EPA-560/5-77-001
               PRIORITIZED GUIDELINES FOR
             ENVIRONMENTAL FATE TESTING
         OF ONE HALOGENATED HYDROCARBON
                     CHLOROBENZENE
                         January 1977
                        FINAL REPORT
                   Office of Toxic Substances
              U.S. Environmental Protection Agency
                    Washington, D.C.  20460

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EPA-560/5-77-001                                                       TR 76-591
                         Prioritized Guidelines for
                         Environmental Fate Testing
                       of One Halogenated Hydrocarbon:
                                Chlorobenzene
                                   Author
                              Philip H. Howard
                                January 1977
                                Final Report
                       Contract No. 68-01-2679 Task 3
                                 \
                              Project  Officer:
                              Patricia Hilgard
                                 Prepared  for:
                          Office  of  Toxic  Substances
                     U.S.  Environmental Protection Agency
                           Washington,  B.C.    20460
 Document  is  available  to  the  public  through  the  National  Technical  Information
                    Service,  Springfield, Virginia   22151

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                                 NOTICE






     This report has been reviewed by the Office of Toxic Substances, EPA, and




approved for publication.  Approval does not signify that the contents necessarily




reflect the views and policies of the Environmental Protection Agency, nor does




mention of trade names or commercial products constitute endorsement or recom-




mendation for use.

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                             Table of Contents                          Page


I.   Introduction                                                         1

II.  Development of Environmental Fate Testing Protocols for              3
     Toxic Substances

     A.   Existing Environmental Fate Testing Documents                   3

     B.   Chlorobenzene Case Study                      .                  6

III. Conclusions and Recommendations                                     20

REFERENCES                                                               21
                                    ii

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                             List of Tables                            Page


1    Chemical Marketing Data for Chlorobenzene                           8

2    Physical Properties of Chlorobenzene                               10

3    Calculations of Bioaccumulation and Evaporation Rates From
     Physical Properties                                                12
                                      iii

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I.   INTRODUCTION




     In order to assess the potential environmental hazards associated with the




commercial use of chemical substances, tests on their environmental fate and




biological effects need to be conducted.  The number, extensiveness, and cost




of these tests should be dependent upon such factors as the quantity of the




chemical being used and the likelihood of the chemical being released to the




environment.  In order to provide a relationship between environmental exposure




and the degree of testing, priorities and protocols for the tests are required.




This report is a first step in developing such priorities and protocols for




determining the fate of chemicals which are the responsibility of EPA's Office




of Toxic Substances.  In this report, environmental fate is defined as all trans-




port (including bioconcentration) and alteration (including degradation) pro-




cesses which take place in nature; excluded are any biological effects.  The




fate of an environmental contaminant has considerable impact upon its potential




adverse effects since the environmental fate processes determine the form and




quantity of the contaminant that may reach a sensitive biological site.




     One case study chemical was selected from the chlorinated hydrocarbon




family, a group of chemicals that has provided numerous environmental pollution




problems (e.g. DDT, dieldrin and related compounds, PCB's, hexachlorobenzene).




Using this sample, the types of environmental testing will be discussed and




priorities for testing will be suggested.  The case study compound, chloro-




benzene, provides an example of a high production volume, water insoluble,




fairly volatile chemical that is probably released to the environment in sig-




nificant quantities.  However, there are many commercial organic compounds




(e.g., gases and solids, and compounds capable of dissociation), as well as

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other chemical compounds, for which the test case will provide little insight




into the type of environmental fate testing that should be undertaken.  These




compounds need to be considered in future reports.

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II.  DEVELOPMENT OF ENVIRONMENTAL FATE TESTING PROTOCOLS FOR TOXIC SUBSTANCES

     A.   Existing Environmental Fate Testing Documents

          The Office of Toxic Substances, EPA, has funded two companion studies

which have reviewed and evaluated test methods for determining environmental

persistence and routes of degradation (Howard e_t al., 1975) and environmental

transport (Witherspoon et^ a^., 1976).  These reports  provide a good reference

to the test methods that are available, their reliability and reproducibility,

and relative cost, but little attempt was made to design protocols or prioritize

the tests for individual chemicals.

          In 1974, Woodard conducted a survey of test methods that were used by

industry to indicate health hazards from individual chemicals.  He organized

the methods into categories of studies that were conducted in response to four

levels of exposure.  The levels of exposure with the  environmental fate tests

that are conducted follows:

          Level I Exposure - chemical is still in laboratory, or pilot plant
               production where a limited number of persons may be exposed.

                    Fate Tests:  None

          Level II Exposure - more persons involved in the production or
               industrial use of the chemical, but exposure rates are low.

                    Fate Tests:  Half-life determinations in water and
                         soil, etc.
                                 Biological or chemical oxygen demand
                         (BOD, COD)

          Level III Exposure - more individuals become exposed through occu-
               pational, hobby, repair, or incidential chemical contact.

                    Fate Tests:  Biodegradation
                                 Metabolic or decomposition products
                                 Transport mechanisms

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          Level IV Exposure - use so widespread that nearly everyone is
               exposed to the chemical or use is such that exposure to it
               in small amounts becomes unavoidable (this level frequently
               is only reached after adverse findings or publicity).

                    Fate Tests:  Disposition
                                   Sewage treatment
                                   Incineration
                                   Landfill
                                 Food-chain accumulation

Although the survey by Woodard (1974) focused on toxicity test methods, it did

provide some insight into the ordering of environmental fate tests that are pre-

sently being conducted by some chemical companies.

          One category of chemicals that routinely receives environmental fate

testing is pesticides.  EPA's Pesticides Office has published proposed guidelines

for registering pesticides, as well as an Appendix VI (EPA, 1975), which pro-

vides considerable detail as to the recommended tests and methodology to be

used.  A list of the tests to be run follows:

          ENVIRONMENTAL CHEMISTRY - Appendix VI (EPA, 1975)

               Chemodynamic parameters
                    Water solubility
                    Partition coefficient
                    Dissociation constant
                    Adsorption
               Hydrolysis studies
               Photochemical studies
               Leaching studies
                    Laboratory
                    Field
               Volatilization studies
               Laboratory soil metabolism studies
               Field dissipation studies

          The protocols in Appendix VI provide clear guidelines for the environ-

mental fate testing that needs to be conducted to register a pesticide, but the

order in which the protocols should be conducted is only implied.  For example,

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the water solubility needs to be determined before the hydrolysis study so




that the concentration used in the hydrolysis study does not excee^ the water




solubility.  No correlation between the quantity of pesticide .o be used and




the amount of testing to be conducted is stated.  In fact, because the guidelines




in Appendix VI are only proposed, the tests that have to be run to register a




new pesticide may vary considerably.  The Pesticide Office presently uses an




informal procedure of advice and comment for guiding pesticide companies who




are attempting to generate environmental fate data for registration (Ney, 1977).




With chemicals reviewed by the Office of Toxic Substances, some correlation be-




tween the quantity of a chemical being used and.the amount of testing is needed.




Also, the pesticide protocols emphasize the soil medium9 which is quite reason-




able for pesticides sprayed on crops, but such emphasis may not be justified




for many of the chemicals that the Office of Toxic Substances will consider.




Thus, although the guidelines for registering pesticides provide a starting




point for environmental fate testing protocols for the Office of Toxic Substances




(OTS), they need to be modified and prioritized considerably for OTS use.




          The available documents on environmental fate testing indicate that




design of the experimental procedures frequently is on an ad hoc basis and




extremely variable.  The contrast between toxicity testing and environmental




fate testing is particularly apparent from the report by Woodard  (1974), where




such tests as acute oral LD,.  are well understood and estimates of the cost of




the tests are available (Gehring et^ al_. , 1973).  In contrast, with environmental




fate testing, little standardization is available  (although Appendix VI provides




good guidelines), and the costs are virtually unknown (see Howard e_t^ al. 9 1975




and Witherspoon at al_., 1976 for some approximations).  This lack of standardi-




zation is perhaps justified by the almost infinite ways that chemicals may be

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released to and reside in the environment.   However, the hazard involved in




unstandardized tests is that considerable amounts of money and effort may be




spent in an attempt to determine the environmental fate of a chemical, but




result in little insight into the transport and degradation processes if the




test is not well designed (for an example of this, see Howard and Saxena, 1976).




Also, the interpretation of unstandardized tests frequently varies, which makes




it difficult to compare one chemical to another.




     B.   Chlorobenzene Case Study




          Protocols for environmental fate testing of a chemical should reflect




an evaluation of all the available information including chemical marketing and




physical-chemical data.  Chemical marketing data provides insight into the




quantities of the chemical that might be released and the medium into which




the release will initially occur.  This provides guidance for the extent of




testing that is justified and the type of tests that should be undertaken.  For




example, a compound used as a chemical intermediate whose production volume is




less than 100,000 pounds probably should only receive inexpensive screening




tests, or perhaps no fate testing at all.  Depending upon the results from screening




tests  (e.g., a compound may appear to be very persistent), more testing may be




necessary.  Compounds used as solvents (probably lost to the atmosphere) should




be tested first in the vapor phase, while chemicals that are deposited in land-




fills should be tested first with soil systems.




          Physical and chemical data can be used to estimate stability in the




environment and routes of transport (bioaccumulation, evaporation, leaching, etc.).




Such estimates will be considered with the test case chemical.




          In considering the case study, information on toxicity, environmental




monitoring, and environmental fate, although available, has been ignored in order

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that the test case be more representative of an existing or new chemical for




which the Office of Toxic Substances (OTS) will be called upon to design protocols.




Most of the chemical marketing data and chemical and physical properties will be




available for all the chemicals reviewed by OTS.  Information on toxicity should




have an impact upon the degree, but not the type, of environmental fate testing




to be conducted.  Extremely toxic or carcinogenic, mutagenic, or teratogenic




chemicals should be extensively tested for environmental fate.  However, rarely




will a complete toxicologic evaluation be available and, therefore, the extent




and type of environmental fate tests should rely heavily on estimates of the




amount released to the environment and physical and chemical properties.  Also,




toxicologic evaluations would not consider hazardous degradation products which




might be formed in the environment.




          Ambient monitoring data may be used to establish protocols for existing




commercial chemicals, but will be of little use with new products.  Monitoring




should not be used as a substitute for good environmental fate testing, or visa




versa, because frequently chemicals have not been detected until after levels




causing adverse effects have been reached and considerable time may be required




to eliminate the contamination.  Also, intermedia transport  (e.g. evaporation




from soil) may provide misleading monitoring data concerning the environmental




fate of a chemical.  Thus, environmental monitoring should be used as a check




on environmental fate testing of known chemicals and as a way to identify un-




recognized contaminants which may have slipped through the pretesting procedures




(e.g. by-products from commercial processes).




          The following sections outline a procedure for devising environmental




fate testing protocols for chlorobenzene.  No attempt has been made to determine

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the exact extent of testing that is required, since such details need to be

considered relative to other chemicals and in terms of cost-benefit.  However,

ordering of the tests has been attempted and interrelationships between the

tests have been examined.

          Step 1 - Review Available Information

               Step 1 a - Consideration of Chemical Marketing - Environmental
                          Release Data

                    Table 1 summarizes the chemical marketing information on

chlorobenzene.  The chemical is mostly used as a chemical intermediate, which

should reduce the amount of the chemical that is released to the environment.
         Table 1.  Chemical Marketing Data for Chlorobenzene (SRI, 1975)
Chlorobenzene (Millions of Pounds)
Capacity
Production
Imports
Exports
Consumption




Phenol Production
Chloronitrobenzenes Production
DDT Production
All Other3
655
403.5
-
-
110
130
20
144
(1974)
(1972)


(1972)
(1972)
(1972)
(1972)
                                         Total
404    (1972)
       Trade literature estimates that at least 50 million pounds per year
       of chlorobenzene are used as solvents.

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However, significant quantities (50 million pounds annually) appear to be used




for solvent purposes, which might result in significant release to water systems




(if the solvent is used in contact with water) or the atmosphere (during use or




distillation recovery).  Presumably, more detailed marketing and perhaps environ-




mental release information would be available to the Office of Toxic Substances.




However, the available information suggests that environmental fate testing in




simulated atmospheric systems and in water should be considered.  If some of the




solvent applications result in disposal in landfills, soil systems may also be




considered.




               Tests such as Warburg or model activated sludge systems indicate




the treatability of a chemical in an activated sludge water treatment plant.




Such tests provide indications of environmental release when a chemical is




treated in a biological water treatment plant, but provide only limited in-




formation on biodegradability in natural water systems.  Thus, such tests should




not be considered environmental fate tests.




               Step 1 b - Evaluations of Physical and Chemical Properties




                    Chlorobenzene is a liquid at ambient temperature with a




relatively high vapor pressure (9 mm Hg at 20°C), intermediate partition co-




efficient, and low water solubility (360 ppm).  The ultraviolet absorption




spectrum in isooctane indicates only very slight absorption above 280 nm




(A    = 271 nm).  However, correlations between absorption spectra and photo-




degradation are poorly understood.  Direct absorption of energy is not re-




quired for photolysis  (e.g. sensitizer reactions).  Other physical properties




of chlorobenzene are listed in Table 2, but they have little importance to




environmental fate.  The chemical structure of .chlorobenzene (chlorinated

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       Table 2.   Physical Properties of Chlorobenzene
                 (Hardie, 1964)
        °C
        °C
                    (octanol/water)
melting point,
boiling point,
steam distillation point,
log partition coefficient'
water solubility'5

 U 0°C
  10°C
  16.5°C

•S
  15°C
  20°C
surface tension, dyn/cm
  15°C
  20°C
specific heat,  C   (T  = °K)
critical temperature,  °C
critical pressure, mm Hg
critical density
explosive  limits in air,  vol  %
  lower, 100°C
  upper, 150°C
flash point,  °C
dielectric constant
  20°C
  70°C
. 106°C
  at bp
dipole moment  (dil. benzene soln.),  esu
heat of combustion  (at constant  pressure),  kcal/g-mole
latent heat of  vaporization,  keal/g-mole
viscosity, cP
  15°C
  30°C
  60°C
 120°C
 130°C
vapor pressure, mm Hg
   0°C
  20°C
  40°C
  60°C
  80°C
 100°C
 120°C
-45.21
131.5
90
2.88
360 ppm

1.1293
1.1167
1.1058

1.52748
1.52460

33.86
33.28
0.2988 + 0.00074 T
359.2
33962
0.3654

1.8
9.6
24

5.6493
4.886
4.435
4.144
1.58 x 10
763.88
8.73

0.844
0.711
0.512
0.313
0.292

3
9
26
65
144
292
543
                                                            18
Leo et_ al., 1971
Metcalf and Lu, 1973
                                10

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aromatic) suggests that it would be fairly stable in the environment by analogy



with other well known contaminants (DDT, PCB's, hexachlorobenzene).  Such



structure-environmental fate correlations should be used whenever possible



(see review in Howard et_ al., 1975).



               The physical properties can be used to estimate the rates of



transport of a chemical that is released to the environment.  These calculations



for chlorobenzene are summarized in Table 3, where calculated values for benzene



and DDT are provided for comparison.  The calculations indicate that chloro-



benzene has a low potential for bioaccumulation and should evaporate relatively



fast from water (C  _/C    =  <100 is defined as a chemical that is rapidly lost from
                  ttrtW  ' C&1.L


water surfaces).  The calculated values should be used with caution since they



are only estimates that may give misleading impressions.  For example, although



the calculated ecological magnification for chlorobenzene is 9, the experimental



value is 645 (Metcalf and Lu, 1973), which is comparable to the experimental



value for tetrachlorodibenzodioxin (calc. = 25,000; exper. = 822) and hexachloro-



benzene  (calc. = 20,000; exper. = 343).



               Nevertheless, the physical properties can provide considerable



insight  into the type of testing that should be considered.  With chlorobenzene



in water, it appears that a major loss mechanism may be volatilization.  Whether



degradation processes in water can compete will have to be determined experi-



mentally.  The calculations also emphasize the importance that atmospheric processes



are likely to play in the environmental fate of chlorobenzene.



               Step 1 c - Review Literature on Chemical Reactivities and

                          Product Formation



                    Literature searches are considerably cheaper than experi-



mental work, and, therefore, the former should be undertaken before any





                                     11

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              Table 3.  Calculations of Bioaccumulation and Evaporation Rates from Physical Properties
                Bioconcentration Factor
                    Calculated From
                 Partition Coefficient
                 Ecological Magnification
                     Calculated From,
                    Water Solubility
    Half-life (Hours)
   of Evaporation From
  Water Calculated From
  Vapor Pressure, Water
Solubility, and Molecular
         Weight0
  Ratio CH20/Cair

  Calculated From
  Vapor Pressure
and Water Solubility'
Chlorobenzene
46
            5.8
           6.12
DDT (for comparison)
Benzene (for
comparison)
650
19
29,300
4
73.9 326
4.81 4.5
  ? Neely £t al. (1974)
    Metcalf and Lu (1973)
  , Mackay and Leinonen (1975)
    Appendix VI Guidelines for Registering Pesticides

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experimental work begins.  Information may already be available that would




eliminate the necessity for some or all (highly unlikely) of the environmental




fate tests.  Also, examination of previous studies will provide insight into




analytical methods that might be used and breakdown products that might be




formed.




                    A preliminary examination of available information on




chlorobenzene indicates that its degradation in aerated lagoons (Garrison, 1969)




and activated sludge has been examined and its photolysis (wavelength less than




253 nm - not representative of sunlight) in the gas phase studied (Ichimura et




al. , 1973).  Also, Gibson et^ al. (1968) found that chlorobenzene is converted




to 3-chlorocatechol when it was incubated with Pseudomonas putida grown with




toluene as a sole source of carbon; this information will assist in the identi-




fication of degradation products.  In addition, as previously mentioned, the




ecological magnification in a model ecosystem has been determined (Metcalf and




Lu, 1973).




          Step 2 - Development of Any Missing Physical Parameters




               After reviewing the available information, there may be some




missing physical parameters (e.g., water solubility, partition coefficient,




vapor pressure, dissociation constant).  The partition coefficient may be ob-




tained from the tabulation of Leo et^ aJL. (1971), calculated using additivity




principals (Hansch et al., 1972), or measured experimentally (see Pesticide




Registration Guidelines Appendix VI for methodology).  The other physical




properties will have to be measured experimentally  (see Appendix VI).  With




chlorobenzene, a dissociation constant  is unnecessary since chlorobenzene does




not dissociate.  The water solubility, vapor pressure, and partition coefficient




are available.






                                      13

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               These physical properties should be measured before experiments

on degradation and transport are begun so they can be used in designing the

experimental test conditions.

          Step 3 - Screening Tests

               Tests can be divided into three categories by analytical method:

(1) tests that require no analytical method for the chemical (e.g. BOD, Warburg -

both measure consumed oxygen) (this lack of analytical method only applies to

degradation tests, not transport studies) (2) tests that require specific analy-

tical methods for the chemical, and (3) tests that use radiolabelled material.

The use of radiolabelled chemicals for environmental fate testing is the most

desirable because it allows for a mass balance of the test chemical and products,

is very sensitive, and combined with thin layer chromatography can provide in-

sight into the breakdown products.  Chemical analytical methods allow the in-

vestigator to follow the disappearance of the parent compound and, if he knows

what products to expect, to develop analytical methods for the degradation

products.  In some instances, radiolabelled parent compound may not be avail-

able or an analytical method needs to be developed for the degradation products,

and the cost of synthesis or analytical method development are not justified.

In these instances, a variety of screening tests may be considered.  Examples

of such tests are:

               BOD
               Warburg
               River die-away
               2-day Hydrolysis and photolysis studies under acidic, neutral,
                    and basic conditions (see Wolfe et al., 1976)
               Soil adsorption or TLC studies
               Rapid evaporation studies from water

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Rapid screening tests such as these usually measure the relative increase in



oxygen uptake or the disappearance or transport of the test chemical.  Long-



path infrared cells, which have been used to study atmospheric photooxidation,



might also be considered in this category since an analytical method does not



need to be developed (infrared absorption).  However, the equipment is so ex-



pensive and complicated that it should not be considered a screening test.



               Screening tests have the advantage that they are rapid and



inexpensive.  However, they provide very limited information on the environmental



fate of a chemical.  With BOD and Warburg, the parameter being measured, oxygen



uptake, is only an indirect indication of degradation.  The results are diffi-



cult to interpret unless extremes, such as no oxygen uptake or 100% of the theore-



tical oxygen demand are found, which is rarely the case, and the conditions of the



Warburg test are more similar to an activated sewage treatment plant than to



natural conditions.  The die-away and hydrolysis tests only determine the rate



of disappearance of the test compound (good indication of persistence), but pro-



vide little insight into the degradation products, which is equally important.



               With chlorobenzene, if screening tests are the only ones justi-



fiable, a BOD and river die-away test probably should be run, and perhaps a



rapid photolysis study in hexane (provide preliminary indications of the atmo-



spheric photooxidation).  Since chlorobenzene is very stable in water, hydrolysis



studies do not seem justified.  The Warburg test indicates treatability rather



than environmental fate and, therefore, should not be undertaken unless it is



anticipated that sizable quantities of chlorobenzene will pass through an acti-



vated sludge treatment plant.  Because of the limited information provided from



the screening tests, it seems reasonable to consider avoiding these tests if


                                                          14
more detailed studies are anticipated.  Also, 100 yCi of C   uniformly labelled




                                      15

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chlorobenzene is available for about $80, so it would seem more reasonable to

conduct any screening tests with radiolabelled material (BOD and Warburg are

exceptions).

          Step 4 - Intermediate Tests

               Tests in this category, with the exception of atmospheric photo-

oxidation systems, are generally characterized by the use of radiolabelled material.

The difference between this category and the following category of more detailed

studies is that any major (> 10% - Appendix VI Pesticide Guidelines) degradation

products may be characterized  (e.g., TLC mobility, gas chromatography retention

time, UV absorbance on TLC (+ or -), radioactive content, or possible TLC spray

reactions - Pesticide Guidelines Appendix VI), but not chemically identified.

Rigorous and complete chemical identification is extremely time consuming and

expensive, although the use of GC-MS systems has considerably simplified the

process.  Environmental fate tests that fall into an intermediate category in-

clude the following:

          Atmospheric
               Long-path infrared cells
               Plastic containers
               Glass flask reactors

          Water
               Hydrolysis studies (various pH and temperature - determine the
                    kinetics)
               Photolysis with simulated sunlight in various matrices (determine
                    kinetics - use sensitizers and natural water)
               Die-away tests with radiolabelled material (sea, lake, river
                    water from various sources to provide a wide spectrum of
                    microbes, pH, pollution, organic content, etc. - include
                    with and without sediment, sterile control, aerobic and
                    anaerobic conditions)
               Shake culture tests
               Shake culture using pure cultures
               Model sewage treatment systems
                                      16

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          Soil
               Soils incubated with test chemical (aerobic,  flooded, anaerobic
                    conditions, soils suspended in water)
               Pure cultures isolated from soil
               Greenhouse studies

          Transport
               Volatility - from water (Billing et^ al.,  1975)
               Bioaccumulation and biomagnification - terrestrial-aquatic or
                    aquatic model ecosystems (Metcalf method, Isensee method)
               Uptake by individual biota
               Desorption from organisms

The above list illustrates the considerable number of laboratory tests that may

be undertaken to determine the environmental fate of a chemical.  Not included

are the many variations of the above tests that are possible (see Howard et al.,

1975; Witherspoon je£ al., 1976).  Some techniques, such as the use of pure culture,

might more appropriately be used to determine the pathways of degradation (next

category).  Results using pure culture, although they have been used to indicate

persistence (ability to use a chemical as a carbon and energy source), are diffi-

cult to relate to the rates of degradation that might take place in nature.

               Without considering a particular compound, it is extremely diffi-

cult to prioritize the above tests.  With chlorobenzene, it would appear to be

important to determine the rate and products of atmospheric photooxidation, the

rate of evaporation from water, and the rate and products of degradation (chemical

and biological) in water.  If the rate of degradation in water is slow compared

to the rate of evaporation, studies of the atmospheric photooxidation will be

considerably increased in importance.  Products of atmospheric photooxidation

(e.g. perhaps chlorophenols) are probably less volatile, suggesting that they

should be studied in water or soil systems, although considerable insight into

the behavior of chlorophenols in soil and water is already available.  Long-path

infrared cells for atmospheric tests have the advantage  that no analytical method
                                      17

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needs to be developed.  However, the equipment used for atmospheric studies is

not available in many laboratories, so plastic or glass containers may be pre-

ferred.  The analytical method used, the scheduling of tests, etc. should be

left to individual researchers.

          Step 5 - Detailed Laboratory and Field Tests

               Studies in this category include techniques oriented at chemical

identification of intermediates, determination of pathways of degradation, tests

that examine in detail the effect of various conditions on reaction rates (e.g. the

effect of NO  concentration on photooxidation rates - usually conducted in smog
            X

chambers), and field  tests.  In general, studies in this category are very

expensive and time consuming.  Detailed laboratory or field tests include:

          Air
               Smog chamber
               Release and monitoring studies

          Water
               Die-away tests in treated ponds, lakes, streams
               Treatability of a chemical in a commercial activated sludge
                    treatment plant
               Pure culture techniques to determine pathways of degradation

          Soil
               Field  plots - monitoring
               Landfills - monitoring gases and leachate
               Pure culture techniques to determine pathways of degradation

          Transport
               Field  studies followed by monitoring biota, soil, water, etc.


Field  studies suffer  from low reproducibility because of the variable test con-

ditions, but provide  the only results where natural conditions are used.  However,

because radiolabelled material cannot be used, rarely are degradation products

examined, although they may be analyzed if the field test follows the inter-

mediate test, since the intermediate test may provide indications of the degra-

dation products that  will be formed.  It seems unlikely that techniques in this


                                      18

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category should be used except for chemicals that are released to the environment




in very large quantities (e.g. pesticides - see Appendix VI,  detergents,  etc.).




If justified from release estimates, chlorobenzene should be  tested in a smog




chamber and perhaps in a die-away test in a pond or lake.  Stable metabolites, which




may have been determined from the intermediate tests, should  also be monitored.
                                     19

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III. CONCLUSIONS AND RECOMMENDATIONS




     Establishing protocols for environmental fate testing of chemicals that




are of interest to the Office of Toxic Substances has been divided into five




steps:




          Step 1    Review and evaluation of available information




          Step 2    Development of any missing physical parameters




          Step 3    Screening tests




          Step 4    Intermediate tests




          Step 5    Detailed laboratory or field tests




     This is only a preliminary result which may need considerable revision




before implementation of test protocols.  The tests recommended for one test




case chemical, chlorobenzene, are considered based upon commercial considera-




tions and chemical and physical properties.  More experience is needed with a




greater variety of chemical compounds.  The level of testing required should




be based upon the quantity of the chemical being released to the environment,




toxicity (if known), and a cost/benefit analysis.
                                     20

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                                  REFERENCES
Dilling, W.L., Tefertiller, N.B. and Kallos, G.J. (1975), "Evaporation Rates
     and Reactivities of Methylene Chloride, Chloroform, 1,1,1-Trichloroethane,
     Trichloroethylene, Tetrachloroethylene, and Other Chlorinated Compounds in
     Dilute Aqueous Solutions," Environ. Sci. Technol. 9/9):833-8.

Environmental Protection Agency (1975), "Guidelines for Registering Pesticides
     in the United States," Fed. Regist. 40(123):26878-26895.

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     Div. Water, Air Waste Chem., Gen. Pap. j[(2):51-9.

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     Fd. Cosmet. Toxicol. 11:1097-1110.

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     Degradation of Aromatic Hydrocarbons by Microorganisms. II. Metabolism of
     Halogenated Aromatic Hydrocarbons," Biochem. _7(11):3795-802.

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     of Partition Coefficients," J. Org. Chem. 37;3090.

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     2nd Ed., Jj:253-267.

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     Benzidine and Other Carcinogenic  Compounds," EPA 560/5-76-005, Prepared
     for the Office of Toxic Substances, EPA, Washington, D.C.

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     Degradation of Chemical Substances in the Environment," EPA-560/5-75-006,
     U.S. Nat. Tech. Inform. Serv. PB  243 825/7WP.

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     J. Chem. Phys. _58_(1):288-92.

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     Uses," Chem. Rev. 21(6)=525-616.

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     Contaminants from Water Bodies to Atmosphere," Environ. Sci. Technol.,
     2(13):1178-1180.

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     Fate of Key Industrial Pollutants and Pesticides in a Model Ecosystem,"
     U.S. Nat. Tech. Inform. Serv. PB  225-479.
                                      21

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Neely, W.B., Branson, D.R. and Blau, G.E. (1974), "Partition Coefficient to
     Measure Bioconcentration Potential of Organic Chemicals in Fish," Environ.
     Sci. Technol. £(13):1113-1115.

Ney, R., Personal communication, Pesticides Office, EPA.

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     Chemical Economics Handbook, Menlo Park, California.

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     Trabalka, J.R.  (1976), "State-of-the-Art and Proposed Testing for Environ-
     mental Transport of Toxic Substances," ORNL/EPA-1, Environmental Sciences
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     EPA-560/5-75-002, for the Office of Toxic Substances, EPA, Washington, D.C.

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v    "Chemical and Photochemical Transformation of Selected Pesticides in
     Aquatic Systems," Environmental Processes Branch, Environmental Research
     Laboratory, Athens, Georgia.
                                      22

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                                   TECHNICAL REPORT DATA
                            (Please read tauntctwns on the reverse before completing)
1. REPORT NO.
     EPA-560/5-77-001
                              2.
                                                           3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
  .  Prioritized Guidelines for Environmental  Fate
     Testing of One Halogenated Hydrocarbon:
     Chlorobenzene
             5. REPORT DATE
              January 1977
             6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
     Philip H. Howard
                                                            8. PERFORMING ORGANIZATION REPORT NO
               TR 76-591
9. PERFORMING ORGANIZATION NAME AND ADDRESS
     Center for Chemical Hazard Assessment
     Syracuse Research Corporation
     Merrill Lane, University Heights
     Syracuse, New York   13210
                                                            10, PROGRAM ELEMENT NO.
             11. CONTRACT/GRANT NO.
               EPA 68-01-2679
12. SPONSORING AGENCY NAME AND ADDRESS
     Office of Toxic  Substances
     U.S. Environmental  Protection Agency
     Washington, D.C.    20460
             13. TYPE OF REPORT AND PERIOD COVERED
               Final Technical Report
             14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
          Protocols  for environmental fate  testing of chemicals  that  are of interest
     to the Office of  Toxic Substances have been divided into five  levels of increasing
     complexity and  cost:  (1) review and evaluation of available information, (2)
     development of  any missing physical parameters, (3) screening  tests, (4) inter-
     mediate tests,  and (5) detailed laboratory or field tests.   Chlorobenzene is
     used as an example to determine the types of tests to be run.  The level of
     testing required  should be based upon  the quantity of the chemical being re-
     leased to the environment, toxicity (if known), and a cost/benefit analysis.
17.
                                KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
     Environmental  fate tests
     Persistences
     Biodegradation
     Hydrolysis
     Chlorobenzene
     Photodegradation
                                               b.IDENTIFIERS/OPEN ENDED TERMS
                           c.  COS AT I Held/Group
18. DISTRIBUTION STATEMENT
Document is available to public through  the
National Technical  Information Service,
Springfield, Virginia   22151
19. SECURITY CLASS (Tills Report)
21. NO. OF PACib.S
      22
20. SECURITY CLASS (Thispage)
                           22. PRICE
EPA Form 2220-1 (9-73)
                                              23

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