublished report of the Toxicity
    Lab., University of Chicago, submitted by Farbenfabriken Bayer

    Gaines, T. B. (1969) Acute toxicity of pesticides. Toxicol. appl.
    Pharmacol., 14: 515-534

    Grey, A. P., Hibbs, C. M. and Nelson, D. L. (1969) Histologic
    evaluation of Bayer 37289 treated rats - addendum to report of Root et
    al., 1968a. Unpublished report of Chemagro Corp. submitted by
    Farbenfabriken Bayer

    Harris, C. R. (1969) Laboratory studies on the persistence of
    biological activity of some insecticides in soils. J. Econ. Entomol.,
    62: 1437-1441

    Hibbs, C. and Nelson, D. L. (1968) Microscopic findings in tissues of
    male and female dogs fed Bay 37289 for twelve weeks - addendum to
    report of Root et al., 1968b. Unpublished report of Chemagro Corp.
    submitted by Farbenfabriken Bayer

    Hobik, H. P. (1967) Histologische Untersuchungen. Unpublished report
    submitted by Farbenfabriken Bayer

    Hofer, W. (1969) Farbenfabriken Bayer A.G. Personal communication

    Homeyer, B. (1969) Trichloronat, ein neues Mittel gegen Bodeninsekten.
    Mededelingen Rijksfakulteit Landbouw-Wetenschappen Gent, 34: 598-606

    Katague, D. B. and Anderson, C. A. (1966) A gas-chromatographic method
    for the determination of Bay 37 289, its oxygen analogue, and
    2,4,5-trichlorophenol in crops. J. Agr. Food Chem., 14: 505-508

    Katague, D. B. and Anderson, C. A. (1967) An interference study for
    the residue method for Bay 37 289, its oxygen analog, and
    2,4,5-trichlorophenol. Chemagro Corp. Report No. 20 482. Unpublished

    Katague, D. B. and Anderson, C. A. (1968a) Effect of processing on Bay
    37 289 residues in sugar beets. Chemagro Corp. Report No. 23 418.

    Katague, D. B. and Anderson, C. A. (1968b) Data for a confirmatory gas
    chromatographic method for Bay 37 289 and its metabolites. Chemagro
    Corp. Report No. 23 427. Unpublished

    Kimmerle, G. (1962) Re 54400 (E37289). Unpublished report submitted by
    Farbenfabriken Bayer

    Kimmerle, G. (1965) Untersuchungen zur Neurotoxitat von Bayer 37289
    bei Huhnen. Unpublished report submitted by Farbenfabriken Bayer

    Kimmerle, G. (1968) Bayer 37289. Toxikologische Untersuchunger
    No. 667, submitted by Farbenfabriken Bayer

    Krause, C. and Kirchhoff, J. (1969) Organophosphatrückstände auf
    Marktproben von Obst und Gemüse sowie auf Getreideerzeugnissen.
    Nachrichtenblatt Dtsch. Pflanzenschutz-dienst, Braunschweig,
    21: 81-84

    Krause, C. and Kirchhoff, J. (1970) Gaschromatographische Bestimmung
    von Organophosphatrückständen auf Marktproben von Obst und Gemüse.
    Dtsch. Lebensmittel-Rundschau, 66: 194-199

    Löser, E. (1966) Subchronische toxikologische Untersuchungen an
    Ratten. Unpublished report submitted by Farbenfabriken Bayer

    Löser, E. (1968) Subchronische toxikologische Untersuchungen an
    Ratten. Unpublished report submitted by Farbenfabriken Bayer

    Löser, E. (1970) Chronisch toxikologische Untersuchungen an Ratten.
    Unpublished report submitted by Farbenfabriken Bayer

    Löser, E. (1971) Bay 37289 Generationsversuche an Ratten. Unpublished
    report submitted by Farbenfabriken Bayer

    Martens, P. H. (1970) Influence des traitements de conserverie sur la
    degradation des residus de pesticides appliques sur carottes. Faculté
    des Sciences Agronomiques de L'Etat, Gembloux, Belgique; Centre de
    Recherches de Phytopharmacie, Rapport d'Activite 1970, No. 706

    McCollister, D. D. Lockwood, D. T. and Rowe, V. K. (1961) Toxicologic
    information on 2,4,5-trichlorophenol. Toxicol. appl. Pharmacol.,
    3: 63-70

    Möllhoff, E. (1967) Gaschromatographische Bestimmung von Rückständen
    in Pflanzen und Bodenproben nach Anwendung von Präparaten der
    (R)E 605-Reihe und von (R)Agritox. Pflanzenschutz-Nachrichten
    "Bayer", 20: 557-574

    Möllhoff, E. (1968a) Versuche zur Aufnahme von Agritox durch Pflanzen
    aus dem Boden. Farbenfabriken Bayer A.G. Unpublished

    Möllhoff, E. (1968b) Beitrag zur Frage der Rückstände und ihrer
    Bestimmung in Pflanzon nach Anwendung von Präparaten der (R)E
    605-und (R)Agritox-Reihe. Pflanzenschutz-Nachrichten "Bayer", 21:

    Möllhoff, E. (1970) Methods zur Extraktion aus Pflanzen und Boden, zur
    Trennung und zum gaschromatographischen Nachweis von
    Organophosphorverbindungen und ihren Um- und Abbau-produkten.
    Vorläufiger Bericht. Farbenfabriken Bayer A.G. Unpublished

    Möllhoff, E. (1971a) Untersuchung über den Metabolismus von
    Trichloronat im Boden. Farbenfabriken Bayer A.C. Unpublished

    Möllhoff, E. (1971b) Verhalten einiger Organophosphorverbindungen in
    destilliertem Wasser. Farbenfabriken Bayer A.G. Unpublished

    Olson, T. J. and Anderson, C. A. (1968) Determination of Bay 37 289
    residues in cigarette smoke. Chemagro Corp. Report No. 23 066.

    Ragab, M. T. H. (1967) Direct fluorescent detection of
    organothiophosphorus pesticides and some of their sulfur-containing
    breakdown products after thin layer chromatography. J.A.O.A.C.,
    50: 1088-1098

    Renvall, S. and Åkerblom, M. (1971) Determination of organophosphorus
    pesticide residues in fruits and vegetables on the Swedish market from
    1964 to 1968. Residue Reviews, 34: 1-26

    Root, M., Kinoshita, F. K., Flynn, M. and DuBois, K. P. (1969)
    Toxicity and anticholinesterase action of O-ethyl
    O-2,4,5-trichlorophenyl ethylphosphonothioate. Toxicol. appl.
    Pharmacol., 14 (3): 620. Abstr. Papers 18th Ann. Meet. Soc.
    Toxicol., Williamsburg, Virginia

    Root, M., Meskauskas, J. Kinoshita, F. and Flynn, M. (1970) The
    chronic toxicity of Bayer 37289 to male and female dogs. Unpublished
    report of the Toxicity Lab., University of Chicago, submitted by
    Farbenfabriken Bayer

    Root, M., Meskauskas, J., Kinoshita, F., Flynn, M. and Kempf, C.
    (1968a) Sub-acute oral toxicity of Bayer 37289 to male and female
    rats. Unpublished report of the Toxicity Lab., University of Chicago,
    submitted by Farbenfabriken Bayer

    Root, M., Meskauskas, J., Kinoshita, F., Flynn M. and Groks, D.
    (1968b) Sub-acute oral toxicity of Bay 37289 to male and female dogs.
    Report of the Toxicity Lab., University of Chicago, submitted by
    Farbenfabriken Bayer

    Sans, W. W. (1967) Multiple insecticide residue determination using
    column chromatography, chemical conversion, and gas-liquid
    chromatography. J. Agr. Food Chem., 15: 192-198

    Shaw, H. R., Flint, D. R. and Waggoner, T. B. (1971) Bay 37 289
    - Water stability and soil runoff, leaching and adsorption studies.
    Chemagro Corp. Report No. 29 062. Unpublished

    Tu, C. M. (1970) Effect of four organophosphorus insecticides on
    microbial activities in soil. Appl. Microbiol., 19: 479-484

    See Also:
       Toxicological Abbreviations