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    IPCS INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY
    Health and Safety Guide No. 37

    AMMONIA
    HEALTH AND SAFETY GUIDE






    UNITED NATIONS ENVIRONMENT PROGRAMME

    INTERNATIONAL LABOUR ORGANISATION

    WORLD HEALTH ORGANIZATION




    WORLD HEALTH ORGANIZATION, GENEVA 1990

    This is a companion volume to Environmental Health Criteria 37:
    Ammonia

    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

    WHO Library Cataloguing in Publication Data

    Ammonia: Health and safety guide.

         (Health and safety guide ; no. 37)

         1.Ammonia - standards  I.Series

         ISBN 92 4 151037 4          (NLM Classification: QV 233)
         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 1990

    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
               1.3.1. Air
               1.3.2. Water
         1.4. Production and uses

    2. SUMMARY AND EVALUATION

         2.1. Exposure to ammonia
         2.2. Fate
         2.3. Uptake, metabolism, and excretion
         2.4. Effects on animals and human beings
         2.5. Effects on organisms in the environment

    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
               4.5.1. Spillage
               4.5.2. Disposal

    5. HAZARDS FOR THE ENVIRONMENT AND THEIR PREVENTION

    6. CURRENT REGULATIONS, GUIDELINES, AND STANDARDS

         6.1. Exposure limit values
         6.2. Specific restrictions
         6.3. Labelling, packaging, and transport
         6.4. Waste disposal

    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. 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

    Chemical formula:        NH3

    Chemical structure:          H
                                 '
                             H - N
                                 '
                                 H

    Common synonyms:         none

    CAS registry number:     7664-41-7

    RTECS number:            BO 0875000

    UN number:               1005

    Conversion factor:       1 ppm = 0.70 mg/m3; 1 mg/m3 = 1.42 ppm
                             approximately, depending on temperature
                             and pressure

    1.2  Physical and Chemical Properties

    Ammonia is a colourless acrid-smelling gas at room temperature and
    normal atmospheric pressure. Most people can identify its odour at
    35 mg/m3 in air. It can be stored and transported as a liquid at a
    pressure of 10 atmospheres at 25C. Spilled liquid ammonia boils
    immediately, cooling its surroundings as it vaporizes. The gas
    dissolves readily in water; in solution it forms, and is in
    equilibrium with, ammonium ions (NH4+). Ammonia solutions are
    alkaline and react with acids to form ammonium salts.

    Gaseous ammonia is usually very pure and the purity of solutions
    depends on the purity of the water used, e.g., chlorinated water may
    give rise to chloramines and nitrogen trichloride.

    1.3  Analytical Methods

    1.3.1  Air

    In the alkalimetric method, air is drawn through sulfuric acid until
    the bromophenol indicator changes colour. The volume of air causing
    the change is inversely proportional to the ammonia concentration. The
    method is subject to interference by acidic or alkaline contaminants.
    With the Nesslerization technique, the ammonia/ammonium is collected
    in dilute sulfuric or boric acid and reacted with alkaline mercuric
    and potassium iodide solution; distillation can precede analysis.

    Absorbance at 440 nm is compared with a standard curve. Interference
    can be caused by amines, cyanates, alcohols, aldehydes, ketones,
    colour, turbidity, and residual chlorine. Ammonia can be measured
    using the indophenol reaction in which ammonia in solution is reacted
    with hypochlorite and phenol. The method is subject to interference by
    monoalkyl amines and formaldehyde.

    In the potentiometric method, the ionization potential of
    NH3 -> NH4+ is measured. There can be interference from mercury
    and volatile amines. Chemiluminescent, ultraviolet spectrophotometric,
    or fluorescent derivatization techniques are available for the
    continuous measurement of ammonia concentrations in air. In the
    chemiluminescent method, air is passed through high- and low-
    temperature catalytic converters, which respectively measure
    NOx + NH3, and NOx. The ammonia concentration is obtained by
    subtraction. In ultraviolet spectrophotometry, ammonia (gas) exhibits
    several strong absorption bands between 190 and 230 nm. Absorption at
    204.3 nm is usually used. In the fluorescent derivatization technique,
    1-phthaldehyde derivatization is used. Gas chromatography, with a
    thermal conductor detector, has been used, for example, to measure
    ammonia in tobacco smoke.

    1.3.2  Water

    Ammonia at high concentrations can be measured by a titrimetric
    method. The ammonia in water is distilled into distilled water, which
    is titrated with acid to a methyl red/methylene blue end-point. The
    Nesslerization, indophenol, and potentiometric methods are also
    suitable for measuring ammonia in water.

    1.4  Production and Uses

    Ammonia is one of the most extensively used industrial chemicals,
    production in the USA alone being of the order of 20 million tonnes
    per year. Most of this is used in fertilizers, fibres and plastics,
    and explosives. It is also widely used as a cleaning and descaling
    agent and in food additives, applications that may result in general
    population exposure.

    2.  SUMMARY AND EVALUATION

    2.1  Exposure to Ammonia

    Ammonia is present in the environment as a result of natural processes
    and industrial activity, including certain types of intensive farming.
    Atmospheric ammonia is volatilized from the earth's surface in
    quantities of about 108 tonnes/year, mostly from natural biological
    activity. Industrial activity may cause local and regional elevations
    in emission and atmospheric concentrations. Surface waters receive
    ammonia from point sources, such as effluent from sewage treatment and
    industrial plants, and also through atmospheric deposition, the
    breakdown of vegetation and animal wastes, applied artificial
    fertilizers, and urban run-off.

    Exposure of the skin and eyes or the respiratory tract may occur, but
    the chief effect of ammonia is local irritation due to its alkalinity
    when dissolved in body fluids. Ammonia is an important molecule in the
    intermediate metabolism of nitrogenous compounds and large amounts are
    produced within the intestine each day by the digestion and bacterial
    breakdown of food and food residues. Amounts absorbed from this source
    are much greater than amounts absorbed through occupational exposure
    or the ingestion of food or drinking-water. Atmospheric concentrations
    of ammonia in the community are normally lower than 25 g/m3 but, in
    areas with intensive manure production or use, levels may be as high
    as 200 g/m3. Occupational atmospheric exposure is usually regulated
    to a limit within the range of 18-40 mg/m3, but exposures of up to
    100 mg/m3 are well tolerated for short periods in such situations as
    poultry houses. Ammonia is present in raw foods and is added to
    processed foods. It has been calculated that the daily human intake of
    ammonia and ammonium salts from this source is about 18 mg/day.

    2.2  Fate

    Ammonia released into the atmosphere is deposited on the ground,
    chiefly as ammonium sulfate and ammonium nitrate. Ammonia applied to
    the ground as fertilizer and discharged from point sources, such as
    sewage treatment plants, is similarly converted, though high levels of
    ammonia may occur locally. Ammonia is a key compound in the nitrogen
    cycle. It is converted by soil bacteria to nitrate, which is then
    taken up by plants and incorporated into amino acids and other
    nitrogenous compounds. Plants cannot excrete ammonia and levels
    exceeding those that can be incorporated are toxic.

    2.3  Uptake, Metabolism, and Excretion

    Ammonia is absorbed readily through mucous membranes and the
    intestinal tract, but not through the skin. About 80% of inhaled
    ammonia dissolves in the mucous lining of the upper respiratory tract
    and does not reach the alveoli. Absorbed ammonia joins the body pool

    of ammonia and is rapidly distributed throughout the body. It reacts
    with hydrogen ions, according to the pH, to form ammonium ions. These
    are less mobile than ammonia but are taken up by glutamic acid in many
    tissues and thereafter take part in various transamination reactions.
    In mammals, most ammonia nitrogen is excreted in the urine as urea
    together with a small quantity of ammonium ions. Some is lost in
    desquamated skin; elimination in exhaled air and in faeces is
    insignificant.

    2.4  Effects on Animals and Human Beings

    Acute effects on mammalian and human health occur because of the
    caustic nature of concentrated solutions, the irritant effects of
    ammonia gas, and the extreme cooling that arises on contact with
    liquid ammonia. There are no significant long-term problems for
    terrestrial animals and human beings; atmospheric levels of ammonia
    seldom reach sustained toxic levels.

    The extreme corrosiveness of ammonia has precluded most types of
    toxicological testing, but a 2-h LC50 of 5137 mg/m3 and oral
    LD50s in the range of 4070-5020 mg/kg body weight have been reported
    for rats. A dermal LD50 of > 1000 mg/kg body weight (corrosive) has
    been reported. Because of the physiological nature of its hydrolyric
    products, complex toxicological effects, such as mutagenic,
    reproductive, or carcinogenic effects, would not be expected from
    exposures insufficient to cause local effects.

    Because of the predominance of local effects of little clinical
    interest in cases of accidental contamination, very few clinical cases
    have been described in the literature. Nevertheless, the effects on
    human beings are well known. Skin contact with liquid ammonia results
    in cold burns, usually without blistering or charring. Concentrated
    solutions produce caustic burns on the skin and cause severe corrosive
    injury to the eyes. Long-term contact with more dilute ammonia
    solutions that are not immediately irritant may produce damage to the
    skin as a result of alkaline saponification of protective fats. The
    vapour is irritant to the eyes and the respiratory tract at
    concentrations above about 50 mg/m3 (70 ppm).

    Mild irritation can occur with short-term exposure to concentrations
    below about 150 mg/m3 (210 ppm). Irritant damage to the bronchial
    epithelium produces oedema and bronchospasm resulting in bronchial
    narrowing, which will be manifested progressively by tightness of the
    chest, wheeze, and dyspnoea. Reactive hypersecretion of mucus produces
    cough and sputum and there is the possibility of bronchial obstruction
    and atelectasis. Irritant damage to the alveolar membrane leads to
    exudative pulmonary oedema with restricted diffusion and hypoxia,
    frothy blood-tinged sputum, and the possibility of healing by scarring
    with a permanent restrictive defect. Severe acute over-exposures can
    lead to death within minutes. It is possible that repeated exposure to

    irritant levels insufficient to cause severe immediate symptoms may
    give rise to progressive impairment of lung function. Apart from
    scarring at the site of contact (including corneal opacity and
    pulmonary fibrosis), permanent or delayed effects following over-
    exposure are not expected in survivors.

    2.5  Effects on Organisms in the Environment

    Concern regarding ammonia is related to its environmental effects;
    there is extensive literature on the effects on both plant and aquatic
    life and on the circumstances giving rise to high levels in the
    aquatic environment, air, or soil.

    Ammonia in the form of a liquid, concentrated solution, or at a high
    vapour concentration, will destroy most living organisms. However, the
    material is so readily diluted and degraded in the environment that
    accidental spillages or emissions will not persist or be widely
    dispersed and will not have any impact other than the degradation
    processes. Nevertheless, persistently high concentrations of ammonia
    may occur in the atmosphere where there is intensive use or production
    of animal manure in farming. High concentrations may also occur in
    water in certain elevated, isolated lakes, and where sewage is
    discharged. Ammonia present in water as ammonium ions at sufficiently
    high concentrations can be highly toxic for fish and toxic for aquatic
    plants.

    3.  CONCLUSIONS AND RECOMMENDATIONS

    The effects of ammonia on human beings are mainly due to its alkaline
    corrosiveness. Severe vapour exposures may leave a residual
    restrictive defect in lung function. Strict adherence to an
    occupational exposure limit of about 20 mg/m3 (25 ppm) and care in
    the handling of solutions and liquid ammonia effectively prevent
    health effects. Spillages will sterilize the area immediately
    affected; long-term discharges and/or emissions may have adverse
    effects on organisms in the environment.

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

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

    The main human health hazard is the extreme irritancy and
    corrosiveness of both concentrated solutions and the vapour, and the
    possibility of cold burns from splashes with liquid ammonia.

    As far as possible, ammonia, in the form of a liquid, gas, or
    concentrated solution, should be handled remotely in entirely closed
    systems. Impervious clothing and gloves, and eye and face protection,
    should be used for sampling and other operations where there is open
    exposure. Particular care should be taken to wash out thoroughly pumps
    and other equipment that has contained or been used for transferring
    ammonia prior to disassembly or maintenance.

    The human health hazards, together with preventive and protective
    measures and first-aid recommendations, are listed in the following
    Summary of Chemical Safety Information.

    4.1.1  Advice to physicians

    No specific antidote is known. Irrigate affected eyes and skin burns
    with water and treat conventionally. Severe and extensive burns will
    require fluid replacement and correction of metabolic acidosis and
    will benefit from treatment in a specialist burns unit. Eye injuries
    should be assessed by an ophthalmologist, where possible. In case of
    ingestion of ammonia solution, the oral cavity should be examined for
    burns. If burns are noted, the oesophagus and stomach should be
    examined (gastroscope/fibreoptoscope). Treat symptomatically according
    to the degree and extent of burns.

    After severe vapour exposure, the risk of delayed pulmonary oedema may
    be sufficient to admit 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 maybe given to reduce bronchospasm and dyspnoea.
    Where there are immediate respiratory symptoms suggesting lower airway
    exposure, it will probably be beneficial to administer steroids to
    minimize chemical pneumonitis and scarring. Steroid administration may
    be by the intravenous injection of methylprednisolone in doses up to
    30 mg/kg initially with subsequent smaller doses, or by the 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
    torso upright and oxygen should be administered. Diuretics, morphine,
    and theophylline derivatives are of little benefit, since the oedema
    is 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.

    4.1.2  Health surveillance advice

    It may be advisable to exclude persons with pre-existing respiratory
    disease from working with respiratory irritants such as ammonia.

    Wherever measured exposures are close to the occupational exposure
    limit or there is dependence on personal respiratory protection to
    limit exposure, it is wise to undertake regular measurements of
    pulmonary function to ensure that there is no deterioration beyond
    that normally expected with ageing.

    4.2  Explosion and Fire Hazards

    Ammonia does not readily burn or explode. Fire-fighters should wear
    compressed-air breathing apparatus.

    4.3  Storage

    Ammonia solutions should be stored in suppliers' properly sealed and
    labelled drums or in a suitable bulk container. These should be housed
    in a cool, dry, well-ventilated place. Handle drums carefully to avoid
    puncturing. Liquid ammonia can only be stored in pressure vessels at
    ambient temperature or refrigerated. Refrigeration systems should be
    able to withstand pressures of the order of 10 bar, in case the
    refrigeration fails. Precautions appropriate for the inspection and
    maintenance of pressure vessels should be taken to prevent rupture or
    leaks.

    4.4  Transport

    In case of accident, stop the engine and keep upwind. If the vapour
    cloud drifts towards an inhabited area, warn the inhabitants. Evacuate
    areas close to spillage if this can be done without risking exposure.

    4.5  Spillage and Disposal

    4.5.1  Spillage

    Spillages of liquid or concentrated solutions should only be dealt
    with by trained personnel wearing protective clothing and full-face
    mask, positive-pressure breathing apparatus. Liquid spillages will
    rapidly vaporize and disperse.

    4.5.2  Disposal

    Liquid spillages may be washed into a drain and vapour may be "knocked
    down" with water spray. Drainage into a sewer or large water body is
    possible when the effect of the resulting solution is judged to be
    less severe than the effect of the vapour. Spillages of solutions
    should be washed away with plenty of water. If ammonia has entered a
    watercourse or sewer, or has contaminated soil or vegetation, advise
    the police or public authorities.


        SUMMARY OF CHEMICAL SAFETY INFORMATION

    AMMONIA
    CAS registry number: 7664-41-7; RTECS number: BO 0875000
    In aqueous solution, ammonia forms ammonium (NH4+) and hydroxyl (OH-) ions
                                                                                                                                              
    PHYSICAL PROPERTIES                                                                            OTHER CHARACTERISTICS
                                                                                                                                              

    Melting point (C)                              -77.7                                          Ammonia is a colourless, acrid-smelling, low
    Boiling point (C)                              -33.35                                         density gas at ambient temperature and
    Solubility in water                             high; reacts                                   pressure; it can be stored and transported
    Relative density (0C)                          0.771                                          as a liquid at a pressure of 10 atm;
    Relative density (-79C)                        0.817                                          ammonia dissolves readily in water
    Relative vapour density (25C)                  0.6                                            where it forms and is in equilibrium with
    Vapour pressure (25.7C)                        10 bar                                         ammonium ions; solutions are highly
    Autoignition point (C)                         651                                            alkaline; splashes of liquid ammonia
    Lower explosion limit                           16%                                            evaporate rapidly, extracting latent heat
    Upper explosion limit                           25%                                            of vaporization from their surroundings
    Relative molecular mass                         17.03                                          and thus causing cold burns when splashed
                                                                                                   on the skin; ammonia burns to form oxides
                                                                                                   of nitrogen and water and will explode
                                                                                                   within a rather narrow range of
                                                                                                   concentrations
                                                                                                                                              
    HEALTH HAZARDS/SYMPTONS                         PREVENTION AND PROTECTION                      FIRST AID
                                                                                                                                              

    Ammonia vapour/fumes

    EYES: severe irritation and                     Proper containment or efficient local          Remove patient from exposure; irrigate
    lacrimation                                     exhaust ventilation so that breathing          eyes for at least 15 minutes with a gentle
                                                    zone concentrations are below the              flow of fresh potable water or sterile eye-
                                                    occupational exposure limit; otherwise,        irrigation fluid; seek medical attention
                                                    positive-pressure demand compressed-
                                                    air breathing apparatus or other effective
                                                    respiratory protection with a full
                                                                                                                                              

    (cont'd)
                                                                                                                                              
    HEALTH HAZARDS/SYMPTONS                         PREVENTION AND PROTECTION                      FIRST AID
                                                                                                                                              

                                                    facepiece should be worn so that
                                                    complete protection of the eyes and
                                                    respiratory tract is assured

    INHALATION: sensory irritation at               See above                                      Remove patient from exposure; if not
    lower concentrations; at higher                                                                breathing, give artificial respiration;
    concentrations, bronchial and lower                                                            maintain airway;, keep patient at rest and
    airway irritation leading to tightness                                                         seated upright if conscious and breathless;
    in the chest, coughing, wheezing,                                                              administer oxygen; send to hospital or a
    breathing difficulty, blueness of the                                                          doctor
    lips

    Anhydrous liquid ammonia

    SKIN/EYES: severe cold and                      Proper containment in well-maintained          Do not overheat affected part; apply dry
    possibly frostbite, in which                    pressure vessels and lines; when               dressing; usually, healing will take place
    skin will be pale and usually                   sampling, making connections, and at           without grafting or other intervention;
    anaesthetic, but without blistering             other times when exposure could                irrigate eyes as for any chemical splash;
                                                    occur, full eye, face, and respiratory         send patient to a doctor, preferably an
                                                    protection, gloves, boots, and                 ophthalmological specialist
                                                    an impervious suit should be worn

    Ammonia solutions

    EYES: injuries from concentrated                Solutions must be held in properly             Irrigate eyes immediately and thoroughly
    solutions are severe; conjunctival              constructed and vented containers;             with large quantities of fresh potable
    and corneal damage and penetration              hand and full-face protection and              water for at least 15 minutes; seek medical
    of the bulb will occur                          boots, gloves, and an impervious               advice; if there is corneal damage, instill
                                                    apron or suit should be worn whenever          antibiotics and, if possible, obtain advice
                                                    containers or pipework are opened;             from an ophthalmological specialist
                                                    if local exhaust ventilation is
                                                    inadequate to reduce vapour concentrations
                                                                                                                                              

    (cont'd)
                                                                                                                                              
    HEALTH HAZARDS/SYMPTONS                         PREVENTION AND PROTECTION                      FIRST AID
                                                                                                                                              

                                                    below the occupational exposure limit,
                                                    respiratory protection should be worn

    SKIN: irritation, redness, and                  See above                                      Remove all contaminated clothing
    caustic burns                                                                                  immediately, wash skin liberally with water
                                                                                                   hydrocortisone cream may reduce pain
                                                                                                   and inflammation in areas of superficial
                                                                                                   damage and erythema; full-thickness
                                                                                                   damage may require grafting,
                                                                                                   according to its extent and position

    INGESTION: irritation, caustic                  Avoid ingestion of ammonia solutions           Do not induce vomiting; rinse the mouth
    burns                                                                                          with water; if the concentration of the
                                                                                                   ammonia solution is known to be 10% or
                                                                                                   less, give water by mouth to dilute the
                                                                                                   solution; if the concentration is unknown or
                                                                                                   is greater than 10%, give nothing by mouth
                                                                                                   and send the patient to hospital without
                                                                                                   delay for examination and treatment
                                                                                                                                              
    SPILLAGE                                        STORAGE                                        FIRE AND EXPLOSION
                                                                                                                                              

    Take appropriate personal                       Ammonia solutions should be stored             Fire: not flammable under normal
    precautions; spillages will tend to             in sealed drums or bulk containers in          conditions
    vaporize and disperse; to assist                a dry, well-ventilated place; liquid           Explosion: none
    disposal, liquid may be washed away             ammonia must be stored in pressure             Fire-extinguishing agents: foam, carbon
    and vapour "knocked down" by                    vessels and refrigerated                       dioxide, dry chemical
    water spray; if ammonia enters a
    watercourse or sewer, public
    authorities must be informed
                                                                                                                                              
    
    5.  HAZARDS FOR THE ENVIRONMENT AND THEIR PREVENTION

    Ammonia is alkaline and is toxic for animals and plants, causing
    convulsions in the former and interference with carbohydrate
    metabolism in the latter. Potassium transport across membranes is
    affected in both animals and plants. Persistently high levels of
    discharge into the atmosphere or into water bodies will have adverse
    effects on the environment, animals, and plants. There will only be a
    localized environmental hazard in the vicinity of a spillage,
    emission, or improper disposal (see section 4.5).

    6.  CURRENT REGULATIONS, GUIDELINES, AND STANDARDS

    The information given in this section has been extracted from the
    International Register of Potentially Toxic Chemicals (IRPTC) legal
    file. A full reference to the original national document from which
    the information was extracted can be obtained from IRPTC. When no
    effective date appears in the IRPTC legal file, the year of the
    reference from which the data are taken is indicated by (r).

    The reader should be aware that regulatory decisions about chemicals
    taken in a certain country can only be fully understood in the
    framework of the legislation of that country. The regulations and
    guidelines of all countries are subject to change and should always be
    verified with appropriate regulatory authorities before application.

    6.1  Exposure Limit Values

    Some exposure limit values are given in the following table.

    6.2  Specific Restrictions

    In Japan, Sweden, the United Kingdom, and the USA, ammonia is listed
    as a poison and sale is controlled. In Czechoslovakia and the EEC, the
    use of ammonia in cosmetics is restricted.

    In Sweden and the USA, the use of ammonia as a pesticide is regulated.

    In the EEC, the United Kingdom, and the USA, the storage of ammonia is
    regulated. For the EEC and the United Kingdom, the levels at which
    regulations apply are 60 tonnes and 100 tonnes, respectively.

    6.3  Labelling, Packaging, and Transport

    In the EEC, anhydrous ammonia is classified as toxic and flammable for
    labelling and packaging purposes. The label must read:

          Toxic by inhalation. Keep container tightly closed and in a well
          ventilated place. Keep away from sources of ignition. No
          smoking; in case of insufficient ventilation, wear suitable
          respiratory equipment.

    For ammonia solutions with concentrations of more than 35%, the
    percentage concentration must be stated on the label which must read:

          Causes burns; irritating to respiratory system and skin; keep
          container tightly closed and dry. In case of contact with eyes,
          rinse immediately with plenty of water and seek medical advice.


        EXPOSURE LIMIT VALUES
                                                                                                                               
    Medium    Specification    Country           Exposure limit description                      Value               Effective
                               organization                                                                            date
                                                                                                                               

    AIR       Occupational     Argentina         Maximum permissible concentration (MPC)                               1979
                                                 - Time-weighted average (TWA)                   18 mg/m3
                                                 - Short-term exposure limit (STEL)              27 mg/m3

                               Austria           Threshold limit value (TLV)                                           1985 (r)
                                                 - Time-weighted average (TWA)                   18 mg/m3
                                                 - Short-term exposure limit (STEL)              27 mg/m3

                               Belgium           Threshold limit value (TLV)                                           1989 (r)
                                                 - Time-weighted average (TWA)                   18 mg/m3
                                                 - Short-term exposure limit (STEL)              27 mg/m3

                               Canada            Threshold limit value (TLV)                                           1980
                                                 - Time-weighted average (TWA)                   18 mg/m3
                                                 - Short-term exposure limit (STEL)              27 mg/m3

                               Czechoslovakia    Maximum allowable concentration (MAC)                                 1985
                                                 - Time-weighted average (TWA)                   20 mg/m3
                                                 - Ceiling value (CLV)                           40 mg/m3

                               Finland           Maximum permissible concentration (MPC)                               1989 (r)
                                                 - Time-weighted average (TWA)                   18 mg/m3

                               German            Maximum allowable concentration (MAK)                                 1988 (r)
                                Democratic       - Short-term exposure limit (STEL)              20 mg/m3
                                Republic

                               Germany,          Maximum workplace concentration (MAC)                                 1989 (r)
                                Federal          - Time-weighted average (TWA)                   35 mg/m3
                                Republic of      - Short-term exposure limit (STEL)              70 mg/m3
                                                   (5 min, 8/shift)
                                                                                                                               

    (cont'd)
                                                                                                                               
    Medium    Specification    Country           Exposure limit description                      Value               Effective
                               organization                                                                            date
                                                                                                                               
    AIR       Occupational     Hungary           Maximum allowable concentration (MAC)                                 1985 (r)
                                                 - Time-weighted average (TWA)                   20 mg/m3
                                                 - Short-term exposure limit (STEL)              20 mg/m3
                                                   (30 min)

                               Italy             Threshold limit value (TLV)                                           1985 (r)
                                                 - Time-weighted average (TWA)                   20 mg/m3

                               Japan             Maximum allowable concentration (MAC)                                 1986 (r)
                                                 - Time-weighted average (TWA)                   18 mg/m3

                               Netherlands       Maximum limit (MXL)                                                   1987 (r)
                                                 - Time-weighted average (TWA)                   18 mg/m3

                               Poland            Maximum permissible concentration (MPC)                               1985 (r)
                                                 - Ceiling value (CLV)                           20 mg/m3

                               Romania           Maximum permissible concentration (MPC)                               1985 (r)
                                                 - Time-weighted average (TWA)                   20 mg/m3
                                                 - Ceiling value (CLV)                           30 mg/m3

                               Sweden            Hygienic limit value (HLV)                                            1983
                                                 - Time-weighted average (TWA)                   18 mg/m3
                                                 - Ceiling value (CLV)                           35 mg/m3
                                                   (5-min time-weighted average)

                               Switzerland       Maximum workplace concentration (MAK)                                 1987 (r)
                                                 - Time-weighted average (TWA)                   18 mg/m3

                               United            Recommended exposure limit (RECL)                                     1987 (r)
                               Kingdom           - Time-weighted average (TWA)                   18 mg/m3
                                                 - Short-term exposure limit (STEL)              27 mg/m3
                                                   (10-min time-weighted average)
                                                                                                                               

    (cont'd)
                                                                                                                               
    Medium    Specification    Country           Exposure limit description                      Value               Effective
                               organization                                                                            date
                                                                                                                               

    AIR       Occupational     USA (ACGIH)       Threshold limit value (TLV)                                           1987
                                                 - Time-weighted average (TWA)                   18 mg/m3
                                                 - Short-term exposure limit (STEL)              27 mg/m3

                               USA (OSHA)        Permissible exposure limit (PEL)                                      1987
                                                 - Time-weighted average (TWA)                   35 mg/m3

                               USSR              Maximum allowable concentration (MAC)                                 1977
                                                 - Ceiling value (CLV)                           20 mg/m3

    AIR       Ambient          USSR              Maximum allowable concentration (MAC)                                 1984
                                                 - Daily average                                 0.04 mg/m3
                                                 - Peak concentration (1 per day)                0.12 mg/m3

              Emissions        Japan             Maximum limit (MXL)                             3.5 mg/m3             1982 (r)

    WATER     Surface          Czechoslovakia    Maximum allowable concentration (MAC)           3.0 mg/litre          1975

                               EEC               Quality standard for surface water                                    1977
                                                 intended for abstraction of drinking-
                                                 water
                                                 - Normal water treatment                        1.5 mgNH4/litre
                                                 - Intensive water treatment                     4.0 mgNH4/litre
                                                 Guideline values
                                                 - Simple water treatment                        0.05 mgNH4/litre
                                                 - Normal water treatment                        1.0 mgNH4/litre
                                                 - Intensive water treatment                     2.0 mgNH4/litre

                               Netherlands       Basic quality standard for surface              0.02 mg N/litre       1986
                                                 water in general

                               USSR              Maximum allowable concentration (MAC)           2.0 mg N/litre        1983
                                                                                                                               

    (cont'd)
                                                                                                                               
    Medium    Specification    Country           Exposure limit description                      Value               Effective
                               organization                                                                            date
                                                                                                                               

    WATER     Drinking-        Czechoslovakia    Maximum allowable concentration (MAC)           0.5 mg/litre          1975

                               EEC               Maximum allowable concentration (MAC)           0.5 mg NH4/litre      1982

                                                 Guideline value                                 0.05 mg NH4/litre

                               Netherlands       Limit value                                     10.0 mg N/litre       1986

    FOOD                       FAO/WHO           No ADI allocated                                                      1982 (r)
                                                                                                                               
    
    For ammonia solutions with concentrations of 10-35%, the percentage
    concentration must be stated on the label which must read:

          Irritation to eyes, to respiratory system and skin; keep out of
          reach of children; in case of contact with eyes, rinse
          immediately with plenty of water and seek medical advice.

    The maximum concentration of ammonia in finished cosmetic products
    must not exceed 6% calculated as NH3. If the concentration exceeds
    2%, the label must read:

          Contains ammonia.

    In the EEC, paints, varnishes, printing inks, adhesives, and similar
    products that contain ammonia in solution at concentrations greater
    than 35% are considered toxic and corrosive and, at concentrations of
    10-35%, as harmful and irritant, and must be packaged and labelled
    accordingly. Ammonia is also controlled by the EEC Dangerous Products
    Directive (88/379/EEC).

    6.4  Waste Disposal

    No recommendations made by IRPTC.

    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. 2A, New York, Wiley - Interscience, John Wiley &
    Sons.

    GOSSELIN, R.E., HODGE, H.C., SMITH, R.P., & GLEASON, M.N. (1976)
     Clinical toxicology of commercial products, 4th ed., Baltimore,
    Maryland, Williams and Wilkins Company.

    DUTCH CHEMICAL INDUSTRY ASSOCIATION (1980)  Handling chemicals safely,
    2nd ed., Dutch Association of Safety Experts, Dutch Chemical Industry
    Association, Dutch Safety Institute.

    IRPTC (1989)  Data profile (legal file, waste disposal file, treatment
     of poisoning file), Geneva, International Register of Potentially
    Toxic Chemicals.

    MATERIAL SAFETY DATA SHEETS COLLECTION PLUS UPDATING SERVICE (1984)
    New York, Genium Publishing Corporation.

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

    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).

    WHO (1986)  Environntental Healtit Criteria 54: Ammonia, Geneva,
    World Health Organization.
    


    See Also:
       Toxicological Abbreviations
       Ammonia (EHC 54, 1986)