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    IPCS INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY
    Health and Safety Guide No. 11

    TETRADIFON
    HEALTH AND SAFETY GUIDE






    UNITED NATIONS ENVIRONMENT PROGRAMME

    INTERNATIONAL LABOUR ORGANISATION

    WORLD HEALTH ORGANIZATION




    WORLD HEALTH ORGANIZATION, GENEVA 1987

    This is a companion volume to Environmental Health Criteria 67:
    Environmental Health Criteria 67: Tetradifon

    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 154367 1
    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 1987

    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

    IPCS

    HEALTH AND SAFETY GUIDE FOR TETRADIFON

    INTRODUCTION

    HOW TO USE THE GUIDE

    1. PRODUCT IDENTITY AND USES

         1.1. Identity
         1.2. Physical and chemical properties
         1.3. Composition
         1.4. Uses

    2. SUMMARY AND EVALUATION

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

    3. CONCLUSIONS AND RECOMMENDATIONS

    4. HEALTH HAZARDS FOR MAN, PREVENTION AND PROTECTION, EMERGENCY
         ACTION

         4.1. Main hazards for man, prevention and protection, first aid
               4.1.1. Prevention and protection
               4.1.2. First aid
         4.2. Advice to physicians
         4.3. Explosion and fire hazards
               4.3.1. Fire-extinguishing agents
         4.4. Storage and transport
         4.5. Spillage and disposal

    5. INTERNATIONAL CHEMICAL SAFETY CARD

    6. HAZARDS FOR THE ENVIRONMENT AND THEIR PREVENTION

    7. CURRENT REGULATIONS, GUIDELINES, AND STANDARDS

         7.1. Exposure limit values
         7.2. Specific restrictions
         7.3. Transport and labelling
    

    INTRODUCTION

    The International Programme on Chemical Safety is responsible for the
    publication of a series of Environmental Health Criteria documents,
    each of which assesses the existing information on the relationship
    between exposure to a specific chemical, mixture of chemicals, or
    combination of chemicals and physical and biological agents, and man's
    health and the integrity of the environment. The documents provide
    guidelines for setting exposure limits consistent with the protection
    of human health and the environment.

    To facilitate the application of these guidelines in national chemical
    safety programmes, "Health and Safety Guides" are being prepared,
    highlighting the information contained in the documents for those who
    need to know the health and environmental issues involved, but not the
    scientific details. The Guides include advice on preventive and
    protective measures and emergency action.

    Review and revision of the information in this Health and Safety Guide
    will take place in due course, and the eventual aim is to use
    standardized terminology. We should be grateful if you would help by
    telling us of any difficulties encountered in using the information in
    this guide.

    Comments please, addressed to:

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

    HOW TO USE THE GUIDE

    All people in the work-place environment should be given the relevant
    written information in this book, supplemented by a clear, personal
    explanation to ensure that they are fully aware of the dangers and the
    current courses of protective and emergency action.

    The International Chemical Safety Card should be displayed as directed
    and its contents clearly explained to all working personnel. Medical
    staff should be fully conversant with the medical information to
    ensure they can act rapidly and efficiently in an emergency. Posters
    should be used to give impact to basic safety measures.

                                * * *

    Further copies of the Health and Safety Guide and, for those requiring
    more detailed scientific information, the relevant Environmental
    Health Criteria publication, are available to order.

    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:        C12H6Cl4O2S

    Chemical structure:      CHEMICAL STRUCTURE 1

    Common trade names:      Akaritox, Aredion, Duphar 23737,
                             ENT 23737, FMC 5488, Mition,
                             NIA 5488, Polacaritox, Roztoczol,
                             Roztozol, Tedion V18, Tetradichlone
                             (a complete list of trade names is
                             available from IRPTC)

    CAS chemical name:       1,2,4-trichloro-5-[(4-chlorophenyl)-
                             sulfonyl]-benzene

    Synonyms:                4-chlorophenyl-2,4,5-trichlorophenyl
                             sulfone, 2,4,4',5-tetrachlorodiphenyl
                             sulfone

    CAS registry number:     116-29-0

    1.2  Physical and Chemical Properties

    Technical tetradifon is a white crystalline solid, the solubility of
    which, at room temperature in different organic solvents, varies from
    10 g/litre (in kerosene and methanol) to 255 g/litre (in chloroform).

    Tetradifon is resistant to hydrolysis by acid and alkali and is
    non-corrosive. Particle size has a strong influence on its biological
    effectiveness in that small particles show a better rain resistance
    than larger ones. For details of the physical and chemical properties
    of tetradifon, see the Sample International Chemical Safety Card.

    1.3  Composition

    Technical tetradifon is more than 94% pure. Trace amounts of
    2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and highly-chlorinated
    dibenzodioxins but not 2,3,7,8-TCDD have been reported as impurities
    of tetradifon. However, information on specific isomers is lacking.
    The contribution of these chemicals and of other compounds, such as
    2,4,5-T, to the toxicity of the parent compound is not known at
    present. The formulated product may be more toxic, depending on the
    other compounds present in the formulation. The toxicity may also vary
    with the purity of the product.

    1.4  Uses

    Tetradifon is used as a non-systemic acaricide, which is toxic for the
    eggs and all non-adult stages of a wide range of phytophagous mites.
    It is used in horticulture, including domestic greenhouses, mainly on
    top-fruit, vegetables, ornamentals, hops, cotton, and sugarcane. It is
    also used in forestry.

    2.  SUMMARY AND EVALUATION

    2.1  Exposure to Tetradifon

    The general population is mainly exposed to tetradifon through food,
    but market-basket studies have shown that, at normal application rates
    as an acaricide, residues are virtually absent from food.

    2.2  Effects on the Environment

    Although tetradifon is widely used as an acaricide, there are no
    indications, at present, that it causes an environmental pollution
    problem. Tetradifon is persistent and only slightly mobile in soils.
    The compound degrades more rapidly under aerobic conditions. Both the
    parent compound and its initial break-down product in the soil are
    adsorbed on soil particles and resist leaching.

    Tetradifon did not produce any toxic effects on cultures of  Chlorella
     pyrenoidova or when sprayed on the leaves of papaya plants. The
    short-term toxicity of the compound is low for birds, moderate for
    fish, and moderate to high for aquatic crustacea. Tetradifon is
    relatively nontoxic for honey bees, and its toxicity is low for other
    insects. However, it may synergize with insecticides to increase their
    insecticidal potency. It does not bioaccumulate significantly in fish.
    No long-term toxicity data are available and, therefore, more subtle
    hazards cannot be adequately evaluated. On the basis of the data
    available, tetradifon does not present a short-term threat for the
    environment.

    2.3  Uptake, Metabolism, and Excretion

    In the rat, most orally administered tetradifon is excreted via the
    bile in the faeces (70% within 48 h). Part of the remainder is
    distributed in all organs and tissues. On continued dosing, tetradifon
    was detected in the adipose tissue of beef cattle. It is not known
    whether tetradifon is excreted in milk.

    2.4  Effects on Animals

    The oral LD50 for tetradifon in rats ranges from 5 000 to
    14 700 mg/kg body weight. WHO (1984) categorized tetradifon as a
    technical product that is unlikely to present any acute hazards, if
    used as recommended. In a 90-day study on rats, 50 mg/kg diet was a
    no-observed-adverse-effect level. At higher dose levels and also with
    long-term administration (2 years), induction of microsomal liver
    enzymes occurred, with increased liver weight. Histological changes in
    the thyroid were also seen.

    No effects on reproduction were found in a 2-generation study on rats
    administered tetradifon in the diet. In a 90-day study on the F2b
    generation, the only effects on the offspring included a reduction in
    body weight gain and an increased dose-related incidence of dilated
    renal pelvis.

    Enlarged livers were seen in dogs at a dietary concentration of
    5 000 mg/ kg. Kidney damage in the form of small infarct-like spots in
    the outer cortical layer was reported at a dietary level of
    5 000 mg/kg and in one of 4 dogs at 1000 mg/kg diet. The no-observed-
    adverse-effect level was roughly equivalent to a daily intake of
    12.5-25 mg/kg body weight.

    Tetradifon was negative in short-term  in vitro tests for genetic
    activity. Negative results were obtained in a screening test for
    carcinogenicity in mice. However, the screening test was considered to
    be inadequate for the evaluation of the carcinogenicity of this
    compound.

    2.5  Effects on Human Beings

    No adverse health effects from exposure to tetradifon have been
    reported in man.

    3.  CONCLUSIONS AND RECOMMENDATIONS

    In spite of the fact that the information available for the evaluation
    of the toxic effects of tetradifon is incomplete and not always up to
    present-day standards, there are no indications, at present, that its
    use as an acaricide, at recommended levels, causes any health or
    safety hazards for the general population, exposed workers, or the
    environment.

    The following recommendations were made by the Task Group:

    1.   More information is needed on metabolism, on the effects on
         reproduction, and on long-term toxicity including
         carcinogenicity.

    2.   The purity of the products registered and used should be
         ascertained, since the contamination of the product by some
         chlorinated compounds may increase its toxicity.

    From: Environmental Health Criteria 67: Tetradifon

    4.  HEALTH HAZARDS FOR MAN, PREVENTION AND PROTECTION, EMERGENCY
        ACTION

    4.1  Main Hazards for Man, Prevention and Protection, First Aid

    The toxicity of technical tetradifon for man is thought to be low, and
    no adverse health effects from exposure to tetradifon have been
    reported. The toxicity and hazard of a formulation may largely depend
    on the vehicle used.

    4.1.1  Prevention and protection

    In spite of the low toxicity and hazard of tetradifon, the following
    precautions should be observed during handling and use, in order to
    reduce the risk of accidental contamination:

    (a)  Avoid contact with the skin and eyes. If eyes become
         contaminated, flush with water. If irritation persists, obtain
         medical attention.

    (b)  Do not smoke, drink, or eat in the work-place. Wash hands and any
         exposed skin before eating, drinking, smoking, and after work.

    (c)  Avoid raising a dust cloud when handling wettable powder
         formulations.

    (d)  Avoid breathing dust from powder products.

    (e)  When unloading and handling containers, wear protective PVC or
         neoprene gloves.

    (f)  When handling leaking containers or when dealing with leaks and
         spills, wear overalls and PVC or neoprene gloves and boots. If
         overalls become contaminated, change and wash them thoroughly
         before re-use.

    (g)  Store products in original containers out of reach of children
         and away from food and feeding stuffs.

    4.1.2  First aid

    Poisoning by tetradifon is unlikely unless there has been gross
    (negligent) exposure or intentional ingestion. In cases of
    overexposure, apply routine first aid measures.

    If material has been spilled on the skin, immediately remove the
    patient from the source of contamination, remove all contaminated
    clothing, and wash affected areas with soap and running water.

    If material is in the eyes, flush with clean water for at least 15
    minutes.

    Keep patient prone and quiet. Start artificial respiration
    immediately, if patient is not breathing.

    Never give anything by mouth to an unconscious person.

    In serious cases, medical attention should be sought.

    4.2  Advice to Physicians

    The human toxicity of tetradifon is believed to be low. There is no
    specific antidote. Treat symptomatically when required. In cases of
    ingestion, gastric lavage may be indicated.

    4.3  Explosion and Fire Hazards

    Technical tetradifon is not explosive and is not highly flammable, but
    liquid formulations may be, depending on the solvent used.

    4.3.1  Fire-extinguishing agents

    Fight small fires with carbon dioxide, dry powder, or alcohol-
    resistant Foam. Confine the use of water sprays to the cooling of
    unaffected stock only, thus avoiding the accumulation of polluted run-
    off from the site. Fire service personnel should be advised that self-
    contained breathing apparatus may be required, because noxious fumes
    may be generated through a fire.

    4.4  Storage and Transport

    All products should be stored in secure buildings, out of reach of
    children and animals, and local transport regulations should be
    complied with. Containers should be sound and well labelled.

    4.5  Spillage and Disposal

    Keep spectators away from any leakage. Prevent contamination of other
    goods or cargo, or nearby vegetation and waterways.

    Absorb spillage of liquid products with sawdust or sand, sweep up and
    place in separate container.

    Empty any product remaining in damaged or leaking containers into a
    clean empty container, which should be suitably labelled.

    Sweep up any split powder with damp sawdust taking care not to raise a
    dust cloud. Place in separate container for subsequent disposal.

    Contaminated absorbents, used containers, surplus product, etc.,
    should be burnt in an incinerator designed for pesticide disposal.
    When no incinerator is available, bury in an approved dump or in an
    area where there is no risk of contamination of ground or surface
    water. Comply with any local legislation applying to waste disposal.

    5.  INTERNATIONAL CHEMICAL SAFETY CARD

     This card should be easily available to all health workers concerned
     with, and users of tetradifon. It should be displayed at, or near,
     entrances to areas where there is potential exposure to tetradifon,
     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.


        TETRADIFON (technical)
    (2,4,4',5-tetrachlorodiphenylsulfone; C12H6Cl4O2S)
                                                                                                                                           
    PHYSICAL PROPERTIES                                                                  OTHER CHARACTERISTICS
                                                                                                                                           

    Relative molecular mass                         356.04                               Slightly yellow crystalline solid; very stable,
    Melting point (C)                              148-149                              non-corrosive substance; may emit toxic fumes
    Water solubility (20C)                         0.08 mg/litre                        when heated to decomposition
    Density (20C)                                  1.515
    Octanol/water partition coefficient             4.61
    Vapour pressure (20C)                          0.32 x 10-10kPa
                                                                                                                                           
    HAZARDS/SYMPTOMS                                PREVENTION AND                       FIRST AID
                                                    PROTECTION
                                                                                                                                           

    SKIN: Mild irritation                           Wear neoprene gloves,                Remove contaminated clothing; wash with plenty
                                                    face shield                          of water

    EYES: Marginal irritant                         Wear safety goggles, face shield     Flush with clean water for a least 15 minutes

    INHALATION: Irritation of upper                 Local exhaust ventilation;           Fresh air
    respiratory tract                               wear a dust mask

    INGESTION: Not observed                         Unlikely professional hazard         Gastric lavage may be indicated
                                                                                                                                           
    SPILLAGE                                        STORAGE                              FIRE AND EXPLOSION
                                                                                                                                           

    Collect spillage in closed container            Cool and dry storage in original     Not flammable or explosive under normal conditions;
    or dust bin bag; in the case of liquid,         packaging                            fire extinguishing agents include foam, CO2,
    first use absorbant material: clean up                                               and dry chemical
    with water
                                                                                                                                           

    (cont'd)
                                                                                                                                           
    WASTE DISPOSAL
                                                                                                                                           

    Should be burnt in an incinerator               National Occupational Exposure       
    designed for pesticide disposal                 Limit:

                                                    National Poison Control Centre:

    FIGURE 1

                                                                                                                                           
    
    6.  HAZARDS FOR THE ENVIRONMENT AND THEIR PREVENTION

    No effects on the environment have been reported for tetradifon.
    However, contamination of ponds, waterways, and ditches with the
    product or used containers should be avoided. Empty containers should
    be punctured to prevent re-use.

    7.  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.

    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. A full reference to the
    original national document from which the information was extracted
    can be obtained from the IRPTC.a

    When no effective date appears in the IRPTC legal file, the
    publication year of the national document from which the data are
    taken is mentioned; where appropriate, this is indicated by (r).

    7.1  Exposure Limit Values

    Some exposure limit values are given in the following table.

    7.2  Specific Restrictions

    In Czechoslovakia (effective date: 1981) and the United Kingdom
    (1983 (r)), the substance is approved as a pesticide or acaricide, and
    specified uses, limitations, and safety precautions are listed. In the
    USSR, the substance is approved as an insecticide for agricultural use
    and application; dose, mode, and treatment frequency are specified
    (effective date: 1982).

    In Sweden, the substance is an active ingredient in pesticide
    formulations that are registered at the products control board and
    therefore may be marketed and used. The formulations may be sold only
    to persons authorized to use such formulations (1984 (r)).

                 

    a  International Register of Potentially Toxic Chemicals, Palais des
       Nations, 1211 Geneva 10, Switzerland (Telephone No. 988400 - 985850).

    7.3  Transport and Labelling

    The United Nations Committee of Experts on the Transport of Dangerous
    Goods classifies tetradifon as a poisonous substance (Class 6.1)
    presenting minor danger for packing purposes when the active
    ingredient constitutes 25 - 100% of the formulation (1982 (r)).

    The recommended label is:

    FIGURE 2


        SOME EXPOSURE LIMIT VALUES
                                                                                                                                  
    MEDIUM    SPECIFICATION          COUNTRY                         EXPOSURE LIMIT DESCRIPTION             VALUE       EFFECTIVE
                                                                                                            (mg/kg)       DATE
                                                                                                                                  

    FOOD      Plant                  Argentina                       Maximum limit                          1-5           1969
              Meat, milk                                                                                    0             1969
              Mint                                                                                          100           1969
              Hops                                                                                          30            1969
              Dried hops                                                                                    120           1969

    FOOD      Plant products         Brazil                          Acceptable limit                       1-5           1984 (r)
              (specified)                                            (security interval: 2-14 days)

    FOOD      Plant (specified)      Germany, Federal Republic of    Maximum residue limit                  1.5           1984
              Plant products                                         Maximum residue limit                  0.05          1984
              (specified)

    FOOD      Food products          Kenya                           Maximum limit                          1-100         1978 (r)
              (specified)

    FOOD      Fruits, vegetables     Sweden                          Maximum acceptable concentration       2             1985

    FOOD      Food products          USA                             Residue tolerance                      8-120         1981 (r)
              (specified)
              Raw agricultural                                       Acceptable residue limit               0-100         1981 (r)
              products (specified)

    FOOD      Food products          USSR                            Maximum residue limit                  0.1-0.7       1983
              (specified)
                                                                                                                                  
        


    See Also:
       Toxicological Abbreviations
       Tetradifon (EHC 67, 1986)
       Tetradifon (ICSC)