IPCS INCHEM Home

    IPCS INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY
    Health and Safety Guide No. 28

    PHOSPHINE
    AND SELECTED METAL PHOSPHIDES
    HEALTH AND SAFETY GUIDE






    UNITED NATIONS ENVIRONMENT PROGRAMME

    INTERNATIONAL LABOUR ORGANISATION

    WORLD HEALTH ORGANIZATION




    WORLD HEALTH ORGANIZATION, GENEVA 1989

    This is a companion volume to Environmental Health Criteria 73:
    Phosphine and selected metal phosphides

    Published by the World Health Organization for the International
    Programme on Chemical Safety (a collaborative programme of the United
    Nations Environment Programme, the International Labour Organisation,
    and the World Health Organization)

    This report contains the collective views of an international group of
    experts and does not necessarily represent the decisions or the stated
    policy of the United Nations Environment Programme, the International
    Labour Organisation, or the World Health Organization

    ISBN 92 4 154349 3
    ISSN 0259-7268

    The World Health Organization welcomes requests for permission to
    reproduce or translate its publications, in part or in full. 
    Applications and enquiries should be addressed to the Office of
    Publications, World Health Organization, Geneva, Switzerland, which
    will be glad to provide the latest information on any changes made to
    the text, plans for new editions, and reprints and translations
    already available.

    (c) World Health Organization 1989

    Publications of the World Health Organization enjoy copyright
    protection in accordance with the provisions of Protocol 2 of the
    Universal Copyright Convention.  All rights reserved.

    The designations employed and the presentation of the material in this
    publication do not imply the expression of any opinion whatsoever on
    the part of the Secretariat of the World Health Organization
    concerning the legal status of any country, territory, city or area or
    of its authorities, or concerning the delimitation of its frontiers or
    boundaries.

    The mention of specific companies or of certain manufacturers'
    products does not imply that they are endorsed or recommended by the
    World Health Organization in preference to others of a similar nature
    that are not mentioned.  Errors and omissions excepted, the names of
    proprietary products are distinguished by initial capital letters.

    CONTENTS

    INTRODUCTION

    1. PRODUCT IDENTITY AND USES
         1.1. Identity
         1.2. Physical and chemical properties
         1.3. Analytical methods
         1.4. Production and uses

    2. SUMMARY AND EVALUATION
         2.1. Human exposure to phosphine and metal phosphides
         2.2. Fate in the environment
         2.3. Uptake, metabolism, and excretion
         2.4. Effects on organisms in the environment
         2.5. Effects on animals and human beings

    3. CONCLUSIONS AND RECOMMENDATIONS

    4. HUMAN HEALTH HAZARDS, PREVENTION AND PROTECTION, EMERGENCY
         ACTION
         4.1. Main human health hazards, prevention and protection,
               first aid
               4.1.1. Advice to physicians
               4.1.2. Health surveillance advice
         4.2. Explosion and fire hazards
         4.3. Storage
         4.4. Transport
         4.5. Spillage and disposal

    5. HAZARDS FOR THE ENVIRONMENT AND THEIR PREVENTION

    6. INTERNATIONAL CHEMICAL SAFETY CARD

    7. CURRENT REGULATIONS, GUIDELINES, AND STANDARDS
         7.1. Exposure limit values
         7.2. Specific restrictions
         7.3. Labelling, packaging, and transport

    BIBLIOGRAPHY

    

    INTRODUCTION

    The Environmental Health Criteria (EHC) documents produced by the
    International Programme on Chemical Safety include an assessment of
    the effects on the environment and on human health of exposure to a
    chemical or combination of chemicals, or physical or biological
    agents. They also provide guidelines for setting exposure limits.

    The purpose of a Health and Safety Guide is to facilitate the
    application of these guidelines in national chemical safety
    programmes. The first three sections of a Health and Safety Guide
    highlight the relevant technical information in the corresponding EHC.
    Section 4 includes advice on preventive and protective measures and
    emergency action; health workers should be thoroughly familiar with
    the medical information to ensure that they can act efficiently in an
    emergency. Within the Guide is an International Chemical Safety Card
    which should be readily available, and should be clearly explained, to
    all who could come into contact with the chemical. The section on
    regulatory information has been extracted from the legal file of the
    International Register of Potentially Toxic Chemicals (IRPTC) and from
    other United Nations sources.

    The target readership includes occupational health services, those in
    ministries, governmental agencies, industry, and trade unions who are
    involved in the safe use of chemicals and the avoidance of
    environmental health hazards, and those wanting more information on
    this topic. An attempt has been made to use only terms that will be
    familiar to the intended user. However, sections 1 and 2 inevitably
    contain some technical terms. A bibliography has been included for
    readers who require further background information.

    Revision of the information in this Guide will take place in due
    course, and the eventual aim is to use standardized terminology.
    Comments on any difficulties encountered in using the Guide would be
    very helpful and should be addressed to:

    The Manager

    International Programme on Chemical Safety
    Division of Environmental Health
    World Health Organization
    1211 Geneva 27
    Switzerland

    THE INFORMATION IN THIS GUIDE SHOULD BE CONSIDERED AS A STARTING POINT
    TO A COMPREHENSIVE HEALTH AND SAFETY PROGRAMME

    1.  PRODUCT IDENTITY AND USES

    1.1  Identity

     Phosphine

    Chemical formula:        PH3

    Structural formula:      H
                             '
                             P - H
                             '
                             H

    Common synonyms:         hydrogen phosphide, phosphorus trihydride,
                             phosphoretted hydrogen, phosphane

    CAS registry number:     7803-51-2

    RTECS registry
    number:                  SY7525000

    United Nations
    number:                  UN 2199

    Conversion factor:       20C, 1 ppm = 1.41 mg/m3 and
                             1 mg/m3 = 0.71 ppm, approximately.

     Metal phosphides

    Name:               trizinc         aluminium      trimagnesium
                        diphosphide     phosphide      diphosphide

    Chemical formula:   Zn3P2           AlP            Mg3P2

    Structural          Zn = P-Zn-P     Al equiv. P    Mg = P-Mg-P
    formula:            = Zn                           = Mg

    Common synonyms:    zinc            phosphide      magnesium
                                                       phosphide

    CAS registry        1314-84-7       20859-73-8     12057-74-8
    number:

    RTECS number:       ZH4900000       BD1400000      OM4200000

    United Nations      1714            1397/3048      2011
    number:

     Trade names and presentations

                             Registered Trade      Presentation
                             Name

    Aluminium phosphide      Alutal
                             Celphide              Tablets
                             Celphine              Tablets
                             Celphos               Tablets
                             Delicia Gastoxin
                             Detia Gas-Ex-B        Bags
                             Detia Gas-Ex-P        Pellets
                             Detia Gas-Ex-T        Tablets
                             "L" fume              Tablets
                             Phosfume              Pellets & tablets
                             Phostek               Pellets & tablets
                             Phostoxin             Pellets, tablets,
                                                   "Prepacs", rounds &
                                                   strips
                             Quickfos              Pellets & tablets
                             Zedesa                Bags, pellets &
                                                   tablets
    Magnesium phosphide      Detiaphos             Pellets
                             Mag-disc              Plates
                             Magtoxin              Pellets, tablets &
                                                   rounds

    1.2  Physical and Chemical Properties

    Phosphine is a colourless gas at room temperature and normal
    atmospheric pressure. It is odourless when pure at concentrations up
    to 282 mg/m3 (200 ppm), a highly toxic level. The "garlicky" odour
    of technical phosphine depends on the presence of odoriferous
    impurities and is usually detectable at concentrations in the range
    0.14-7 mg/m3. The autoignition temperature of pure phosphine is
    38C, but the presence of impurities, particularly diphosphine
    (PH2-PH2), often causes the technical product to ignite spontaneously
    at room temperature and it forms explosive mixtures with air at
    concentrations greater than 1.8%. Oxidation of phosphine yields water
    and phosphorus oxides or oxyacids.

    Phosphine is sparingly soluble in water (about 2.5% v/v at about 20C)
    but is soluble at 2.5-15% v/v in most organic solvents at ambient
    temperatures. It has an intense ultraviolet absorption in the
    185-250 nm region. Phosphine is corrosive to metals, particularly
    copper and copper alloys. Electrical and other equipment may be
    severely damaged during fumigation. Contact with hot surfaces in the
    absence of oxygen causes phosphine to break down to phosphorus and
    hydrogen.

    Trimagnesium diphosphide and aluminium phosphide hydrolyse readily in
    water to yield phosphine:

    2AlP  + 6H2O = 2PH3 + 2Al(OH)3

    Mg3P2 + 6H2O = 2PH3 + 3Mg(OH)2

    Zinc phosphide hydrolyses in acid environments:

    Zn3P2 + 6H + = 2PH3 + 3Zn+ +

    Technical phosphine may contain up to 5% diphosphine and other
    impurities such as methane, methyl phosphine, and arsine. For use in
    the electronics industry, phosphine may be compressed as a mixture
    with nitrogen. Phosphine released from fumigant preparations may
    contain ammonia.

    Zinc phosphide in bulk usually has a purity of 80%, the remainder
    consisting mainly of zinc oxide, metallic zinc, and red phosphorus.
    Pastes for incorporation into baits for use as a rodenticide usually
    contain 2.5% or 5% active ingredient. Commercial preparations for
    fumigation usually contain about 57% of aluminium phosphide or 34% of
    trimagnesium diphosphide as active ingredient.

    1.3  Analytical Methods

    Gas chromatography is the most sensitive method for the determination
    of the phosphine content of air samples. Usually, samples are desorbed
    from a solid absorbent coated with mercury (II) cyanide, although
    samples taken in syringes, gas bags, or tonometers can be used. The
    sensitivity depends on the type of detector.

    Phosphine levels in air may be determined by trapping phosphine by
    absorption or reaction, and subsequently analysing the desorbed or
    reacted sample with mercury (II) chloride, followed by the addition of
    potassium iodide and then excess standard iodine solution.
    Back-titration of the excess iodine with thiosulfate is used to
    quantify the phosphine.

    Alternatively, mercury (II) cyanide on silica gel collects phosphine
    quantitatively and holds 80% of the phosphine during storage for 2
    weeks. The phosphine is released for gas chromatographic analysis by
    treatment with alkaline sodium borohydride solution or is oxidized
    (using a hot acid permanganate solution) to phosphate, which is
    measured using the phosphomolybdate colorimetric technique.

    Liquid impingers/bubblers containing a variety of solutions can be
    used to collect and react phosphine for quantification by
    colorimetry/spectrophotometry, by conductance, or by potentiometric
    titration. Classical colorimetric techniques are the development of

    the red-orange complex with silver diethyldithiocarbamate, which can
    be measured at 465 nm, or the oxidation by permanganate to phosphate
    which is then reacted with a solution of ammonium molybdate in
    concentrated sulfuric acid, extracted with toluene-isobutanol, reduced
    with tin (II) chloride, and measured as the phosphomolybdate complex
    at 625 nm. The first method suffers from arsine interference and the
    second also measures any phosphorus species that are oxidized to
    phosphate by oxalic acid/permanganate treatment.

    1.4  Production and Uses

    Phosphine is manufactured by the hydrolysis of metal phosphides, by
    the electrolysis of phosphorus in the presence of hydrogen, or by the
    phosphorus-steam reaction. It is produced incidentally by the
    hydrolysis of impurities in calcium carbide, ferrosilicon, and
    spheroidal graphite iron. Metal phosphides are produced by the
    reduction of phosphates, by a direct reaction between the metal and
    phosphorus vapour or amorphous phosphorus, or by an exchange reaction
    between the metal and another metal phosphide.

    Phosphine is used in the synthesis of organophosphines and organic
    phosphonium derivatives and as a dopant in the manufacture of
    semiconductors. Aluminium or magnesium phosphide are used as
    formulations prepared for fumigation in pest control, and zinc
    phosphide, as a powder or paste, is used as a rodenticide.

    2. SUMMARY AND EVALUATION

    2.1  Human Exposure to Phosphine and Metal Phosphides

    Exposure of the skin, the eyes, or the respiratory tract may occur.
    There may be mild irritation of the mucous membranes, but significant
    absorption occurs only via the lungs. Metal phosphides and their
    preparations may be ingested accidentally or with suicidal intent. In
    occupational situations where phosphine is produced deliberately or
    known to be produced, safe working practices can reduce exposure to
    low levels. In many countries, fumigation and re-entry procedures are
    regulated to prevent exposure. Occupational exposure to toxic levels
    has occurred in circumstances where phosphine is produced
    incidentally. Members of the public have been exposed as a result of
    leaks from fumigated warehouses and from the holds of ships or barges.
    There may be exposure from the consumption of fumigated foodstuffs.

    2.2  Fate in the Environment

    Phosphine released into the atmosphere reacts principally with the HO*
    radical to form HOP*. The eventual products will be water and
    phosphorus oxyacids. Phosphine is also removed from air by soils and
    oxidized to orthophosphate. Zinc phosphide disappears from soils of
    50% or more water content in less than 5 weeks, and the majority is
    recoverable as orthophosphate.

    2.3  Uptake, Metabolism, and Excretion

    Phosphine is absorbed readily through the lungs and produces early
    symptoms in the brain and liver, suggesting that it is rapidly
    distributed at least to these organs. After peak exposure, phosphine
    is excreted in the expired air and some is oxidized to phosphite and
    hypophosphite ions, which are excreted in the urine. Metal phosphides
    may hydrolyse to produce phosphine, which may be absorbed through the
    intestine after ingestion. Some zinc phosphide has been shown to reach
    the liver and kidneys intact after ingestion and to hydrolyse slowly
    in the tissues to phosphine and zinc salts. Hydrolysis of metal
    phosphides on the skin could lead to the evolution of gaseous
    phosphine, which could then be absorbed by inhalation. Little
    percutaneous absorption of metal phosphides occurs.

    2.4  Effects on Organisms in the Environment

    Phosphine is not normally present in the environment and any that is
    released into it will be rapidly diluted and subsequently oxidized so
    that its effects are minimal. Phosphine and metal phosphides are
    deliberately released into confined locations for the purpose of
    eliminating certain pests. Phosphine has been demonstrated to be

    effective against many species of arthropod, though the susceptibility
    of the different developmental stages may vary. In general, larvae are
    more susceptible than adults; pupae tend to be less susceptible and
    eggs least susceptible. Diapausing larvae may be relatively resistant.
    Zinc phosphide baits can be laid for rodent pests and the effect on
    non-target species can be minimized by applying a knowledge of the
    habits and runs, or by using magnesium or aluminium phosphide
    preparations in the burrows of target pest species. Animals killed by
    metal phosphides have been demonstrated to be nontoxic to carrion
    eaters.

    2.5  Effects on Animals and Human Beings

    The 4-hour LC50 for phosphine in rats is 15 mg/m3. Quoted oral LD50
    values for zinc phosphide in the rat are in the range of 30-40 mg/kg
    body weight.

    Acute exposure to phosphine produces similar effects in man and
    animals. Concentrations approaching 3000 mg/m (2000 ppm) are rapidly
    fatal. Concentrations of about 700 mg/m3 (500 ppm) cause death in
    0.5-1 hour. Concentrations around 200 mg/m3 (150 ppm) will produce
    serious effects after 0.5-1 hour; concentrations around 10 mg/m3 have
    no serious effects with the same exposure duration. The predominant
    pathological feature in acute fatal cases is pulmonary oedema. Severe
    non-lethal cases complain of pain and tightness in the chest.
    Neurological abnormalities include headache, vertigo, tremors, and
    unsteady gait, and may progress to convulsions, coma, and death; they
    may mimic alcoholic intoxication. Gastrointestinal symptoms include
    loss of appetite, thirst, nausea, vomiting, diarrhoea, epigastric
    pain, and jaundice. Other effects described include thrombocytopenic
    purpura and hypotension.

    While phosphine itself is not cumulative, its effects appear to be, so
    that the lethal dose of inhaled phosphine after several days'
    treatment with short, sublethal exposures is lower than in animals
    without pretreatment. Deaths have occurred in man as a result of
    repeated daily exposures to concentrations well below acutely
    injurious concentrations.

    The effects of suicidally ingested zinc phosphide are well known. In
    most cases, the ingestion of more than 20 g is fatal: most people who
    ingest less than 20 g survive. Clinical features include metabolic
    disturbances (metabolic acidosis, hypocalcaemic tetany), congestion in
    many organs, haemorrhagic changes in the intestines and serous
    membranes, and clinical signs and pathological features of liver and
    kidney failure.

    There have been no long-term studies on the effects of phosphine or
    metal phosphides on animals or man and there are no data relating to
    mutagenicity, teratogenicity, or carcinogenicity.

    3. CONCLUSIONS AND RECOMMENDATIONS

    Phosphine is a highly toxic gas and considerable care needs to be
    taken during production, storage, and use, and where it may arise in
    the course of other procedures. However, it presents no hazard to the
    general population and accidental emissions into the environment are
    most unlikely to cause persistent or high concentrations, or to lead
    to accumulation. Apart from its use in chemical synthesis and
    electronics, phosphine is used chiefly for its toxic effects. Its
    chemical simplicity and rapid dispersion and conversion into simple
    inorganic molecules of low toxicity make it very suitable for this
    purpose.

    Metal phosphides, if carefully used, present little risk to those who
    use them, or to the general population, or to important non-target
    species in the environment. Administrative controls are necessary to
    prevent easy access by children, persons with diminished
    responsibility, or those with suicidal intent.

    4.  HUMAN HEALTH HAZARDS, PREVENTION AND PROTECTION, EMERGENCY ACTION

    4.1  Main Human Health Hazards, Prevention and Protection, First Aid

    The main hazard to man is the possibility of unrecognized occupational
    exposure to phosphine causing acute poisoning. Neither the smell nor
    sensory irritation can be relied upon for warning of toxic
    concentrations, especially in the presence of other fumes, gases, or
    vapours. Another important hazard is the possibility of members of the
    public being affected by phosphine leaking from fumigated warehouses
    or cargoes, or evolving spontaneously from cargoes of ferrosilicon. In
    agricultural communities, children may be at risk from the accidental
    consumption of bait poisoned with zinc phosphide.

    The human health hazards are listed on the International Chemical
    Safety Card, on pages 22-26, together with preventive and protective
    measures and first aid recommendations.

    4.1.1  Advice to physicians

    In the case of exposure to phosphine, rapid recovery will usually
    occur when the patient is moved to fresh air. No specific antidote is
    known. Hypotension has been described following exposure, but signs of
    peripheral vasoconstriction are not normally present and plasma
    expanders are probably not required. Tests may indicate disordered
    liver function. If supportive treatment is successful, full recovery
    usually follows. After recovery, a period of rest and avoidance of
    alcohol is advisable until the affected organs have fully recovered.

    After severe exposure to the vapour, the risk of delayed pulmonary
    oedema may be sufficient to require admission of the patient to
    hospital for observation for 24-48 h. An initial chest X-ray will be
    useful for later assessment of the development of pulmonary oedema.
    Bronchodilators by nebulizer or metered dose aerosol may be given to
    reduce bronchospasm and dyspnoea. Where there are immediate
    respiratory symptoms suggestive of lower airway exposure, it may be
    beneficial to administer steroids to minimize chemical pneumonitis and
    scarring. Steroids may administered by intravenous injection of
    methylprednisolone in doses up to 30 mg/kg body weight initially, with
    subsequent smaller doses, or by use of steroids in metered-dose
    aerosol form at several times the normal maintenance dosage.
    Prophylactic antibiotics are generally indicated in all but mild
    cases, since secondary bacterial infection of the airways often
    occurs.

    If pulmonary oedema develops, the patient should be nursed with the
    trunk upright and oxygen should be administered. Diuretics, morphine,
    and theophylline derivatives are of little benefit, since the oedema
    is the result of an exudate rather than a transudate arising from
    raised pulmonary capillary pressure. If further measures are
    necessary, intermittent positive pressure ventilation combined with
    bronchial toilet and suction are the important elements of treatment.

    In the event of ingestion of metal phosphides, tracheal intubation and
    gastric lavage with sodium bicarbonate solution may remove some of the
    material and may reduce the amount of phosphine evolved. Potassium
    permanganate has been used in an attempt to oxidize the phosphide. On
    a theoretical basis, the administration of activated charcoal may
    adsorb some of the evolved phosphine and there is a possibility that
    the administration of medicinal paraffin may reduce the hydrolysis and
    absorption of the phosphide itself.

    Otherwise, treatment should be symptomatic and supportive with
    particular attention to liver and kidney function.

    4.1.2  Health surveillance advice

    It is advisable for persons with pre-existing gastrointestinal or
    liver disease to be excluded from work with phosphine. Wherever
    measured exposures approach the occupational exposure limit or where
    exposure levels require the use of personal respiratory protection
    equipment, it is wise to measure pulmonary and liver function
    routinely.

    4.2  Explosion and Fire Hazards

    Phosphine (unless of very high purity) ignites spontaneously in air at
    ambient temperatures at concentrations above 1.8%. Where emissions
    exceed this concentration, controlled combustion is the best way of
    preventing accidental fires and explosion. Such concentrations are not
    normally reached during fumigation. Fire-fighters should wear
    compressed-air breathing apparatus.

    4.3  Storage

    Phosphine admixed with inert gases in cylinders should be stored in
    accordance with the usual practices for compressed gases in a cool,
    dry, well ventilated place. For industrial purposes, phosphine may be
    stored in a gas-holder, suitably constructed to resist corrosion, from
    which air can be excluded. Large quantities of phosphine can
    constitute a major hazard and appropriate installations are required
    for the control of such hazards. Metal phosphides should be stored in
    sealed, polyethylene-lined drums in a well ventilated, dry warehouse.
    Drums should be carefully handled to avoid puncturing. Formulated
    commercial preparations of metal phosphides should be stored dry in a
    locked cupboard out of the reach of children.

    4.4  Transport

    In case of accident during transport by road, stop the engine and
    remain up-wind. Do not apply water to spilled metal phosphides. If a
    gas cloud drifts towards an inhabited area, warn the inhabitants and
    evacuate areas close to the spillage, if this can be done without
    risking exposure.

    4.5  Spillage and Disposal

    Surplus gas or leakages of gas from cylinders can be vented slowly to
    air in a safe open area, or the gas can be burnt off through a
    suitable burner in a fume cupboard. It may be spontaneously flammable
    and jets from leaking valves may ignite. Large spillages of magnesium
    or aluminum phosphides or preparations formulated from them should be
    kept dry and shovelled into containers that can be sealed by persons
    equipped with respiratory protective equipment effective against
    phosphine. The containers should be removed to a secure site where
    they can be placed open in a deep pit, kept moist, and allowed to
    hydrolyse slowly until all the phosphine has evolved. Residues may
    then be disposed of by deep burial in an approved landfill. The
    contaminated area should be washed down with copious amounts of water.
    Small spills may be allowed to hydrolyse  in situ if the public and
    domestic animals can be kept away.

    Spillages of zinc phosphide should be collected in sealable containers
    by persons wearing respiratory protection and the material should be
    disposed of by high-temperature incineration, or made chemically inert
    in accordance with advice from an expert.

    Combustible packages can be incinerated at high temperatures or
    disposed of in deep landfill.

    5. HAZARDS FOR THE ENVIRONMENT AND THEIR PREVENTION

    Phosphine is used deliberately in the environment to eliminate pests,
    but only where the environment has been extensively modified by
    industrial or agricultural activities. Its use does not impose any
    recognized environmental hazard apart from this.

    6. INTERNATIONAL CHEMICAL SAFETY CARD

     This card should be easily available to all health workers
     concerned with, and users of, phosphine and metal phosphides. It
     should be displayed at, or near, entrances to areas where there is
     potential exposure to phosphine or phosphides, and on processing
     equipment and containers. The card should be translated into the
     appropriate language(s). All persons potentially exposed to the
     chemical should also have the instructions on the chemical safety
     card clearly explained.

     Space is available on the card for insertion of the National
     Occupational Exposure Limit, the address and telephone number of
     the National Poison Control Centre, and for local trade names.


        INTERNATIONAL CHEMICAL SAFETY CARD
                                                                                                                                                

    PHOSPHINE
    (Hydrogen phosphide, phosphorus trihydride, phosphoretted hydrogen, phosphane)
    (CAS Registry No. 7803-51-2)
                                                                                                                                                

    PHYSICAL PROPERTIES                                                           OTHER CHARACTERISTICS
                                                                                                                                                

    Relative molecular mass                        34                             A colourless gas at ambient temperature and
    Melting point                                  -133.5C                       pressure; it is odourless in the pure state but
    Boiling point                                  -87.4C                        technical phosphine characteristically has a
    Relative vapour density                        1.17                           "fishy" or "garlicky" odour due to impurities
    Spontaneous ignition temperature               38Ca
    Lower explosive limit                          1.8%
                 
    a   Varies with the presence of impurities.
                                                                                                                                                

    TRIZINC DIPHOSPHIDE
    (Zinc phosphide)
    (CAS Registry No. 1314-84-7)
                                                                                                                                                

    PHYSICAL PROPERTIES                                                           OTHER CHARACTERISTICS
                                                                                                                                                

    Relative molecular mass                        258.1                          A grey solid
    Melting point                                  sublimes
    Density (13C)                                 4.55
                                                                                                                                                

    INTERNATIONAL CHEMICAL SAFETY CARD (cont'd).

    ALUMINIUM PHOSPHIDE
    (CAS Registry No. 20859-73-8)
                                                                                                                                                

    PHYSICAL PROPERTIES                                                           OTHER CHARACTERISTICS
                                                                                                                                                

    Relative molecular mass                        57.96                          A grey/yellow solid
    Melting point                                  > 1350C
    Density (25C)                                 2.85
                                                                                                                                                

    TRIMAGNESIUM DIPHOSPHIDE
    (Magnesium phosphide)
    (CAS Registry No. 12057-74-8)
                                                                                                                                                

    PHYSICAL PROPERTIES                                                           OTHER CHARACTERISTICS
                                                                                                                                                

    Relative molecular mass                        134.87                         A grey solid
    Melting point                                  > 750C
    Density (25C)                                 2.1
                                                                                                                                                

    INTERNATIONAL CHEMICAL SAFETY CARD (cont'd).
                                                                                                                                                

    HAZARDS/SYMPTOMS                           PREVENTION AND PROTECTION                 FIRST AID
                                                                                                                                                

    PHOSPHINE GAS FUMES

     SINGLE EXPOSURE

    SKIN & EYES: No local effects or           Full-face mask protects eyes              Not required
    significant absorption

    INHALATION: Irritation of respiratory      Avoid exposure by enclosure,              Move patient to fresh air and keep
    tract; effects on the central nervous      exhaust ventilation, or suitable          him quiet; if breathing has stopped,
    system include ataxia which may mimic      respiratory protective equipment;         apply artificial respiration; if
    drunkenness and hypotension; nausea        odour may not warn of toxic               pulse is feeble or there is clouding
    and upper gastrointestinal symptoms        concentrations                            of consciousness, lie patient down
    may occur; eventually, unconsciousness,                                              with the feet raised
    respiratory depression, and death
    may occur

    INGESTION: Not possible

     REPEATED EXPOSURE

    There is some evidence that effects may summate with the residual effects of previous exposure

    INHALATION: There is a possibility         As for single exposure
    of upper gastrointestinal symptoms
    and headache

    SKIN & EYES: No recognized chronic
    effects
                                                                                                                                                

    INTERNATIONAL CHEMICAL SAFETY CARD (cont'd).
                                                                                                                                                

    HAZARDS/SYMPTOMS                           PREVENTION AND PROTECTION                 FIRST AID
                                                                                                                                                

    METAL PHOSPHIDES

     SINGLE EXPOSURE

    SKIN: No evidence of irritation,           Avoid exposure: handle pellets,           Work in the open or in a well-ventilated
    direct absorption; hydrolysis in           disks, etc., using gloves or the          place; brush off any dry material and
    atmospheric moisture or perspiration       wrapper; dry exposed skin and wear        then wash or shower thoroughly using soap
    may yield gaseous phosphine, which         gloves before mixing powdered             if available; if there are signs of phosphine
    could be inhaled                           material; wash thoroughly in a            inhalation, see International Chemical Safety
                                               well-ventilated place after               Card for phosphine
                                               handling

    EYES: Mechanical and chemical              Avoid exposure; keep contaminated         Rinse thoroughly with a gentle flow of water for
    irritation                                 gloves and hands away from face;          at least 15 minutes
                                               handle powder so as to minimize
                                               dust; wear goggles

    INHALATION: Irritation of respiratory      Handle powdered material so as to         See International Chemical Safety Card for
    tract both directly and by the             minimize dust; ensure good local          phosphine
    evolution of phosphine; possible           and general ventilation.
    systemic effects from phosphine            Respiratory protective equipment,
    absorption (see International Chemical     if required, should be effective
    Safety Card for phosphine)                 against both phosphide dusts and
                                               gaseous phosphine
                                                                                                                                                

    INTERNATIONAL CHEMICAL SAFETY CARD (cont'd).
                                                                                                                                                

    HAZARDS/SYMPTOMS                           PREVENTION AND PROTECTION                 FIRST AID
                                                                                                                                                

    INGESTION: Nausea, abdominal               Keep all preparations locked up           Induce vomiting in conscious
    pain, and vomiting; circulatory            and out of reach of children; do          patients who have not vomited; give
    collapse, altered consciousness,           not eat or smoke while using              activated charcoal as a suspension
    coma, convulsions; signs of gross          preparations and wash hands after         in water by mouth, repeat after vomiting,
    liver and kidney disturbance               use                                       and obtain medical attention

     REPEATED EXPOSURE

    There is some evidence that effects will summate with the residual effects of previous exposures
                                                                                                                                                

    
    7. CURRENT REGULATIONS, GUIDELINES, AND STANDARDS

    The information in this section has been extracted from the
    International Register of Potentially Toxic Chemicals (IRPTC) legal
    file. The reader should be aware that regulatory decisions about
    chemicals taken in a certain country can only be understood in the
    framework of legislation in that country.a

    A full reference to the original national document from which the
    information was extracted can be obtained from IRPTC. When no
    effective date appears on the IRPTC legal file, the year of the
    reference from which the data are taken is indicated by (r).

    7.1  Exposure Limit Values

    Some exposure limit values are given in the following table.

    7.2  Specific Restrictions

    There are restrictions on the use of phosphine as a pesticide in
    Brazil, Czechoslovakia, the Federal Republic of Germany, Sweden, and
    the USSR.

    In Czechoslovakia and Japan, phosphine and phosphides are classified
    as dangerous poisonous substances.

    In the Federal Republic of Germany, the level of phosphine in air
    emissions may not exceed 1 mg/m3 at a mass flow rate of 10 g/h.
    Phosphine is classified as harmful in water and appropriate measures
    are required to protect water supplies.

    In the European Economic Community, phosphine is listed as a dangerous
    substance in quantities greater than 100 kg.

    In the USA, commercial chemical products containing phosphine are
    classified as acute hazardous wastes, and solid waste (except
    domestic) containing phosphine is classified as hazardous waste.

    7.3  Labelling, Packaging, and Transport

    The United Nations classifies phosphine as a hazardous gas
    (compressed) with the subsidiary risks of a flammable liquid and a
    poisonous substance.

                 

    a  The regulations and guidelines of all countries are subject to
       change and should always be verified with the appropriate regulatory
       authorities before application.


        EXPOSURE LIMIT VALUES
                                                                                                                                                

    Medium     Specification     Country/           Exposure limit description                       Value                Effective
                                 organization                                                                             date
                                                                                                                                                

    AIR        Occupational      Australia          Threshold limit value (TLV)                                           1985 (r)
                                                    - Time-weighted average (TWA)                    0.4 mg/m3

                                 Belgium            Threshold limit value                                                 1987 (r)
                                                    - Time-weighted average                          0.4 mg/m3
                                                    - Short-term exposure limit (STEL)               1 mg/m3

                                 Bulgaria           Maximum permissible concentration (MPC)                               1985
                                                    - Time-weighted average                          0.1 mg/m3

                                 Canada             Threshold limit value                                                 1985 (r)
                                                    - Time-weighted average                          0.4 mg/m3
                                                    - Short-term exposure limit                      1 mg/m3

                                 Czechoslovakia     Maximum allowable concentration (MAC)                                 1985
                                                    - Time-weighted average                          0.1 mg/m3
                                                    - Ceiling value (CLV)                            0.2 mg/m3

                                 Finland            Maximum permissible concentration                                     1985 (r)
                                                    - Time-weighted average                          0.1 mg/m3

    AIR        Occupational      German             Maximum allowable concentration                                       1985 (r)
                                 Democratic         - Time-weighted average                          0.1 mg/m3
                                 Republic           - Short-term exposure limit                      0.3 mg/m3
                                                                                                                                                

    EXPOSURE LIMIT VALUES (cont'd).
                                                                                                                                                

    Medium     Specification     Country/           Exposure limit description                       Value                Effective
                                 organization                                                                             date
                                                                                                                                                

                                 Germany,           Maximum work-site concentration (MAK)                                 1987 (r)
                                 Federal            - Time-weighted average                          0.15 mg/m3
                                 Republic of        - Short-term exposure limit                      0.3 mg/m3
                                                    (5 minutes, 8 /shift)

                                 Italy              Threshold limit value                                                 1985 (r)
                                                    - Time-weighted average                          0.4 mg/m3

                                 Netherlands        Maximum limit (MXL)                                                   1987 (r)
                                                    - Time-weighted average                          0.4 mg/m3
                                                    - Short-term exposure limit                      1.5 mg/m3

                                 Poland             Maximum permissible concentration                                     1985 (r)
                                                    - Ceiling value                                  0.1 mg/m3

                                 Romania            Maximum permissible concentration                                     1985 (r)
                                                    - Time-weighted average                          0.2 mg/m3
                                                    - Ceiling value                                  0.5 mg/m3

                                 Sweden             Hygiene limit value (HLV)                                             1988
                                                    - Time-weighted average                          0.4 mg/m3
                                                    - Short-term exposure limit                      1.4 mg/m3
                                                    (15-minutes time-weighted average)

                                 Switzerland        Maximum work-site concentration                                       1987 (r)
                                                    - Time-weighted average                          0.15 mg/m3
                                                                                                                                                

    EXPOSURE LIMIT VALUES (cont'd).
                                                                                                                                                

    Medium     Specification     Country/           Exposure limit description                       Value                Effective
                                 organization                                                                             date
                                                                                                                                                

                                 United             Recommended exposure control limit (RECL)                             1987 (r)
                                 Kingdom            - Time-weighted average                          0.4 mg/m3
                                                    - Short-term exposure limit                      1 mg/m3
                                                    (10-minutes time-weighted average)

                                 USA (ACGIH)        Threshold limit value                                                 1987 (r)
                                                    - Time-weighted average                          0.4 mg/m3
                                                    - Short-term exposure limit                      1 mg/m3

                                 USA (OSHA)         Permissible exposure limit (PEL)                                      1987 (r)
                                                    - Time-weighted average                          0.4 mg/m3

                                 USSR               Maximum allowable concentration                                       1977
                                                    - Ceiling value                                  0.1 mg/m3

                                 Yugoslavia         Maximum allowable concentration                                       1985 (r)
                                                    - Time-weighted average                          0.1 mg/m3

    AIR        Ambient           USSR               Maximum allowable concentration                                       1984
                                                    - Daily average                                  0.001 mg/m3
                                                    - Once daily                                     0.01 mg/m3

    WATER      Surface           USSR               Maximum allowable concentration                  0.1 mg/litre         1985 (r)
                                                    (surface water for fishing)
                                                                                                                                                

    EXPOSURE LIMIT VALUES (cont'd).
                                                                                                                                                

    Medium     Specification     Country/           Exposure limit description                       Value                Effective
                                 organization                                                                             date
                                                                                                                                                

    FOOD                         FAO/WHO            Maximum residue limit                                                 1982 (r)
                                                    - Flour, milled cereal products,
                                                    breakfast cereals, dried vegetables,
                                                    spices, nuts, peanuts, dried fruit,
                                                    cocoa beans, other dried foods                   0.01 mg/kg

                                 EEC                Maximum residue limit                                                 1988
                                                    - Cereals (general)                              0.1 mg/kg

                                 Brazil             Acceptable limit (AL)                                                 1985 (r)
                                                    (Specified plants)                               0.01-0.1 mg/kg

                                 Czechoslovakia     Maximum residue limit                            0.01-0.1 mg/kg       1978

                                 Germany,           Maximum residue limit                                                 1984
                                 Federal            - Specified plant products                       0.01-0.1 mg/kg
                                 Republic of        - Other plant products                           0.01 mg/kg
                                                    - Tobacco                                        0.01 mg/kg

                                 India              Maximum tolerable concentration (MTC)                                 1976
                                                    - Specified food products                        0.01-0.05 mg/kg

                                 USSR               Maximum residue limit                                                 1984
                                                    - Food exported and imported                     0.01-0.1 mg/kg
                                                                                                                                                

    EXPOSURE LIMIT VALUES (cont'd).
                                                                                                                                                

    Medium     Specification     Country/           Exposure limit description                       Value                Effective
                                 organization                                                                             date
                                                                                                                                                

                                 USA                Acceptable residue limit (ARL)                                        1983 (r)
                                                    - Raw agricultural products: phosphine
                                                    resulting from use of zinc phosphide             0.01-0.1 mg/kg
                                                    - Raw agricultural products: phosphine
                                                    resulting from use of aluminum or
                                                    magnesium phosphides as preharvest
                                                    pest treatment                                   0.1 mg/kg
                                                    - Processed foods: phosphine resulting                                1985 (r)
                                                    from fumigation by magnesium or
                                                    aluminum phosphides                              0.01 mg/kg
                                                                                                                                                
    
    BIBLIOGRAPHY

    ACGIH (1986)  Documentation of the threshold limit values and
     biological exposure indices. Cincinnati, American Conference of
    Governmental Industrial Hygienists.

    CLAYTON, G.D. & CLAYTON, F.E. (1981)  Patty's industrial hygiene and
     toxicology. Vol. 2.4. New York, Wiley - Interscience, John Wiley &
    Sons.

    DUTCH ASSOCIATION OF SAFETY EXPERTS (1980)  Handling chemicals
     safely. 2nd ed. Dutch Chemical Industry Association, Dutch Safety
    Institute.

    GOSSELIN, R.E., ET AL. (1976)  Clinical toxicology of commercial
     products. 4th ed. Baltimore, Maryland, Williams and Wilkins Company.

    IRPTC (1988)  Data profile (legal file, waste disposal file,
     treatment of poisoning file), Geneva, International Register of
    Potentially Toxic Chemicals.

    SAX, N.I. (1984)  Dangerous properties of industrial materials. New
    York, Van Nostrand Reinhold Company.

    US NIOSH (1976)  A guide to industrial respiratory protection.
    Cincinnati, Ohio, US National Institute for Occupational Safety and
    Health.

    US NIOSH/OSHA (1985)  Pocket guide to chemical hazards. Washington,
    DC, US National Institute for Occupational Safety and Health,
    Occupational Safety and Health Association (Publication
    No. 85.114).

    US NIOSH/OSHA (1981)  Occupational health guidelines for chemical
     hazards. 3 vol. Washington, DC, US National Institute for
    Occupational Safety and Health, Occupational Safety and Health
    Association (Publication No. 01.123).

    WHO (1988)  Phosphine and selected metal phosphides. Geneva, World
    Health Organization (Environmental Health Criteria 73).
    


    See Also:
       Toxicological Abbreviations
       Phosphine (ICSC)
       Phosphine (PDS)
       Phosphine (PIM 865)