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    WORLD HEALTH ORGANIZATION            FOOD AND AGRICULTURE ORGANIZATION
    ORGANISATION MONDIALE DE LA SANTE    ORGANISATION POUR L'ALIMENTATION      
                                         ET L'AGRICULTURE

                                         WHO/VBC/DS/87.74
                                         ORIGINAL: ENGLISH
                                         Distr.:   LIMITED


    DATA SHEET ON PESTICIDES No.  74

    PHOSPHAMIDON




    CLASSIFICATION:

    Primary Use: Insecticide

    Secondary Use: Acaricide

    Chemical Group: Organophosphorus compound



         It must be noted that the issue of a Data Sheet for a
    particular pesticide does not imply endorsement of the pesticide by
    WHO or FAO for any particular use, or exclude its use for other
    purposes not stated. While the information provided is believed to
    be accurate according to data available at the time when the sheet
    was compiled, neither WHO nor FAO are responsible for any errors or
    omissions, or any consequences therefrom.

    The issue of this document does    Ce document ne constitue pas une
    not constitute formal              publication. Il ne doit faire
    publication. It should not be      l'objet d'aucun compte rendu ou
    reviewed, abstracted or quoted     résumé ni d'aucune citation sans
    without the agreement of the       l'autorisation de l'Organisation
    Food and Agriculture               des Nations Unies pour
    Organization of the United         l'Alimentation et l'Agriculture
    Nations or of the World Health     ou de l'Organisation Mondiale de
    Organization.                      la Santé.

    1.0  GENERAL INFORMATION

    1.1  COMMON NAME:   Phosphamidon  (ISO, BSI and ANSI)

    1.1.1 Identity:

          IUPAC: 2-chloro-2-diethylcarbamoyl-1-methylvinyl dimethyl 
          phosphate

          CAS: 2-chloro-3-(diethylamino)-1-methyl-3-oxo-1-propenyl
          dimethyl phosphate 

          CAS Reg. No.: 297-99-4 (trans-isomer), 23783-98-4 
          (cis-isomer), 13171-21-6 (mixture) 

          Molecular formula: C10H19ClNO5P

          Molecular weight: 299.70

          Structural formula:
          
    Chemical Structure

    1.1.2 Synonyms: Phosphamidone; Famfos; DimecronR; DixonR; C-570; 
          Ciba-570; ENT 25,515; ML-97; Or-1,911 

    1.2  SYNOPSIS: Phosphamidon is a noncumulative systemic 
         organophosphorous pesticide with a broad spectrum of activity: It 
         is a cholinesterase inhibitor with rapid contact and stomach 
         action. The technical product is very highly toxic to mammals and 
         is listed in WHO Hazard Class Ia. 

    1.3  SELECTED PROPERTIES

    1.3.1 Physical characteristics - Phosphamidon is a pale yellow to 
          colorless oily liquid with a faint odour.  It has a boiling point 
          of 162°C at 1.5 mmHg; a density (d)254  of 1.2132 and a refractive 
          index (n)20D of 1.4721. Phosphamidon exists as a mixture of 70% 
          cis-isomer and 30% trans-isomer and is corrosive to iron, 
          tinplate and aluminium. 

    1.3.2 Solubility - Phosphamidon is miscible with water.  It is soluble 
          in aromatic hydrocarbons but insoluble in non-polar aliphatic 
          hydrocarbons. 

    1.3.3 Stability - It is stable in neutral and acid media but is 
          hydrolyzed by alkali; halflife at 23°C is 13.8 days at pH 7 and 
          2.2 days at pH 10.  Phosphamidon decomposes above 160°C. 

    1.3.4 Vapour pressure - 2.5 x 10-5 mmHg.

    1.4  AGRICULTURE, HORTICULTURE AND FORESTRY

    1.4.1 Common formulations - Available as 20-100% soluble concentrates 
          (from 200 to 1000 g a.i./l in 2-propanol), as 0.5g/kg granules 
          and in U.L.V. formulations.  The granules are in WHO Hazard Class 
          II (moderately hazardous). 

    1.4.2 Pests controlled - These include sap-feeding insects, sugar cane 
          and rice stemborers and rice leaf beetles. 

    1.4.3 Use pattern - Phosphamidon is used on citrus and cotton crops, 
          deciduous fruit and nut crops at rates of 300-600 g a.i./ha for 
          sap-feeding insects and 500-1000 g a.i./ha for other pests. 

    1.4.4 Unintended effects - Phosphamidon is highly toxic to bees.  It is 
          non-phytotoxic except to some cherry and sorghum varieties. 

    1.5  PUBLIC HEALTH USE - No recommended use.

    1.6  HOUSEHOLD USE - No recommended use.

    2.0  TOXICOLOGY AND RISKS

    2.1  TOXICOLOGY - MAMMALS

    2.1.1 Absorption route - Phosphamidon may be readily absorbed from the 
          gastrointestinal tract, through the intact skin and by inhalation 
          of spray mists and dusts. 

    2.1.2 Mode of action - Phosphamidon is a cholinesterase inhibitor.  An 
          impurity in the technical product, gamma-chlorphosphamidon, 
          inhibits mammalian cholinesterases 10 to 20 times more than pure 
          phosphamidon. 

    2.1.3 Excretion products - Metabolism and excretion is rapid in 
          mammals.  After ip injection of 32P-labelled phosphamidon to 
          rats, 60% of the dose was recovered in 24 hours.  In rats and 
          goats, oxidative metabolism yielded mostly desethyl phosphamidon, 
          phosphamidon amide and deschloro-phosphamidon.  However over 90% 
          of radioactivity in the urine was in the form of nontoxic 
          unextractable polar metabolites. 

    2.1.4 Toxicity, single dose -

          Oral LD50:

              Rat            17 mg/kg b.w.
  
              Mouse          10 mg/kg b.w.

                              6.5 mg/kg b.w. (cis-isomer) 

                            220 mg/kg b.w. (trans-isomer)

              Dog            50 mg/kg b.w.

              Rabbit         32 mg/kg b.w.

          Onset of poisoning is extremely rapid.  Clinical signs include 
          hypersalivation, lacrimation, miosis, dyspnea, vomiting,
          ataxia, convulsions, tetany and opisthotonos.

          Dermal  LD50:

              Rat           374 mg/kg  b.w.

          Inhalation LC50:
                            
              Rat           102 mg/m3/4h (head only exposure)

              Rat           135 mg/m3/4h (whole body exposure)

              Rat           160 mg/m3/4h

              Mouse          33 mg/m3/4h

              Guinea pig   1300 mg/m3/4h

          I.P. LD50:

              Rat             9.2 mg/kg b.w.

              Mouse           5.8 mg/kg b.w.

          I. V. LD50:

              Mouse           6 mg/kg b.w.

          Most susceptible species - No appreciable species variability 
          has been found among the animals tested. 

    2.1.5 Toxicity, repeated doses -

          Oral:  Male rats (5/group) were administered 2.5, 5.0 or 10 mg/kg 
          b.w./day of 83% phosphamidon by stomach tube.  All rats at 5 and 
          10 mg/kg b.w./day died after 1-33 days.  Similarly all rats given 
          daily oral doses of 5 and 10 mg/kg b.w. of 20% phosphamidon in 
          isopropanol died within 41 days.  One of five rats at 2.5 mg/kg 
          b.w./day died during a ten-week period. 

          Rats were dosed daily by stomach tube with 0.3 or 3.0 mg/kg b.w. 
          phosphamidon in propylene glycol.  At 3 mg/kg b.w. serum 
          cholinesterase activity was reduced by 14% and brain 
          cholinesterase was reduced by 12.5% after one dose.  After seven 
          and 14 days treatment, the inhibition was 42.5 and 37% in serum 
          and 55 and 67.5% in brain respectively.  In rats left undosed for 
          a further seven days, brain cholinesterase activity remained 
          inhibited at 47.5%. The no-effect level was reported to be 0.3 
          mg/kg b.w./day. 

          Daily oral doses of phosphamidon of 1.08 mg (approximately 68 
          mg/kg b.w.) in adult female rabbits for 30 days did not reveal 
          any significant clinical symptoms of toxicity.  Higher levels of 
          2.16 mg of phosphamidon (approximately 1.35 mg/kg b.w.) resulted 
          in overt toxicity in a 15 day treatment period.  Treated animals 
          showed morphological changes in liver, kidney, adrenal and brain, 
          and haemoglobin and erythrocyte levels increased.  Cholinesterase 
          activity was inhibited in erythrocytes and brain by 72.05 and 
          84.15% respectively. 

          Daily oral doses of phosphamidon in rabbits resulted in one of 
          three animals dying at 3.5 mg/kg b.w. (in 21 days), two of three 
          animals dying at 7 mg/kg b.w. (in eight days), and total 
          mortality of five animals at 15 mg/kg b.w. within seven days. 

          Dermal: Rabbits dosed with 0.1, 0.25 or 0.5 ml/kg b.w. of a 12% 
          solution of phosphamidon for six weeks showed erythema and oedema 
          in increasing incidence, thought to be solvent related.  Other 
          toxic signs included hyperpnoea, hypersalivation, tremor and 
          ataxia at the two highest dose levels.  Inhibition of blood and 
          brain cholinesterases was significant in males and females at 
          0.25 ml/kg level with the exception of brain cholinesterase 
          activity in females which appeared unaffected at 0.25 ml/kg 
          level.  No effect level: 0.1 ml/kg (0.019- mg a.i./kg b.w.). 

          Inhalation:  Wistar rats exposed to a continuous flow of air 
          containing 0.05 or 0.5 mg/m3 of phosphamidon for four hours 
          daily, five times a week, for 42 days suffered a temporary 
          inhibition of erythrocyte cholinesterase.  No effect on 
          mortality, behaviour, haematology, clinical chemistry or 
          pathology was observed. 
        
          Intravenous: In a 14 day experiment, rabbits survived dally 
          injections of 3 mg/kg b.w. phosphamidon whereas 2/3 mortality was 
          observed at 7.5 mg/kg b.w. 
         
    2.1.6 Dietary studies -

          Short term: Dogs fed phosphamidon at 0, 0.05, 0.1, or 2.5 mg/kg 
          b.w./day in capsule form for three months did not show any ill 
          effects except in the highest dose group.  Decreases in body 
          weight gain, in food consumption in females, in haematology 
          parameters, as well as an increase in GTP in males and 
          inhibitions of blood and brain cholinesterases for both sexes 
          occurred at the highest dose level.  No other findings were 
          noted. 

          No effect level: 0.1 mg/kg/b.w./day.

          Long term: Two year feeding studies: No effect levels:

                    Rat   1.25 mg/kg b.w./day

                    Dog   0.1  mg/kg b.w./day

          A 5 mg/kg b.w./day dose in rats caused significant weight 
          depression while moderate clinical symptoms, attributable to 
          cholinesterase inhibition, occurred at a dose level of 2.5 mg/kg 
          b.w./day in dogs. 

    2.1.7 Supplementary studies of toxicity -

          Carcinogenicity: When Osborne-Mendel rats were fed dietary levels 
          of 80 or 160 mg/kg diet phosphamidon was found to give equivocal 
          results.  In B6C3F1 mice fed similar dietary levels of 
          phosphamidon, no evidence of carcinogenicity was indicated. 

          Teratogenicity: No information available.

          Reproduction: No information available.

          Mutagenicity: Phosphamidon has been shown to demonstrate 
          clastogenic effects in in vivo tests with bone marrow cells of 
          rats and mice.  It has also been shown to be capable of inducing 
          genetic damage in in vitro human lymphocyte studies and in vivo 
          host mediated assays and micronuclei tests.  Phosphamidon was not 
          mutagenic in metabolically activated or non-activated systems of 
          mouse lymphoma cells (L5178Y/TK+/-), or Salmonella typhimurium.
          Phosphamidon was mutagenic only in metabolically activated 
          systems of Saccharomyces cerevisiae D7, exerted slight 
          clastogenic activity in a Chinese hamster-nucleus anomoly test at 
          levels over 5 mg/kg but was not mutagenic in sister chromatid 
          exchange assays using Chinese hamster bone marrow cells (10 
          mg/kg).  No DNA damage was induced in systems utilizing rat 
          hepatocytes and human fibroblasts. 

          Neurotoxicity: No published information available.

    2.1.8 Modifications of toxicity - The cis-isomers of phosphamidon and 
          its desethyl metabolite were found to be approximately 40 times 
          more toxic than the trans-isomers. N-deethylation of phosphamidon 
          increases its toxicity. 

          In acute studies, no potentiation occurred between equal 
          quantities of phosphamidon and other organophosphorus 
          insecticides (dimethoate, endothion, ethion, malathion, 
          mevinphos, oxydemeton-methyl, and parathion. 

    2.2  TOXICOLOGY - MAN

    2.2.1 Absorption - Phosphamidon may be absorbed from the 
          gastrointestinal tract, through the intact skin and by inhalation 
          of spray mists and dusts. 

    2.2.2 Dangerous doses -

          Single: Phosphamidon has been given a toxicity rating of 5 
          (Gosselin), the probable oral lethal dose is 5-50 mg/kg b.w. 
          Temporary acceptable daily intake for man: 0-0.001 mg/kg b.w. 

          Repeated: No information available.

    2.2.3 Observations on occupationally exposed workers - Two operators 
          were completely drenched with 50% phosphamidon and six others 
          were splashed.  Following a thorough wash, symptoms of gastric 
          pains, headache and burning sensation in the eyes were reported 
          with uneventful recovery. 

    2.2.4 Observations on exposure of the general public - No information 
          available. 

    2.2.5 Observations on volunteers - Thirty two people (10-70 years old) 
          remained in paddy fields during and one hour after ULV 
          phosphamidon aerially sprayed at 550 g/ha.  The unprotected 
          volunteers, exposed to twice the recommended rate of compound, 
          experienced conjunctival irritation.  Plasma cholinesterase 
          levels were depressed 0-25% in 19 people, 26-50% in 19 other 
          people and over 50% in two people with complete recovery in nine 
          days.  Erythrocyte cholinesterase was not affected. 

          [Editors note: Inhibition of plasma cholinesterase is an accepted 
          sign of exposure as in this case intoxication is related to 
          inhibition of erythrocyte cholinesterase.]

    2.2.6 Mishaps - In one suicidal poisoning, an apneic and cyanotic 18-
          year-old girl survived six days before severe bilateral 
          bronchopneumonia caused her death.  Autopsy revealed brain and 
          liver injury but investigators concluded that anoxia may have 
          been a factor in tissue injury. 

          A 10 year-old boy ingested between 60 and 120 mg/kg b.w. of 20% 
          phosphamidon.  Recovery was rapid following the use of an emetic. 

    2.3  TOXICOLOGY - NON-MAMMALIAN SPECIES

    2.3.1 Fish - Low toxicity to fish.

           LC50:  (24 hr)  Fathead minnows      4.8  mg/l

                           Rainbow trout        4.4  mg/l

           LC50:  (96 hr)  Rainbow trout     3.2-20  mg/l
           (technical
             product)        Crucian carp       600  mg/l

                             Channel catfish    360  mg/l

                             Bluegill           150  mg/l

                             Guppy               54  mg/l

    2.3.2 Birds   -

          Acute Oral LD50:

            Mallard duck (F)        3.81 mg/kg b.w. 80% in water

            Mallard duck (F)        3.05 mg/kg b.w. 80% in isopropanol

            Chukar partridge (M,F)  9.07 mg/kg b.w. 80% in isopropanol

            Pigeon (M,F)             2-3 mg/kg b.w. 80% in isopropanol

            Mourning dove (M,F)      2-4 mg/kg b.w. 80% in isopropanoglycol

            Whitewing dove (M,F)      26 mg/kg b.w. 85% in isopropanol

          Acute Dermal LD50:

            Mallard duck (F)          26 mg/kg b.w. 85% in propylene

          Eight Day Feeding Study LD50:

           Technical Product:

            Wildbirds  (five species)    3.16-5.62 mg/kg

            Other species                 2.1-14.0 mg/kg

            Pheasant                           0.8 mg/kg

          Eight Day Feeding Study LC50:

            Peking Ducks           918.0 mg/l

            Japanese Quails        1612.0 mg/l


           Dietary Studies:

           In a 100 day study, 50% mortality in young and adult birds was 
           observed at dietary levels of 1-100 and 10-200 mg/kg 
           respectively.  Treatment of chick embryos with phosphamidon (1
           mg per egg) resulted in growth retardation and malformations in 
           the head, and neck regions.  Limb buds and eyes were also 
           adversely affected.  Complete agenesis was seen in some organs 
           such as eyes at higher doses (2 and 20 mg per egg). 

    2.3.3 Other species - Phosphamidon is highly toxic to bees.

    3.0  FOR REGULATORY AUTHORITIES - RECOMMENDATIONS ON REGULATION OF 
         COMPOUND

    3.1  RECOMMENDED RESTRICTIONS ON AVAILABILITY

         (For definitions of categories, see the Introduction to Data Sheets) 

         All formulations 85% and over are placed in Category 1

         All other available formulations are placed in Category 2

    3.2  TRANSPORTATION AND STORAGE -

         Formulations in category 1 and 2:  Should be transported or stored 
         in clearly labelled rigid and leakproof containers and away from 
         containers of food and drink.  Storage should be under lock and 
         secure from access by unauthorized persons and children. 

    3.3  HANDLING

         Formulations in category 1 and 2:  Full protective clothing (see 
         part 4) should be used by all those handling the compound.  
         Adequate washing facilities should be available close at hand. 
         Eating, drinking and smoking should  be  prohibited  during  
         handling  and before washing after handling. 

    3.4  DISPOSAL AND/OR DECONTAMINATION OF CONTAINER - Container must be 
         either burned or crushed and buried below topsoil.  Care must be 
         taken to avoid subsequent contamination of water sources.  
         Container may be decontaminated (for method see paragraph 4.3 of 
         Part 4) but should not be used for food or drink. 

    3.5  SELECTION, TRAINING AND MEDICAL SUPERVISION OF WORKERS -

         Formulations in category 1 and 2:  Pre-employment and periodic 
         medical examination for workers desirable. Workers suffering from 
         active hepatic  or  renal  diseases  should  be excluded from 
         contact.  Pre-employment and cholinesterase tests for workers are 
         desirable except for those handling only 0.5g/kg  granules.  
         Special  account  should  be taken of workers' ability to 
         comprehend and  follow  instructions.  Training  of  workers in 
         techniques to avoid contact is essential. 

    3.6  ADDITIONAL REGULATIONS RECOMMENDED IF DISTRIBUTED BY AIRCRAFT -

         All formulations: Pilot and loaders should have special training 
         in application methods and early symptoms of poisoning.  Flagmen, 
         if used, should wear overalls and a broad brimmed hat and, be 
         located well away from the dropping zone. 

    3.7  LABELLING -

         All formulations, minimum cautionary statement:

                            "DANGER - POISON"

                    (skull and cross bones insignia)

         Phosphamidon is an organophosphorous compound which inhibits 
         cholinesterase.  It is of very high toxicity.  Contact with the 
         skin, inhalation of dust or spray, or swallowing may cause illness 
         or be fatal.  Wear protective gloves, and clean protective 
         clothing, when handling this material.  Bathe immediately after 
         work.  Ensure that containers are stored under lock and key.  
         Empty containers must be disposed of in such a way as to prevent 
         all possibility of accidental contact with them.  Keep the 
         material out of reach of children and well away from foodstuffs, 
         animal feed and their containers. 

         In case of contact, immediately remove contaminated clothing and 
         wash the skin thoroughly with soap and water, for eyes, flush with 
         water for 15 minutes.  If poisoning occurs, call a physician.  
         Atropine and oximes are accepted antidotes; repeated doses may be 
         necessary.  Artificial respiration also may be needed. 

    3.8  RESIDUES IN FOOD - Maximum residue levels have been recommended by 
         the Joint FAO/WHO Meeting on Pesticide Residues. 

    4.0  PREVENTION OF POISONING IN MAN AND EMERGENCY AID

    4.1  PRECAUTIONS IN USE

    4.1.1 General - Phosphamidon is an organophosphorous pesticide of 
          extremely high mammalian toxicity.  It is readily absorbed 
          through the intact skin, from the gastrointestinal tract and by 
          inhalation of dust or spray mist.  Repeated exposure may have a 
          cumulative effect on cholinesterase levels.  Most formulations 
          should be handled by trained personnel wearing protective 
          clothing. 

    4.1.2 Manufacture and formulation - TLV - No information.  Closed 
          systems and forced ventilation may be required to reduce, as much 
          as possible, the exposure of workers to the chemical. 

    4.1.3 Mixers and applicators - When opening the container and when 
          mixing, protective impermeable boots, clean overalls, and gloves 
          should be worn.  Mixing, if not mechanical, should always be 
          carried out with a paddle of appropriate length.  When spraying 
          tall crops or during aerial application, a face mask should be 
          worn, as well as an impermeable hat, clothing, boots and gloves.  
          The applicqror should avoid working in spray mist and avoid 
          contact with the mouth.  Particular care is needed when equipment 
          is being washed after use.  All protective clothing should be 
          washed immediately after use, including the insides of gloves.  
          Splashes must be washed immediately from the skin, or eyes, with 
          large quantities of water.  Before eating, drinking, or smoking, 
          hands and other exposed skin should be washed. 

    4.1.4 Other associated workers (including flagmen in aerial operations)
          Persons exposed to phosphamidon and associated with its
          application should wear protective clothing and observe the 
          precautions described above in 4.1.3 under "Mixers and 
          applicators". 

    4.1.5 Other populations likely to be affected - With good application 
          practice, subject to 4.2  below, other persons are not likely to 
          be exposed to hazardous amounts of phosphamidon. 

    4.2  ENTRY OF PERSONS INTO TREATED AREA - Unprotected persons should be 
         kept out of tall crops for four days and out of other crops for at 
         least 24 hours. 

    4.3  DECONTAMINATION OF SPILLAGE AND CONTAINERS - Residues in 
         containers should be emptied in a diluted form into a deep pit, 
         taking care to avoid ground waters.  The empty container may be 
         decontaminated by rinsing two or three times with water and 
         scrubbing the sides.  An additional rinse should be carried out 
         with 5% sodium hydroxide solution which should remain in the 
         container overnight. Impermeable gauntlets should be worn during 
         this work, and a soakage pit should be provided for the rinsings.  
         The container should then be filled with water and allowed to 
         stand 24 hours.  Empty and repeat three times.  Decontaminated 
         containers should not be used for food, feed or drinking water.  
         Spillage of phosphamidon and its formulations should be removed by 
         rinsing with large quantities of water. 

    4.4  EMERGENCY AID

    4.4.1 Early symptoms of poisoning - Early symptoms of poisoning may 
          include excessive sweating, headache, weakness, giddiness, 
          nausea, vomiting, hypersalivation, stomach pains, blurred vision, 
          slurred speech and muscle twitching.  Later there may be 
          convulsions and coma. 

    4.4.2 Treatment before person is seen by a physician, if these symptoms 
          appear following exposure - The person should stop work 
          immediately, remove contaminated clothing and wash the affected 
          skin with soap and water, if available, and flush the area with 
          large quantities of water.  If swallowed, and if the person is 
          conscious, vomiting should be induced.  In the event of collapse, 
          artificial resuscitation should be given, bearing in mind that if 
          mouth-to-mouth resuscitation is used, vomit may contain toxic 
          amounts of phosphamidon. 

    5.0   FOR MEDICAL AND LABORATORY PERSONNEL

    5.1   MEDICAL DIAGNOSIS AND TREATMENT IN CASES OF POISONING

    5.1.1 General information - Phosphamidon is an organophosphorous 
          pesticide of extremely high mammalian toxicity which is active 
          against a variety of agricultural pests.  It is readily absorbed 
          from the gastrointestinal tract; through the intact skin; and, by 
          inhalation of dust or spray mist.  It is converted in vivo to the 
          oxygen analogues of phosphamidon which also inhibits 
          cholinesterase.  It does not accumulate in body tissues. 

    5.1.2 Symptoms and signs - Initial symptoms of poisoning may include 
          excessive sweating, headache, weakness, giddiness, nausea, 
          hypersalivation, vomiting, stomach pains, blurred vision, slurred 
          speech and muscle twitching. More advanced symptoms of poisoning 
          may be convulsions, coma, loss of reflexes and loss of sphincter 
          control. 

    5.1.3 Laboratory - The most important finding is reduction of activity 
          of whole blood or erythrocyte cholinesterase. Urinary levels of 
          organic phosphorus containing metabolites may also be used as a 
          measure of exposure. Neither method is specific for phosphamidon. 

    5.1.4 Treatment - If the pesticide has been ingested, unless the 
          patient is vomiting, rapid gastric lavage should be performed 
          using 5% sodium bicarbonate if available.  For skin contact, the 
          skin should be washed with soap and water. If the compound has 
          entered the eyes, they should be washed with large quantities of 
          isotonic saline or water.  Persons without signs of respiratory 
          inefficiency but with manifest peripheral symptoms should be 
          treated with 2-4 mg of atropine sulfate by intravenous injection 
          and 1000 mg pralidoxime chloride or 250 mg of toxogonin (adult 
          dose) by slow intravenous injection.  More atropine may be given 
          as needed. Persons with severe intoxication, with respiratory 
          difficulties, convulsions and unconsciousness should immediately 
          be given atropine and a reactivator.  In such severe cases 4-6 mg 
          of atropine sulfate should be given initially followed by 
          repeated doses of 2 mg at 5-10 minute intervals.  Diazepam may be 
          given to control convulsions.  The patient's condition including 
          respiration, blood pressure, pulse frequency, salivation, and 
          convulsions should be carefully observed as a guide to further 
          administration of atropine.  If the patient is cyanotic, oxygen 
          should be given at the same time as atropine sulfate.  The 
          airways should be kept free and artificial resuscitation should 
          be applied if required, preferably by mechanical means.  If 
          necessary, intubation should be performed.  Contraindications are 
          morphine, barbiturates, phenothiazine, tranquillizers (except 
          Diazepam) and central stimulants of all kinds.  Pralidoxime and 
          toxogonin alone are not regarded as effective antidotes in 
          phosphamidon poisoning. 

    5.1.5 Prognosis - If the acute toxic effect is survived and adequate 
          artificial resuscitation has been given if needed, the chances of 
          complete recovery are good.  However, in very severe cases, 
          particularly if artificial resuscitation has been inadequate, 
          prolonged anoxia may give rise to permanent brain damage. 

    5.1.6 References of previously reported cases - Phosphamidon has been 
          implicated in several cases of pesticide poisoning, see Gitelson, 
          S. et al., (1965) Br. J. Ind..Med., 22 236-239. 

    5.2  SURVEILLANCE TESTS

         Test                          Normal    Action    Symptomatic
                                       level*    level*      level*

         Plasma cholinesterase          100%      50%       variable

         Whole blood or erythrocyte     100%      70%       usually 40%
           cholinesterase

         * Expressed as percentage of pre-exposure values


    5.3  LABORATORY METHODS

    5.3.1 Detection and assay of compound - Thin-layer chromatography and 
          gas-liquid chromatography methods have been used to analyse 
          phosphamidon in technical products and in its formulations.  
          Analysis of residues in plant and animal tissues - gas 
          chromatography and flame photometry methods. 

    5.3.2 Other tests in case of poisoning - Levels of cholinesterase in 
          the blood, particularly plasma, provide the most useful diagnosis 
          of poisoning. 

          Michel, N. O. (1949), J. Lab. Clin. Med., 34, 1564-1568

          Ellman, G. L. et al. (1961), Biochem. Pharmacol., 7, 88-95.

          Measurement of urine metabolites may also be determined in order 
          to given indication of exposure for methods.  See section 5.3.1, 
          Detection and Assay. 







See Also:
        Phosphamidon (ICSC)
        Phosphamidon (PIM 454)