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    WORLD HEALTH ORGANIZATION                 


    Original:  ENGLISH
    Distr.: LIMITED
    Date of issue:  February 1994

                               WHO/FAO DATA SHEET ON PESTICIDES

                                            No. 85


    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 

    The issue of this document does not constitute formal
    publication.  It should not be reviewed, abstracted or quoted
    without the agreement of the Food and Agriculture Organization
    of the United Nations or of the World Health Organization.

    Ce document ne constitue pas une publication.  Il ne doit faire
    l'objet d'aucun compte rendu ou résumé ni d'aucune citation
    sans l'autorisation de l'Organisation des Nations Unies pour
    l'Alimentation et l'Agriculture ou de l'Organisation Mondiale
    de la Santé.                                                 


    Primary use:           Insecticide
    Secondary use:         
    Chemical group:        Pyrethroid


    1.1   COMMON NAME:  phenothrin (BSI, E-ISO);  phénothrine (F-ISO).

    1.1.1  Identity

          d-Phenothrin is a mixture of four stereoisomers.  The technical 
          compound is a 20:80  cis:trans mix of both (1R) - (1S) - 
          configurations.  The (1R) - configurations have a greater 
          insecticidal activity than the corresponding (1S) - isomers.  d-
          Phenothrin, a preparation rich in (1R) - isomers, with a 
           cis:trans ratio 20:80, has been marketed.  Data pertaining to 
          this latter product will be designated d-phenothrin in this data 

          IUPAC chemical name:  3-phenoxybenzyl (1RS, 3RS;  1RS, 3SR)-2, 2-
          dimethyl-3-(2-methylprop-1-enyl) cyclopropanecarboxylate.  The 
          alternative nomenclature of (1RS)- cis ,  trans - has also been 
          used to designate the stereoisomers and will be used in this data 

          CAS chemical name:  Cyclopropanecarboxylic acid, 

          CAS registry number:       26002-80-2 (racemic).

          RTECS registry number:     GZ 1975000 (racemic)
                                       GZ 2002000 (d-phenothrin)

          Molecular formula:         C23H26O3

          Molecular mass:            350.5

          Structural formula:  

          Synonyms and trade names: (1R)-phenothrin;  S-2539, Multicide
          concentrate F-2271, WellcideR. The (1R)- cis ,  trans  
          (d-phenothrin); isomers (20:80) are known as SumithrinR;  
          S-2539 ForteR;  Pesguard-A NS, Pesguard-A NS W, or Pesguard NS. 
          The (R) - isomers may also be designated (+) or d-;  
          the (S) - isomers as (-) or 1-. 

    1.2   SYNOPSIS:  d-Phenothrin is a fast acting 
          insecticide, effective by contact and stomach action. It is 
          rapidly metabolized and excreted by mammals and has low mammalian 
          toxicity. Stable to storage in the dark;  relatively unstable to 
          sunlight or ultra violet irradiation, or in alkaline media. 


    1.3.1  Physical characteristics:  d-Phenothrin is a yellow 
          to yellow-brown liquid, with a density of 1.061 g/cm3 (25 °C) 
          and a refractive index of 1.5482. 

    1.3.2  Solubility:  Soluble in water (25 °C) 2 mg/L.  
          Soluble in organic solvents.

    1.3.3  Stability:  d-Phenothrin is hydrolysed by
          alkalis but is stable in neutral or weakly acidic media.  
          Unstable in most solvents except methanol, ethyl cellosolve, o-
          cresol and dimethylsulfoxide.  Unstable to ultra violet 
          irradiation and has a short residual life on pre-harvest 
          application.  However, d-phenothrin applied to wheat after 
          harvest showed only slight degradation after six months storage 
          at 30 °C.  When protected from light no breakdown of d-phenothrin 
          was observed after one year at room temperature. 

    1.3.4  Vapour pressure:  d-Phenothrin has a vapour
          pressure of 0.16 mPa at 20 °C. 


    1.4.1  Common formulations:  Water and oil based aerosols, 
          liquid concentrates, emulsifiable concentrates, powders and 
          dusts. May be formulated with synergists or with other pyrethroid 
          and non-pyrethroid insecticides. 

    1.4.2  Pests controlled:  Controls most  Lepidoptera,
           Hemiptera (bed bugs),  Diptera (flies, gnats, and mosquitos), 
          cockroaches and lice. 

    1.4.3  Use pattern:  d-Phenothrin is a non-systemic 
          insecticide which is effective by contact and as a stomach 
          poison. Used for power-spray, mist, thermal fog, aerosol and ULV 
          applications.  The major use of d-phenothrin is in the control of 
          nuisance insects and insects of importance to public health, and 
          it is used to control human lice, in which case it is formulated 
          as a powder, shampoo, or lotion.  It is also used to protect 

    1.4.4  Unintended effects:  Toxic to fish and bees.


          It is used for the impregnation of bednets and for aircraft 

    1.5.1  Common formulations:  As described in Section 
           1.4.1, but also formulated into powders, lotions and shampoos. 

    1.5.2  Pests mainly controlled:  See section 1.4.2.

    1.5.3  Use pattern:  Should be used according to 
          manufacturers' instructions on appearance of the pest. 


    1.6.1  Common formulations:  See Sections 1.4.1 and 1.5.1
          for general formulation details.

    1.6.2  Pests mainly controlled:  See Section 1.4.2.

    1.6.3  Use pattern:  See sections 1.4.3 and 1.5.3.



    2.1.1  Absorption route:  Absorbed from the 
          gastrointestinal tract and from the intact skin.  The dermal 
          absorption rate differs between the (1R)- cis - and the 
          (1R)- trans -isomers.  No data are available for the rate or
          extent of absorption from the lung. 

    2.1.2  Mode of action:  d-Phenothrin is a neuropoison.
          The symptoms of poisoning are typical of those of pyrethroids 
          without a cyano-substituent.  The proposed mechanism of action is 
          due to the reversible binding of d-phenothrin to the sodium 
          channels of the neuronal membrane, in this way modifying the 
          permeability of the membrane to ions. 

    2.1.3  Excretion products:  No published data are
          available for the combined isomers of d-phenothrin.  The 
          metabolism of the individual (1R)- cis - and (1R)- trans 
          - isomers has been investigated in the rat.  For both isomers an
          oral dose of 10 mg/kg b.w. was metabolized by hydrolysis,
          oxidation and conjugation and 96% of the administered dose was
          recovered in the urine and faeces within six days. 

          Following oral administration of the (1R)- trans - isomer, the 
          urine was the major excretory route.  The isomer was extensively 
          metabolized to oxidative and conjugated derivatives of the 
          hydrolysed ester.  Oxidative and conjugated derivatives of the 
          (1R)- cis -isomer were also observed but hydrolysis of the ester 
          linkage was a minor metabolic pathway.  With this isomer the 
          faeces was the major excretory route. 

          The metabolic profiles were similar following dermal application, 
          although the rates of excretion for each isomer showed some 
          differences between the two routes of administration. 

    2.1.4  Toxicity, single dose:
          Oral LD50
             Rat      >10,000 mg/kg b.w. (without vehicle)
             Rat      > 5,000 mg/kg b.w.
             Mouse    > 5,000 mg/kg b.w. (in corn oil)

         Dermal LD50
            Rat       >10,000 mg/kg b.w.

         Intraperitoneal LD50
            Rat       > 5,000 mg/kg b.w.
            Mouse     > 5,000 mg/kg b.w.

         Intravenous LD50
            Rat        452-492 mg/kg b.w.
            Mouse      354-405 mg/kg b.w.

            Rat       >10,000 mg/kg b.w.

            Rat       >10,000 mg/kg b.w.

            Rat       >10,000 mg/kg b.w.

         Inhalation LC50 - 4 hour exposure (1R)-phenotrin
            Rat       >3.76 g/m3
            Mouse     >1.2  g m3 (1-2 µm particulates in kerosene)
          No sex difference in the toxicity was reported.  Following 
          intravenous administration symptoms of poisoning included 
          fibrillation, tremor, slow respiration, salivation, lacrimation, 
          ataxia and paralysis. The symptoms appeared 0.5 - 1 hour after 
          administration and diminished spontaneously. 

          No histopathological findings in the nervous system were observed 
          following four hour inhalation exposure of rats to 3.76 mg/L (see 
          Section 2.1.7). 

    2.1.5  Toxicity, repeated dose:

          Inhalation:  Sprague Dawley rats or ddY mice exposed to
          concentrations of less than 0.21 mg (1R)-phenothrin/L, for 4 
          hours/day, five days/week for four weeks, showed no adverse 
          effect on behaviour, growth, clinical chemistry or organ 
    2.1.6  Dietary studies:

          Short term:  A 24 week dietary administration of up to 2500 mg 
          (1R)-phenothrin/kg diet to Sprague Dawley rats had no adverse 
          effect on growth, haematology, biochemical or histopathological 
          parameters.  Doses more than 5000 mg/kg diet produced increased 
          liver weights which were accompanied by histopathological changes 
          of an unspecified nature.  Rats and dogs receiving (1R)-
          phenothrin in the diet for six months showed no adverse effect at 
          1000 and 300 mg/kg diet, respectively. 

          Long term:  A dose related increased incidence of alveolar
          amyloidosis was observed in Swiss mice receiving 300-3000 mg d-
          phenothrin/kg diet for 18 months.  The increased liver weights 
          (both sexes) and a decreased growth rate (males) were observed at 
          3000 mg/kg diet. 

          No compound-related adverse effects were observed in rats 
          receiving up to 2000 mg d-phenothrin/kg diet for two years.  At 
          6000 mg/kg diet, growth was affected in both sexes.  Serum 
          glutamate-pyruvate transferase activity was increased in the 
          males of this dose group. 

    2.1.7  Supplementary studies of toxicity:

          Carcinogenicity:  No tumours attributable to d-phenothrin
          exposure were observed in Swiss mice following 18 months 
          administration of up to 3000 mg/kg diet, or in rats receiving 
          less than 6000 mg/kg diet in the long-term feeding studied 
          described above. 

         Teratogenicity: No teratogenic effects were observed.  The NOELs
          for New Zealand white rabbits and mice were 30 and 3000 mg/kg 
          b.w./day respectively. 

          Mutagenicity: Two oral doses of 1500 mg/kg b.w./day to male
          mice did not induce mutation in a host-mediated assay with
           Salmonella typhimurium -G46.  Similar investigations with 
          (1R)- trans -phenothrin (250 mg/kg b.w./day) or (1R)- cis 
          -phenothrin (90 mg/kg b.w./day) were also negative. 

          No mutagenic potential was observed with or without metabolic 
          activation of d-phenothrin, or the individual isomers, in several 
          strains of  S. typhimurium  or  Escherichia coli .  
          d-Phenothrin did not induce mutations in  Bacillus subtilis .
           In vivo  and  in vitro  chromosomal aberration tests showed 
          negative results. 

          Reproduction:  No significant changes in reproductive potential 
          were observed in a three generation reproduction study on Charles
          River rats.  The NOEL was 2000 mg/kg diet. 

          Neurotoxicity:  d-Phenothrin at high doses, in common with
          pyrethroids of similar chemical structure, may induce ataxia. 

          Rats receiving oral doses of 5000 mg (1R)-phenothrin/kg b.w./day 
          (as SumithrinR) for five days showed evidence of poisoning, 
          such as leg weakness or ataxia, and some died.  In survivors 
          three days after cessation of exposure no clinical signs of
          poisoning were apparent.  No significant morphological changes
          were observed. 

          Other:  (1R) - phenothrin had no effect on a variety of  in vitro
          and  in vivo pharmacological parameters.  These tests included  
          hexabarbital sleeping times in mice, body temperature in rats, 
          blood pressure and heart rate in dogs, and the contractile 
          activity of various muscle preparation  in vitro .
    2.1.8  Modifications of toxicity:  The geometric 
          isomers undergo different metabolic pathways (see Section 2.1.3). 
          The rapid hydrolysis of the  trans -isomers and the slower 
          oxidation of the  cis - isomers are similar to that observed with 
          other pyrethroids.  Inhibition of the oxidative enzymes may 
          increase the toxicity of the  cis  isomers. 

    2.2   TOXICOLOGY - MAN

    2.2.1  Absorption route:  No published data available but
          d-phenothrin may be absorbed from the skin, gastrointestinal 
          tract or from the lungs. 
    2.2.2  Dangerous doses:
          Single:    No published information available.
          Repeated:  No published information available.
    2.2.3  Observations on occupationally exposed workers:
          No published information available. 

    2.2.4  Observations on exposure of the general population:
          No published information available.  Manufacturers' instructions
          should be carefully followed to ensure that the general 
          population is not exposed to undue amounts of d-phenothrin during 
          agricultural, public health or domestic usage. 

    2.2.5  Observations on volunteers:  In a special 
          study, d-phenothrin in a talc powder formulation with Span 80 as 
          a stabilizer was applied to the head and pubic hair of eight male 
          volunteers three times at intervals of 3 days, at a dose of 32 
          mg/man per administration (0.44 to 0.67 mg/kg body weight per 
          day). The powder was washed off 1 hour after application.  There 
          were no significant abnormalities due to d-phenothrin in terms of 
          dermal irritation, clinical signs, or blood biochemical and 
          haematological parameters.  The blood levels of d-phenothrin were 
          below the detection limit of 0.0006 mg/kg. 

    2.2.6  Reported mishaps:  
          No published information available.


    2.3.1      Fish:  Toxic to fish.

         LC50 - 48 hour
            Goldfish         0.25 - 0.5 mg/L
            Killifish               0.2 mg/L 

         LC50 - 96 hour
            Bluegill         0.018 mg/L (1R)-phenothrin
            Rainbow trout    0.017 mg/L (1R)-phenothrin

    2.3.2  Birds:

         LD50 - Oral
            Bobwhite quail      > 2510 mg/kg b.w.

    2.3.3  Other species: 
          Toxic to bees but no quantitative data are available.

      LC50 3 hour
           Daphonia pulex     > 50 mg/L



          [For definition of categories see the 'Introduction to Data 
          Sheets']. Liquid formulations > 25% - Category 4* All other 
          formulations -  Category 5*

    Based on WHO documented oral LD50 of >5000 mg/kg b.w.


          Formulations in category 4:  Should be transported and stored in
          clearly labelled, leak-proof containers well away from food or 
          drink. The containers should be kept under lock and key, secure 
          from access by children and unauthorized personnel. 

          Formulations in category 5:  Should be transported and stored in
          clearly labelled, leak-proof containers, well away from food and 
          drink and secure from access by children. 
    3.3   HANDLING
          Formulations in category 4:  Protective clothing (see section 4)
          should be worn when handling these formulations.  Adequate 
          washing facilities should be available in the immediate area.  
          Eating, drinking and smoking should be prohibited during 
          handling.  Hands and face should be washed immediately after 
          handling the formulation. 

          Formulations in category 5:  Facilities as required for the 
          handling of any chemical should be provided.  Hands and face 
          should be washed before eating, drinking or smoking and 
          immediately after handling the compound. 

          Technical d-phenothrin and its formulations (other than 
          pressurized products):  Empty containers should be decontaminated 
          (See Section 4.3), but decontaminated containers must not be used 
          for transportation or storage of food or feed stuffs.  Containers 
          which are not decontaminated should be burned or crushed and 
          buried below topsoil.  Extreme care must be taken to ensure that 
          the disposal site will not cause subsequent contamination of 
          water sources. Pressurized products must be disposed of according 
          to manufacturers' instructions and the containers must never be 
          heated or punctured. 


          Formulations in category 4:  Persons under medication with
          neuroactive drugs should avoid contact with d-phenothrin.  
          Consideration should be given to the workers' ability to 
          comprehend and follow instructions.  Workers should be trained in 
          techniques to avoid contact with the formulations. 

          Formulations in category 5:  A warning to workers to avoid contact
          is essential.


          All formulations:  Pilots and loaders should have specialized
          training in application methods and in the recognition of early 
          symptoms of pesticide poisoning.  A suitable respirator should be 
          worn in addition to overalls and impermeable gloves.  Flagmen 
          should wear impermeable gloves and boots, overalls and a broad 
          brimmed hat and should be located well away from the dropping 

    3.7  LABELLING

          Formulations in category 4 - Minimum cautionary statement:  d-
          Phenothrin is a synthetic pyrethroid insecticide which may be 
          poisonous following ingestion, skin contact or inhalation of 
          fogs, dusts or mists.  These formulations may be irritating to 
          the skin and eyes.  Avoid skin contact;  wear protective 
          overalls, impermeable gloves and eye protection while handling 
          concentrate.  Keep the material out of reach of children and well 
          away from food and feed stuffs. If poisoning occurs call a 

          Formulations in category 5 - Minimum cautionary statement:  This
          formulation contains phenothrin and is poisonous if swallowed.  
          It may be absorbed from the skin or following inhalation of 
          dusts, mists or fogs.  Keep this product out of the reach of 
          children and well away from food and feed stuffs.  Wash 
          thoroughly after use. 


          Maximum residue limits have been established by the FAO/WHO Joint 
          Meeting on Pesticide Residues.  There are eight Codex Committees 
          MRLs.  The Joint FAO/WHO Meeting on Pesticide Residues has 
          estimated the Acceptable Daily Intake (ADI) to be 0.07 mg/kg body 



    4.1.1   General:  d-Phenothrin is a synthetic pyrethroid 
          which may elicit an effect on nerve function when administered at 
          high doses to animals.  It may be absorbed from the 
          gastrointestinal tract or from intact skin.  Absorption from the 
          lungs may occur following exposure to dusts, aerosol, mists or 
          fogs formulations. 

    4.1.2  Manufacture and formulation - TLV:  
          No published information available.  Closed systems and forced 
          ventilation should be used to reduce the exposure of workers to 
          d-phenothrin. Protective clothing (see Section 4.1.3) should be 

    4.1.3 Mixers and applicators:  Workers should wear
          impermeable gloves and boots, clean overalls and eye protection.  
          A respirator should additionally be worn during mixing operations 
          and when applying aerosol, mist, dust or fog formulations.  
          Mixing, if not mechanical, should always be carried out with a 
          paddle of appropriate length.  Avoid contact with the mouth, skin 
          and eyes. Before eating, drinking, or smoking, the face, hands 
          and exposed skin should be thoroughly washed. 

    4.1.4  Other associated workers:  Persons associated
          with the application of d-phenothrin should observe the 
          precautions described above (see sections 3.6 and 4.1.3). 

    4.1.5  Other populations likely to be affected:  
          The domestic and public health usage of d-phenothrin will expose 
          persons other than those associated with agricultural practices. 
          Careful attention to the manufacturers' instructions and the low 
          concentrations of d-phenothrin in many formulations should ensure 
          that this usage dose not expose the public to hazardous amounts 
          of d-phenothrin. 

          Good agricultural practices should ensure that the general public 
          are not exposed to hazardous amounts of d-phenothrin following 
          commercial applications. 


          Entry of unprotected persons into enclosed areas treated with 
          aerosol, mist or fog formulations should be prevented until the 
          area has been thoroughly ventilated.  

          Care must be taken during decontamination procedures to ensure 
          that water sources are not contaminated.  Impermeable gloves and 
          eye protection should be worn.  Residues in containers should be 
          emptied in a diluted form into a dry pit deeper than 0.5 m.  
          Dispose of pressurized products according to manufacturers' 
          recommendations.  These containers should not be punctured, 
          heated or burned.  For other products, the empty container may be 
          decontaminated by scrubbing with water and detergent followed by 
          soaking overnight with 5% sodium hydroxide solution. 
          Decontaminated containers must not be used for the transportation 
          or storage of food or drink. Containers which are not 
          decontaminated should be burned or crushed and buried below 

          Spillage of liquid formulations should be covered with absorbent 
          material.  This material, or spillage of dry formulations, should 
          be collected and burned or buried in a deep dry pit.  Residual 
          contamination should be removed from the spillage site by washing 
          with water and detergent. 


    4.4.1  Early symptoms of poisoning:  No reported 
          incidences.  Unless exposure to d-phenothrin has been 
          exceptionally high, the symptoms of over-exposure may be due to 
          the accompanying chemicals in the formulation.  Symptoms may 
          include headache, nausea and vomiting. 

    4.4.2  Treatment before person is seen by physician, if these
    symptoms appear following exposure:
          The person should stop work immediately, remove contaminated 
          clothing and wash the affected skin area.  If the formulation has 
          entered the eyes they should be flushed with clean water.  The 
          majority of formulations contain hydrocarbon solvents or oils.  
          Vomiting should not be induced unless it can be definitely 
          determined that all of the following apply:  that the formulation 
          was free of solvents and oil; that large amounts of the 
          formulation have been ingested;  that the patient is fully 
          conscious.  In all cases, keep the patient calm and obtain 
          immediate medical help. 



    5.1.1  General information:  d-Phenothrin is a synthetic 
          pyrethroid insecticide of low mammalian toxicity.  It may be 
          absorbed from the gastrointestinal tract;  by inhalation of 
          dusts, mists or fogs or through intact skin.  d-Phenothrin is 
          rapidly metabolized to hydrolysis and oxidation products, which 
          are rapidly excreted in the urine and faeces. 

    5.1.2  Symptoms and signs:  No published information
          available on the acute toxic effects of d-phenothrin in humans. 
          Accompanying chemicals in the formulation may elicit symptoms 
          before those observed from d-phenothrin exposure.  Early symptoms 
          may include headache, nausea and vomiting. 

    5.1.3  Laboratory:  There are no simple methods for 
          determining d-phenothrin in body fluids. The metabolism is rapid 
          and there are numerous excretory products.  The proportion of 
          each metabolite may not be constant in all types of exposure and 
          cannot therefore be used as a quantitative measure of exposure.  
          Some urinary metabolites may not be specific to d-phenothrin. 

    5.1.4  Treatment:  Treatment is symptomatic.  Wash 
          contaminated skin with soap and water. Wash contaminated eyes 
          with copious amounts of water.  Ingestion of a small amount (< 5 
          mg/kg b.w.) of d-phenothrin should be treated with a large dose 
          of activated charcoal followed by sodium or magnesium sulfate 
          (0.25 g/kg b.w.) in water. 

          Following ingestion of larger quantities of d-phenothrin, 
          vomiting should be induced if the patient is fully conscious.  
          Care must be taken however to avoid pulmonary complications from 
          the accompanying solvents or oils.  Subsequent administration of 
          activated charcoal may limit absorption of remaining d-

    5.1.5  Prognosis:  There are no published data 
          available.  Based on animal experiments it is expected that any
          effects should be reversible. 

    5.1.6  References to previously reported cases:  
          No published information available.

    5.2   SURVEILLANCE TESTS - None.


    5.3.1  Detection and assay of compound and residues:

          Papadopoulou-Mourkidou E, Iwata Y, Gunther FA (1984), J Agric 
          Food Chem 32: 800-805. 

          Sakaue S, Kitajima M, Horiba M, Yamamoto S (1981), Agric Biol 
          Chem 45(5): 1135-1140. 

    5.3.2  Other tests in case of poisoning:  None.


    1.    WHO (1990), Environmental Health Criteria 96;  d-Phenothrin;  
          Geneva, World Health Organization, 64 pp. 

    2.    WHO (1989), Health and Safety Guide 32;  d-Phenothrin;  Geneva, 
          World Health Organization, 28 pp. 

    3.    FAO/WHO (1980) Pesticide Residues in Food 1988, Evaluations 1988, 
          Part II - Toxicology, FAO Plant Production and Protection Paper 
          93/2, Rome, 1989. 

    4.    The Pesticide Manual, A World Compendium (9th edition 1991), 
          Worthing, C.R. and Hance, eds., British Crop Protection Council, 
          20 Bridport Road, Thornton Heath, CR4 7QG, United Kingdom. 

    5.    WHO (1991), Fourteenth Report of the WHO Expert Committee on 
          Vector Biology and Control, WHO Technical Report Series No. 813, 
          Safe Use of Pesticides;  Geneva, World Health Organization, 27 

                                            = = =        


See Also:
        d-Phenothrin (EHC 96, 1990)
        d-Phenothrin (UK PID)