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

                                        VBC/DS/84.58
                                        ORIGINAL: ENGLISH


   DATA SHEET ON PESTICIDES No.  58

   CYPERMETHRIN


    CLASSIFICATION:
    Primary use: Insecticide
    Secondary use:
    Chemical group: Pyrethroid

    Date issued:



         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     rsum 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 Sant.

    

    1.   GENERAL INFORMATION

    1.1  COMMON NAME: Cypermethrin (ISO, BSI and BPC)

    1.1.1 Identity:

          IUPAC: (RS)--cyano-3-phenoxybenzyl (1RS)-cis,trans-3-(2,2-
          dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate 


          CAS No. 1: (RS)-cyano (3-phenoxyphenyl)methyl (1RS)-cis,trans-
          3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate

          CAS Reg. No.: 52315-07-8

          Molecular formula: C22H19Cl2NO3      Molecular weight: 416.32

          Structural formula:

    Chemical Structure

    1.1.2 Synonyms: BarricadeR; CCN 52; CymbushR; ImperatorR;   
          KafilR; NRDC 149; OMS 2002; PP 383; RipcordR; WL 43467 

    1.2  SYNOPSIS: Cypermethrin is a composite pyrethroid; a broad 
         spectrum, non-cumulative insecticide; and, a fast-acting 
         neurotoxin with good contact and stomach action.  It is of 
         moderately high toxicity to mammals and readily metabolized with 
         immediate loss of activity.  Cypermethrin is not a plant systemic, 
         it is readily degraded on soil or plants but has good residual 
         activity on inert surfaces. 

    1.3  SELECTED PROPERTIES

    1.3.1 Physical characteristics - The pure isomers are colourless 
          crystals, the technical material is a viscous yellow-brown
          semi-solid. The melting points are 60-80C. 

    1.3.2 Solubility - In water at 21C, 0.01-0.2 mg/l; in hexane at 20C, 
          103 g/l; soluble in acetone, cyclohexane, ethanol, xylene and 
          chloroform. 

    1.3.3 Stability - Cypermethrin is quite stable at temperatures under 
          220C; photodecomposition has been observed in field tests, with 
          no reduction in biological performance.  The optimum stability 
          occurs at pH 4 while decomposition occurs under alkaline 
          conditions. 

    1.3.4 Vapour pressure - 5.07 x 10-9 kPa (3.8 x 10-8 mmHg) at 70C.

    1.4  AGRICULTURE, HORTICULTURE AND FORESTRY

    1.4.1 Common formulations - Emulsifiable concentrates of various 
          concentrations, 25-400 g a.i./l; ULV for agronomic use, 10-75 g
          a.i./l; for veterinary purposes, e.c. 25-200 g/l; and, wettable 
          powder at 125 g/kg. 

    1.4.2 Pests controlled - Active against a wide range of insect pests, 
          particularly leaf and fruit eating Lepidoptera, Coleoptera and 
          Hemiptera; cattle ectoparasites, sheep scab, lice and ked. 

    1.4.3 Use pattern - Cypermethrin may be applied to a wide range of 

          fruit, vegetables, vines, tobacco, and several non-food crops. It 
          should be applied when pests first appear at rates of 25-150 g 
          a.i./ha. For Hemiptera control, foliar or soil treatment at 100 
          g/ha is effective.  For cattle use 150 mg/l baths and for sheep 
          10 mg/l dips may be used.  Good control of biting insects may 
          also be maintained by direct spraying of the animals or the 
          structural surfaces of animal housing. 

    1.4.4 Unintended effects - No cases of phytotoxicity have been 
          reported. 

    1.5  PUBLIC HEALTH USE - Cypermethrin may be used by professional 
         sprayers to control nuisance and disease vector insects in limited 
         areas. 

    1.6  HOUSEHOLD USE - No recommended use.

    2.   TOXICOLOGY AND RISKS

    2.1  TOXICOLOGY - MAMMALS

    2.1.1 Absorption route - Cypermethrin is primarily absorbed from the 
          gastrointestinal tract.  It may a so be absorbed by inhalation of 
          spray mist and only minimally through the intact skin. 

    2.1.2 Mode of action - Cypermethrin is a synthetic pyrethroid and a 
          permethrin analogue.  This group of chemicals acts primarily on 
          the basal ganglia of the central nervous system, causing 
          repetitive nerve action through prolongation of sodium 
          permeability during the recovery phase of the action potential of 
          neurons. 

    2.1.3 Excretion - The metabolism and elimination of cypermethrin have 
          been extensively studied in rats and mice and to some extent in 
          dogs and cows.  Both isomers are readily metabolized by liver 
          microsomal esterases and oxidases.  The cis-isomer is the more 
          stable of the two and may undergo extensive hydroxylation prior 
          to ester cleavage.  In most animals, except dogs, urine was the 
          major route of elimination (+80%); the faecal route was less 
          important; the skin and pulmonary routes were not significantly 
          involved.  The ester cleavage yielded cyclopropanecarboxylic acid 
          and 3-phenoxybenzoyl alcohol fragments.  The latter was oxidized 
          to 3-phenoxybenzoic acid (3-PBA) and partially hydroxylated at 
          position 4', and to a lesser extent at 5- and 6-sites.  The major 
          urinary excretion products in most species were 3-PBA as a free 
          acid and as conjugates of glucuronic and amino-acids; 4'-HO-3-PBA 
          as a free acid and as sulfates and glucuronides.  The acid moiety 
          is primarily excreted as a free acid and also as a glucuronide 
          following oxidation at the methyl sites and lactone 
          rearrangement.  The cyano group was relatively slowly excreted; a 

          small amount as an imino-thiazolidine-4-carboxylic acid salt was 
          rapidly excreted.  In dogs, over 80% of the ingested dose was 
          found in the faeces indicating possibly poor absorption.  In rats 
          and mice, only a small amount of unhydrolysed product was found 
          in faeces. Elimination of cypermethrin was rapid in most animals, 
          in most tissues the half-life was approximately one day; in 
          adipose tissue it ranged from 10 to 30 days. 

    2.1.4 Toxicity, single dose - The toxicity of cypermethrin varies  
          with the type of vehicle used, aqueous suspensions in general 
          were the least toxic and non-polar solutions the most toxic (e.g. 
          in corn oil the mouse LD50 is 82 mg/kg bw and for aqueous 
          suspensions it is over 750 mg/kg bw).  Also, since the cis-isomer 
          is almost 10 times as toxic as the trans-isomer the acute 
          toxicity of a mixture will be determined by the isomer ratio. 

                    Oral LD50:                      Technical material

          Rat (M, F)             303 mg/kg bw (cis:trans, 50:50, in dimethyl-sulfoxide)

          Mouse (M, F)           138 mg/kg bw (cis:trans, 50:50, in dimethyl-sulfoxide)

          Rabbit  (F)          +2400 mg/kg bw (cis:trans, 40:60, undiluted)

          Hamster -

           Syrian (M, F)        +400 mg/kg bw  (cis:trans, 50:50, in corn oil)

           Chinese (M, F)        203 mg/kg bw  (cis:trans, 50:50, in corn oil)

          Guinea-pig (M, F) 500-1000 mg/kg bw  (cis:trans, 50:50, in corn oil)

          Dermal LD50:

          Rat (F)              +4800 mg/kg bw  (cis:trans, 40:60, undiluted)

          Rat (M,  F)          +1600 mg/kg bw  (cis:trans, 50:50, in xylene)

          Rabbit  (F)          +2400 mg/kg bw  (cis:trans, 40:60, undiluted)

          I.P. LD50:

          Rat (F)               +500 mg/kg bw  (cis:trans, 40:60, aqueous suspension) 

          Mouse (M, F)           485 mg/kg bw  (cis:trans, 50:50, corn oil) 

                    In general pyrethroid poisoning is characterized by hyperactivity 
          and hypersensitivity (somatosensory). Cypermethrin in particular 
          is included among a group of compounds producing the CS-syndrome 
          in rodents, in sequence: pawing and burrowing behaviour, 

          salivation, coarse tremors progressing to choreoathetosis and 
          occasionally terminal clonic seizures.  Most susceptible species 
          possibly the mouse. 

    2.1.5 Toxicity, repeated doses:

          Oral: Studies on rats (25-200 mg/kg bw per day for five days) and 
          hamsters (5-30 mg/kg bw per day for five days) confirmed the 
          pattern of clinical signs of toxicity observed in single dose 
          studies.  These animals recovered within three to four weeks 
          after the initial treatment.  Hamsters showed fur loss and dermal 
          ulceration in the early stages of the study.  Further findings 
          are discussed in section 2.1.7 Neurotoxicity. 

          Dermal: There was a 20-30% mortality rate among rats given five 
          consecutive doses at 2500 and 5000 mg/kg bw per day.  Clinical 
          signs of toxicity and sciatic nerve degeneration were consistent 
          with the observations in oral studies.

          Cumulation of compound: The slow clearance rate from adipose 
          tissue after a single dose suggests a potential for 
          bioaccumulation in that tissue.  Other body tissues do not appear 
          to accumulate cypermethrin. 

          Cumulation of effect: No information available.

    2.1.6 Dietary studies

          Short-term: Male and female rats were fed 92% cypermethrin (44:56 
          cis:trans) at concentrations of 0, 75, 150 or 1500 mg/kg of diet 
          for 90 days.  No deaths occurred at any dose level.  At the 
          highest dose there was an initial decrease in growth rate and 
          food consumption which returned to normal after four weeks. 
          Increased hepatic microsomal oxidation activity was observed in 
          females at the highest dose and in males at the two highest 
          doses; complete recovery occurred in both sexes by the fourth 
          week after treatment ended. Female rats showed a dose-dependent 
          decrease in kidney weight which was significant at the highest 
          dose only.  No treatment-related gross or microscopic 
          abnormalities were observed in any body tissues or organs 
          (including the sciatic nerve) at any dose level. 

          In a second study, rats were fed cypermethrin (50:50) at 0, 25, 
          100, 450 or 1600 mg/kg of diet for 90 days. Mortalities occurred 
          among the males up to the fifth week at the highest dose level.  
          All the animals showed severe signs of neurotoxic poisoning at 
          this dose but the survivors progressively improved over the 
          remaining weeks of treatment.  Severe sciatic nerve damage was 
          seen in all of the rats that died during treatment; the survivors 
          showed no such effect after 90 days of treatment.  At the highest 

          dose level growth rates and food consumption declined; in 
          haematology - PCV and erythrocyte counts declined, especially 
          among the females.  No consistent treatment-related adverse 
          effects were observed at or below the 100 mg/kg diet level. 

          The cypermethrin no-effect-level for rats was observed to be 5.0 
          mg/kg bw per day. 

          In an additional experiment male and female rats were fed either 
          the trans-isomer (at 0, 30, 100, 300, 750 or 1500 mg/kg of diet) 
          or the cis-isomer (at 0, 30, 100, 300, 750 or 1500 mg/kg of diet) 
          for 35 days.  No mortalities occurred on the trans-isomer diet 
          while the cis-isomer caused extensive mortalities at the highest 
          dose.  No treatment-related clinical signs of neurotoxic 
          poisoning were observed in the trans-isomer treated group.  Growth 
          rates and food consumption declined while kidney and liver 
          weights increased at the highest dose.  The cis-isomer treated 
          rats showed severe signs of neurotoxic poisoning at the two 
          highest doses. The dead rats showed extensive coagulative 
          necrosis of hepatocytes and severe sciatic damage.  No central 
          nervous system damage was observed at any dose level of either 
          isomer. 

          Male and female dogs were fed cypermethrin at 0, 5, 50, 500 or 
          1500 mg/kg of diet for 90 days.  There were no mortalities.  At 
          the 1500 mg/kg dose, significant signs of toxicity were observed 
          including diarrhoea, anorexia, tremors, ataxia, incoordination 
          and hyperesthesia.  There were no consistent treatment-related 
          adverse effects at 500 mg/kg and below, and no adverse effects 
          were observed at 50 mg/kg.  No compound-related gross or 
          histopathological changes were found at any dose level. 

          The cypermethrin no-effect-level for dogs was observed to be 1.25 
          mg/kg bw per day. 

          Long-term: Male and female rats were fed cypermethrin 
          (50:50 cis:trans) in the diet at 0, 1, 10, 100 or 1000 mg/kg of 
          diet for two years.  There were no treatment-related mortalities 
          over the course of the study. At the highest dose level, the 
          growth rate and food consumption were depressed and the liver 
          weight increased.  There were no clinical signs of toxicity, no 
          evidence of clinical neuropathy or histological evidence of nerve 
          degeneration.  Chronic nephrosis was common to animals of all 
          dose groups but was not dose-related.  The incidence of tumours 
          in the treatment groups was not significantly greater than in the 
          controls.

          The cypermethrin no-effect-level for rats was observed to be 5.0 
          mg/kg bw per day. 


    2.1.7 Supplementary studies of toxicity

          Carcinogenicity: There was no evidence of increased incidence of 
          tumours in a single long-term cypermethrin diet study in rats.  
          This finding is supported by those of several special studies for 
          teratogenicity in a mouse standard host-mediated assay, several 
          microorganism assays with and without rat liver microsomal 
          activation, and a hamster chromosomal damage assay. 

          Teratogenicity:  No evidence of teratogenic potential was 
          observed in rats and rabbits given doses of up to 70 mg/kg bw per 
          day from day 6 to day 15 of gestation in rats or 30 mg/kg bw per 
          day from day 6 to day 18 of gestation in rabbits. 

          Reproduction: In two dominant lethal assays in mice there was no 
          observed dose-related evidence of either reduced implantations or 
          increased foetal deaths.  No gross or microscopic abnormalities 
          of the testes and epididymes were observed in the treated males.  
          In a three-generation study, following cypermethrin 
          administration at concentrations up to 500 mg/kg of diet, no 
          adverse effects on reproductive behaviour, fertility, gestation, 
          viability or lactation were observed. 

          Mutagenicity: Cypermethrin (with and without rat liver microsomal 
          activation) was not observed to be genetically active in a 
          mitotic gene conversion assay with S. cerevisiae; in a mutation 
          rate assay with E. coli and S. typhimurium (TA-1538) at 500 
          mg/plate doses; in a revertant gene assay with S. typhimurium
          (TA-1535, -1537, -1538, -98 and -100) at 1 mg/plate doses; and, 
          in a mouse host-mediated assay with S. cerevisiae at 25 and 50 
          mg/kg bw given orally.  It was also observed to be inactive in a 
          Chinese hamster chromosomal damage assay at 20 and 40 mg/kg bw, 
          given orally. 

          Neurotoxicity:  Cypermethrin administered orally to rats and 
          hamsters in high acute and subacute doses produced reversible 
          clinical signs of ataxia, behaviour changes and, histological and 
          chemical changes consistent with Wallerian degeneration.  Doses 
          below the lethal range did not produce lesions in the sciatic and 
          posterior tibial nerves.  There was no evidence of delayed 
          neurotoxicity in hens given 1.0 mg/kg bw doses of cypermethrin. 

          Primary irritation and sensitization: Moderate skin irritation 
          and mild eye irritation were produced by single applications of 
          undiluted technical cypermethrin in rabbits.  Cypermethrin was
          also observed to have a weak sensitization potential in 
          guinea-pigs. 

          Cardiovascular and respiratory system: Cypermethrin was observed 
          to attenuate the reflex control of respiration and the autonomic 

          control of circulation. 

          Metabolism: Cypermethrin did not induce either cytochrome P-450 
          or NADPH cytochrome C reductase activity in hepatocytes of male 
          Long-Evans rats following 50 mg/kg bw per day, orally for up to 
          12 days. 

    2.1.8 Modification of toxicity - Substances which depress or inhibit 
          liver microsomal enyzme activity will increase the toxicity of 
          cypermethrin, in particular, profenfos, sulprofos and DEF 
          significantly synergize the cis-isomer on cabbage looper larvae 
          and adult house flies. 

    2.2  TOXICOLOGY - MAN

    2.2.1 Absorption - Cypermethrin is primarily absorbed from the 
          gastrointestinal tract.  It may also be absorbed by inhalation of 
          spray mist and only minimally through the intact skin. 

    2.2.2 Dangerous doses

          Single: No information.

          Repeated:  No information.

    2.2.3 Observations on occupationally exposed workers - Urinary levels 
          of cyclopropanecarboxylic acid metabolite in spraymen during one 
          experimental spray trial were observed to be 0.4 g/ml or less.  
          In another trial, operators spraying with hand-held ULV apparatus 
          were found to have measurable cypermethrin residues on the 
          exposed parts of their bodies.  They showed no adverse effects.  
          The rate of dermal exposure ranged from 1.5 to 4.6 mg/hour, the 
          24 hour urine metabolite level was between 0.05 and 0.32 mg for 
          most subjects.  An estimate of approximately 3% of the total 
          dermal dose was absorbed and rapidly excreted. 

    2.2.4 Observation of the general public - No information available.

    2.2.5 Observation of volunteers - No information available.

    2.2.6 Mishaps - No information available.

    2.3  TOXICITY TO NON-MAMMALIAN SPECIES

    2.3.1 Fish

          LC50 (96 hr):     Salmon            2.0  g/l  technical
                            Brown trout       2.4  g/l  technical
          Lethal threshold  Salmon            2 .4 g/l  technical
          LC50 (24 hr):     Rainbow trout     25.0 g/l  technical

                            Rainbow trout     61.0 g/l 40% a.i. fomulated

    2.3.2 Birds

          Oral LD50:        Chicken (M, F)    +2000 mg/kg bw
                            Partridge (M, F)  +3000 mg/kg bw

    2.3.3 Other species - Cypermethrin is relatively toxic to bees.

          LC50 (9 hr):   Lobster         0.04 g/l
                         Shrimp          0.01 g/l

    3.   FOR REGULATORY AUTHORITIES - RECOMMENDATIONS ON REGULATION OF 
         COMPOUND

    3.1  RECOMMENDED RESTRICTIONS ON AVAILABILITY (For definition of 
         categories, see the Introduction to Data Sheets) 

         There are no solid formulations available. 

         Liquid formulations over 15%, Category 3. 

         Other liquid formulations, Category 4. 
     
    3.2  TRANSPORTATION AND STORAGE

         Formulations in categories 3 and 4 - 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 key and secure from access by children and other unauthorized 
         persons. 

    3.3  HANDLING

         Formulations in categories 3 and 4 - Full protective clothing (see 
         part 4) should be used by those handling concentrates.  Adequate 
         washing facilities should be available at all times and should be 
         close to site of handling.  Eating, drinking and smoking should be 
         prohibited during handling and before washing after handling. 

    3.4  DISPOSAL AND/OR CONTAMINATION OF CONTAINERS

         Formulations in categories 3 and 4 - Containers must be either 
         burned or crushed and buried below topsoil. Care must be taken to 
         avoid sudsequent contamination of water-sources.  Containers may 
         be decontaminated (for method see paragraph 4.3 in part 4).  
         Decontaminated containers should not be used for food and drink. 

    3.5  SELECTION, TRAINING AND MEDICAL SUPERVISION OF WORKERS

         Formulations in categories 3 and 4 - Workers suffering from 

         asthma, allergies and other respiratory disorders, and 
         cardiovascular disorders should be excluded from contact.  Persons 
         under medication with neuroactive drugs should avoid contact.  
         Special account should be taken of the workers' ability to 
         comprehend and follow instructions.  Training of workers in 
         techniques to avoid contact is essential.  Pre-employment and 
         periodic medical examinations are not required. 

    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 be located well away from the 
         dropping zone. 

    3.7  LABELLING

         Formulations in categories 3 and 4 - Minimum cautionary statement 
         - "WARNING - POISON" (skull and cross-bones insignia). 
         Cypermethrin is a pyrethroid pesticide; it may be poisonous if
         swallowed.  It may be inhaled as a dust or mist and it may be
         irritating to the skin and eyes.  Avoid skin contact.  Wash 
         thoroughly with soap and water after using the product.  Keep the
         material out of reach of children and well away from foodstuffs,
         animal feed and food containers.  If poisoning occurs, call a
         physician.  There are no specific antidotes. 

    3.8  RESIDUES IN FOOD

         Maximum residue levels - Maximum residue levels have been reco-
         mmended by the Joint FAO/WHO Meeting on Pesticide Residues. 

    4.   PREVENTION OF POISONING IN MAN AND EMERGENCY AID

    4.1  PRECAUTIONS IN USE

    4.1.1 General - Cypermethrin is a pyrethroid, and a neurotoxic agent of 
          variable toxicity to mammals depending on the vehicle.  It is 
          readily absorbed from the gastrointestinal tract; it may be 
          absorbed by inhalation of dust and fine spray mist but only 
          minimally through the intact skin.  The health hazard is 
          considerably diminished by the low concentrations of the active 
          ingredient in all formulations.  It is important that 
          concentrated formulations be washed immediately from the skin and 
          eyes. 

    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 a container and mixing,
          protective impermeable boots, clean overalls impermeable gloves,
          eye protection and a respirator should be worn.  Mixing, if not 
          mechanical, should always be carried out with a paddle of
          appropriate length.  Avoid contact to mouth and eyes.  Before
          eating, drinking or smoking, hands and other exposed skin should
          be thoroughly washed with alkaline soap. 

    4.1.4 Other associated workers (including flagmen in aerial operations)
          - Persons exposed to the compound and associated with its
          application should use good footwear and clean overalls, with
          head covers if indicated.

    4.1.5 Other populations likely to be affecteed - With good agricultural 
          practice, subject to section 4.2 below, other populations are 
          not likely to be exposed to hazardous amounts of the compound. 

    4.2  ENTRY OF PERSONS INTO TREATED AREAS - Though cypermethrin is 
         relatively persistent, low application rates ensure low residue 
         levels.  Unprotected persons may enter treated areas immediately 
         after spraying without being exposed to hazardous amounts of 
         cypermethrin.

    4.3  SAFE DISPOSAL OF CONTAINERS AND SPILLAGES -  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
         detergent and scrubbing the sides.  The hands should be protected
         during this work.  Decontaminated containers should not be used
         for food and drink.

    4.4   EMERGENCY AID

    4.4.1 Early symptoms of poisoning - Based on animal studies, these may
          include excessive salivation, nausea ana vomiting; shortness of
          breath and laboured breathing; coarse tremors, hypersensitivity 
          to external stimuli and general weakness; a burning or itching 
          sensation following contact; hypotension and slow heart rate.  
          These may be followed by hypertension, increased heart rate and 
          convulsive muscle contractions. 

    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 clean the affected 
          skin area.  First soak up any liquid remaining on the skin with 
          readily disposable material (e.g. talcum powder or absorbent 
          cloth or paper), wash the affected area with warm water and 
          alkaline soap. For eye contamination, wash with copious amounts
          of water.  Avoid exposing affected skin or eyes to bright light.
          If the material was swallowed and signs of toxicity are severe,

          induce vomiting if person is conscious and aspiration of vomit 
          can be avoided.  In the event of collapse, apply artificial
          respiration.  Keep in mind that if mouth to mouth respiration is
          used, vomit may contain toxic amounts of cypermethrin.  Keep the 
          person calm and comfortable. 

    5.   FOR MEDICAL AND LABORATORY PERSONNEL

    5.1  MEDICAL DIAGNOSIS AND TREATMENT OF POISONING

    5.1.1 General information - Cypermethrin is a pyrethroid pesticide of 
          moderate toxicity to mammals.  It is readily absorbed from the 
          gastrointestinal tract, by inhalation of dust and fine spray mist 
          and only minimally through the intact skin.  The hydrolysis and 
          oxidation products of metabolism are rapidly excreted in the 
          urine and faeces.  Cypermethrin is a neurotoxic agent most 
          probably acting through the central nervous system to cause 
          repetitive nerve activity. 

    5.1.2 Signs and symptoms - Little information is available on the acute 
          toxic effects of pyrethroids in humans.  Based upon animal 
          studies, high doses may cause repetitive activity in sensory and 
          motor nerves.  Early signs of poisoning may be: salivation, 
          irritability, tremors and ataxia; respiratory and cardiovascular 
          dysfunction may also occur.  In man, a burning and itching 
          sensation sometimes follow contact. 

    5.1.3 Laboratory - There are no established practical methods for 
          determining pyrethroids in body fluids.  Urinary levels of 3-
          phenoxybenzyl degradation products may be a useful index of 
          exposure.  In addition, the monitoring of sensory nerve action 
          potential and central nervous and cardiac activities (EEG and 
          ECG) may be useful in diagnosis and in assessment of therapy. 

    5.1.4 Treatment - There is no specific antidote, treatment must be 
          symptomatic.  Keep the patient warm and calm.  In cases of severe 
          intoxication, therapy should include a sedative and 
          anticonvulsant (e.g. barbiturates, diazepam, paraldehyde, etc.). 
          The use of antispasmodic drugs is of limited value; mephenesin 
          and atropine have been found to effectively alleviate the 
          symptoms of pyrethroid poisoning in laboratory animals.  If a 
          large quantity of the compound has been swallowed, unless the 
          patient is vomiting, gastric lavage should be performed using a 
          5% sodium bicarbonate solution, followed by powdered activated 
          charcoal.  For skin contact, soak up any liquid remaining on skin 
          with readily disposable absorbent material then wash the affected 
          area with warm water and alkaline soap.  If skin irritation 
          occurs treat with a soothing skin cream and avoid exposure to 
          direct light.  For eye contamination, wash the eye with 4% sodium 
          bicarbonate or any other non-irritating, alkaline aqueous 

          solution. 

    5.1.5 Prognosis - There have been no reports of overt symptoms 
          resulting from poisoning of man by cypermethrin; the prognosis 
          therefore is not known.  However, by analogy with laboratory 
          animals, it may be assumed that if the acute toxic effect is 
          survived the chances of complete recovery are good. 

    5.1.6 References to previously reported cases - No information.

    5.2  SURVEILLANCE TESTS - None

    5.3  LABORATORY METHODS - References only are given.

    5.3.1 Detection and assay of compound and residues - Chapman, R. A. &
          Harris, C. R. (1978) Journal of Chromatography, 166(2), 513-516. 
          Papadopoulou-Mourikidou, E., Iwata, Y. & Gunther, F. A. (1981) 
          J. Agric. Food Chem., 29(6), 1105-1111.  Siltanen, H. & 
          Rosenberg, C. (1980) Publ. State Inst. Agric. Chem. (Finland),
          Vol. 17, 61 pp.





See Also:
        Alpha-cypermethrin (UK PID)
        Cypermethrin (EHC 82, 1989)
        Cypermethrin (ICSC)
        Cypermethrin (PIM 163)
        Cypermethrin (UK PID)