Draft
                                                                        10/30/85
             AMBIENT AQUATIC LIFE WATER QUALITY CRITERIA FOR

                               CHLORPYRIFOS
NOTE:  This draft contains only freshwater data.  The saltwater data
       will be incorporated later.  The freshwater CCC is likely
       to change when the saltwater data are incorporated.
                   U.S. ENVIRONMENTAL PROTECTION AGENCY
                    OFFICE OF RESEARCH AND DEVELOPMENT
                    ENVIRONMENTAL RESEARCH LABORATORIES
                            DULUTH, MINNESOTA
                        NARRAGANSETT, RHODE ISLAND

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                                 NOTICES
This document has been reviewed by the Criteria and Standards Division,
Office of Water Regulations and Standards, U.S. Environmental Protection
Agency, and approved for publication.

Mention of trade names or commercial products does not constitute
endorsement or recommendation for use.

This document is available to the public through the National Technical
Information Service (NTIS), 5285 Port Royal Road, Springfield, VA 22161.

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                                 FOREWORD
     Section 304(a)(l) of the Clean Water Act of 1977 (P.L. 95-217)
requires the Administrator of the Environmental Protection Agency to
publish criteria for water quality accurately reflecting the latest
scientific knowledge on the kind and extent of all identifiable effects
on health and welfare that nay be expected from the presence of pollutants
in any body of water, including ground water.  This document is a revision
of proposed criteria based upon a consideration of comments received from
other Federal agencies, State agencies, special interest groups, and
individual scientists.  The criteria contained in this document replace
any previously published EPA aquatic life criteria.

     The term "water quality criteria" is used in two sections of the
Clean Water Act, section 304(a)(l) and section 303(c)(2).  The term has a
different program impact in each section.  In section 304, the term
represents a non-regulatory, scientific assessment of ecological effects.
The criteria presented in this publication are such scientific assessments.
If water quality criteria associated with specific stream uses are adopted
by a State as water quality standards under section 303, they become
enforceable maximum acceptable concentrations of a pollutant in ambient waters
within that State.  The water quality criteria adopted in the State water
quality standards could have the same numerical values as the criteria
developed under section 304.  However, in many situations States may want
to adjust water quality criteria developed under section 304 to reflect
local environmental conditions and human exposure patterns before incorporation
into water quality standards.  It is not until their adoption as part of
the State water quality standards that the criteria become regulatory.

     Guidelines to assist the States in the modification of criteria
presented in this document, in the development of water quality standards.
and in other water-related programs of this Agency, have been developed
by EPA.
                                    Director
                                    Office of Water Regulations and Standards
                                   111

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                             ACKNOWLEDGMENTS
Loren J. Larson
(freshwater author)
University of Wisconsin-Superior
Superior, Wisconsin
                           Jeff Hyland
                           (saltwater author)
                           Environmental Research Laboratory
                           Narragansett, Rhode Island
Charles E. Stephan
(document coordinator)
Environmental Research Laboratory
Duluth, Minnesota
                           David J. Hansen
                           (saltwater coordinator)
                           Environmental Research Laboratory
                           Narragansett, Rhode Island
Clerical Support:
Terry L. Highland
Shelley A. Heintz

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                                 CONTENTS
                                                                        Page

Foreword	    iii

Acknowledgments   	     iv

Tables	     vi


Introduction  	      1

Acute Toxicity to Aquatic Animals   	

Chronic Toxicity to Aquatic Animals   	

Bioaccutnulation	

Other Data 	

Unused Data   	

Summary   	

National Criteria  	


References	

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                                  TABLES






1.  Acute Toxicity of Chlorpyrifos to Aquatic Animals




2.  Chronic Toxicity of Chlorpyrifos To Aquatic Animals




3.  Ranked Genus Hean Acute Values with Species Mean Acute-Chronic




    Ratios




4.  Toxicity of Chlorpyrifos to Aquatic Plants




5.  Bioaccumulation of Chlorpyrifos by Aquatic Organisms




6.  Other Data on Effects of Chlorpyrifos on Aquatic Organisms  ..
                                    VI

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Introduction*

     Chlorpyrifos is one of several organophosphorus compounds developed in

the 1960s to replace persistent organochlorine pesticides.  It has been

widely used as a broad spectrum insecticide for agricultural and domestic

pests.  It is directly applied to aquatic environments in mosquito, midge.

and blackfly abatement projects.

     Chlorpyrifos is produced by the Dow Chemical Company (Midland, MI,

USA) under the trade names Dursban® and Lorsban®.  Gray (1965) and Marshall

and Roberts (1978) have reviewed its composition and physical and chemical

properties.  Its commercial formulations for pesticide application include

emulsifiable concentrates (EC), wettable powders (WP), granules, and

controlled-release polymers.  The resulting concentration of Chlorpyrifos

in water and its persistence varies from one formulation to another.  In

general, emulsifiable concentrates and wettable powders produce a large

pulse in Chlorpyrifos concentrations immediately after application.

Water concentrations rapidly decline as Chlorpyrifos is taken up by the

several natural sinks (discussed later].  Granules and controlled-release

formulations do not produce as prominent an immediate pulse in water, but low.

yet significant concentrations remain in the environment for a longer

duration.

     The percentage of active ingredient in the formulations can vary

considerably, both between formulations and within a single formulation
* An understanding of the "Guidelines for Deriving Numerical National Water
  Quality Criteria for the Protection of Aquatic Organisms and Their Uses"
  (Stephan et al. 1985). hereafter referred to as the Guidelines, is necessary
  in order to understand the following text, tables, and calculations.

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over  time as manufacturers' specifications change.  This results in a




large percentage of often unspecified ingredients, many used as carriers,




in commercial  formulations.  These ingredients are considered inert,




although technical grade chlorpyrifos has generally been found to be more




toxic than an  equal quantity of active ingredient in formulation (Darwazeh




and Mulla 1974; Jarvinen and Tanner 1982; Siefert et al. 1984).  For this




reason, the effect of the inert ingredients can not be discounted.  Under




normal application conditions, the commercial formulations are often




combined with  petroleum products, such as No. 2 diesel oil or kerosene,




to increase the rate of dispersal.  Solvents have been shown to have




significant toxic effects separate from chlorpyrifos (Wallace et al.




1973: Jamnback and Frempong-Boadu 1966).




     Numerical water quality criteria are derived herein solely for the




chemical chlorpyrifos.  Although some data obtained from studies using




formulations are discussed, only data derived from toxicity tests utilizing




an adequately high-quality chlorpyrifos are used in deriving criteria.




     The toxic effect of chlorpyrifos is the result of metabolic conversion




to its oxygen analogue, chlorpyrifos-oxon, and its subsequent inhibitive




interaction with various enzyme systems (e.g., cholinesterases, carboxylases,




acetylcholinesterases, mitochondrial oxidative phosphorylation).  Its




activity with acetylcholinesterase (AChE) is generally accepted to be its




most critical toxic effect.  AChE inhibition results in accumulation of




the neurotransmitter, acetylcholine, in synapes, disrupting normal neural




transmission.  Although in fish even substantial reductions in brain AChE




activity have not always been fatal, the effect of this condition on




normal activity (e.g., feeding, reproduction, predator-prey relationships,




etc.) in nature is not known.

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     Although less persistent than organochlorine compounds, chlorpyrifos




is very immobile when applied to most terrestrial environments.  Because




of its affinity to organic soils, little to no leaching occurs.  In lieu




of direct application to aquatic environments, chlorpyrifos can enter




through spray drift from adjacent agricultural areas or sorbed to entrained




particles resulting from erosion of treated areas.




     Once chlorpyrifos enters an aquatic system, it appears to be rapidly




sorbed to suspended organics and sediments, although some is removed by




volatilization and degradation.  Its penetration into the sediment appears




to be shallow, most occurring in the upper several milimeters.  The




equilibrium between sediment, suspended organics and the water is poorly




understood.  Chlorpyrifos residues in natural sediments and water samples




have been reported by Braun and Frank (1980), Rawn et al. (1978), Winterlin




et al. (1968), Nelson et al. (1973). Hughes et al. (1980), Hughes (1977),




Hurlbert et al.  (1970), Siefert et al. (1984), and Macalady and Wolfe (1985).




Evans (1977) reported significant chlorpyrifos concentrations, still




toxic to mosquito larvae, one year after application of a slow-release




polymer formulation to a natural pond.




     The use of slow-release polymers will probably result in differential




exposure, both in concentration and duration, between benthic and pelagic




organisms.  Organisms inhabiting the water-sediment interface have the




potential to receive larger and more sustained concentrations than free-swimming




organisms.




     Chlorpyrifos, although highly toxic, is rapidly metabolized by fish,




3,5 .6-trichloro-2-pyridinol being the major product (Marshall and Roberts,




1978).  Residues in fishes are generally low for this reason.  Several




studies have reported residues of chlorpyrifos in wild fishes (Clark et

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al.  1984, Mulla et al.  1973), and cultured or experimental  fishes  (Macek




et al. 1972, Winterlin  et al. 1968, Siefert et al.  1984).




     All concentrations herein are expressed as chlorpyrifos, not  as the




material tested.  Whenever adequately justified, a  national criterion may




be replaced by a site-specific criterion (U.S. EPA  1983a) , which may




include not only site-specific criterion concentrations (U.S. EPA  1983b).




but  also site-specific  durations of averaging periods and site-specific




frequencies of allowed  exceedences (U.S. EPA 1985).  The latest literature




search for information  for this document was conducted in February, 1985;




some newer information was also used.






Acute Toxicity to Aquatic Animals




     Most of the available data on the acute toxicity of chlorpyrifos to




freshwater animals is from the U.S. Fish and Wildlife Service Laboratory




in Columbia. MO or the U.S. EPA Laboratory in Duluth, MN.  The data from




the Fish and Wildlife Service are contained in publications by Johnson




and Finley (1980), Macek et al. (1969), Sanders (1969, 1972) and Sanders




and Cope (1968) and include values for five invertebrates and five fishes.




The data from the EPA were published by Holcombe et al. (1982), Jarvinetr,




and Tanner (1982), Phipps and Holcombe (1985a, b),  and Siefert et  al.




(1984), and also include values for five invertebrates and five fishes^.




The only other acute value is from a test with a beetle by Federle and"




Collins (1976).




     Within arthropods  and fishes separately, and within all species combined,




there appears to be an inverse relationship between size and sensitivity;




to chlorpyrifos.  The snail, Aplexa hypnorum, is the only species  that ik




not either an arthropod or a fish for which an acute value is available:-..

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     The Species Mean Acute Values (Table  1) were used  to calculate Genus




Mean Acute Values  (Table 3).  Although values are available  for  13 genera,




none is a planktonic crustacean.  The most sensitive genus,  Gammarus. is




more than 4,300 times more sensitive than  the most resistant genera.




Aplexa, Carassius, and  Ictalurus, but the  four most sensitive genera are




within a factor of 4. and all are invertebrates.  Mean  acute values are




available for more than one species in each of two genera, and the range




of Species Mean Acute Values within each genus is less  than  a factor of




3.  The freshwater Final Acute Value of 0.1669 pg/L was calculated from




the Genus Mean Acute Values (Table 3) using the procedure described in




the Guidelines.  Criterion Maximum Concentration is 0.08345  wg/L, which is




below the normal detection limits.






Chronic Toxicity to Aquatic Animals




     Available data on the chronic toxicity of chlorpyrifos  contains




information on a single test species, the  fathead minnow.  Chronic values




for technical grade and encapsulated material were 2.26 ;jg/L and 3.25




iJg/L, respectively, in early life stage tests (Jarvinen and  Tanner, 1982).




Growth over the 32-day tesp was the most sensitive parameter using




technical grade chlorpyrifos whereas with  the encapsulated formulation,




growth and survival were equally sensitive.  In a life  cycle test with




the same species (Jarvinen et al. 1983) unacceptable effects occurred at




0.41 »Jg/L in the first generation and at 0.12 ^ig/L in the second generation,




showing rather poor agreement between the  early life-stage test and the




life-cycle test.  Based on these results the acute-chronic ratio for



chlorpyrifos is greater than 1,417 with the fathead minnow.  Jarvinen et




al. (1983) also estimated the chronic effect of chlorpyrifos on the




viable biomass recruitment of a natural population of the fathead minnow.

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Requirements  for an adequate data set for the calculation of Final Chronic




Value as prescribed in the Guidelines are not met.






Toxicity to Aquatic Plants




     Several  field studies have examined the effects of chlorpyrifos on




phytoplankton under more or less natural conditions (Brown et al. 1976;




Butcher et al.  1975,  1977: Hughes et al. 1980: Hurlbert 1969: Hurlbert et




al . 1972; Papst and Boyer 1980).  All used an emulsifiable concentrate




formulation of  chlorpyrifos which makes them inappropriate for inclusion




in Table 4, but the general trends identified are germaine to a discussion




of the effects  of chlorpyrifos under natural conditions.  With the




exception of Brown et al. (1976), all observed increased phytoplankton




numbers after pesticide application.  This change is generally accepted




not to be a direct effect of chlorpyrifos, but rather a result of changes




in the herbivore-algal relationship caused by large reductions in




zooplankton populations.  Reduced macrozooplankton numbers releases phytoplankton




community from herbivory.  Papst and Boyer (1980) attempted to substantiate




this hypothesis experimentally by following concentrations of pheopigments,




the major chlorophyll a degradation product of herbivory.. after chlorpyrifos




application.  Although this study did identify reductions in pheopigments,




the effect was delayed.  They observed rapid increases in microzooplankton




(e.g., rotifers) numbers immediately after chlorpyrifos application,




presumably due  to reduced competition with macrozooplankton.  Other studies




have also observed an increase in microzooplankton after chlorpyrifos




treatment (Hughes 1977; Hurlbert et al. 1970, 1972; Siefert et al. 1984).




Although increased phytoplankton numbers can be explained by release from




herbivory, another possible factor may be increased phosphate concentration




directly from the decomposition of chlorpyrifos and from the decomposition




of intoxified organisms (Butcher et al. 1977).




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Bioaccumulation




     Although chlorpyrifos  is hydrophobia, which would suggest its




accumulation in tissues, this is offset by its rapid metabolism (Kenaga




and Goring 1980; Marshall and Roberts 1978),  In the fathead minnow, an




average BAF at 60 days is 1673 (Jarvinen et al. 1983).  Although this




study used an encapsulated  formulation, chlorpyrifos test concentrations




were orepared separate from the test chamber.  In a review, Kenaga and




Goring (1980) cite results  of an unpublished study reporting a bioconcentration




factor in an unnamed fish of 450.




     No U.S. FDA Action Level has been set for chlorpyrifos, therefore no




Final Residue Value could be derived.







Other Data




     Data in Table 6 include investigations utilizing technical grade




chlorpyrifos. unless noted otherwise.  Many were inadequate in duration




or tested associated effects of chlorpyrifos toxicity.  Because of its




use as a biological control agent in mosquito abatement programs, the




mosquitofish has been widely studied to determine the effects of chlorpyrifos




applications on its survival and effectiveness as a mosquito larvae




predator.  Ransen et al. (1972) reported an LC50 of 4000 >jg/L for this




fish at 24 hr.  At 36 hr. LC50 of 215-230 pg/L was reported (Ferguson et




al. 1966), and at 72 hr. the LC50 was 0.19-0.22 >jg/L (Ahmed and Washino




1977).  After * 24 hr. exposure to 5.0 *Jg/L, Johnson (1978a) observed a




decreased thermal tolerance in mosquitofish.  Hansen et al. (1972) reported




an avoidance of chlorpyrifos when mosquitofish were given a choice between




clean water and a dosage of 100 ,jg/L in laboratory experiments.  The




authors noted that this result did not prove that avoidance of chlorpyrifos




occurs in nature.  The green sunfish was reported to have a 36-hr LC50





                                    7

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of  22.5-37.5ug/L (Ferguson et al. 1966).  At the same exposure duration,




the LC50 for the golden shiner was 35.0-45.0 pg/L.  For rainbow trout,




the 96 hr. LC50s at 1.6*, 7.2", and 12.7° C were 51., 15., and 7.1 yg/L,




respectively (Macek et al. 1969).  Increased toxicity of chlorpyrifos




with increased temperature was thought to be the result of increased




metabolism producing lower DO levels and higher metabolic wastes, or




increased enzyme activity converting chlorpyrifos to its more toxic form,




chlorpyrifos-oxon.  In a 24-hr, exposure to 100 ug/L, atlantic salmon had




a 4* C lower temperature preference (Peterson 1976).  Whether the preference




for a lower, presumibly less toxic temperature regimen was of any survival




benefit in nature is not known.




     Because of the widespread use of chlorpyrifos as a mosquito larvicide,




many toxicity studies have used various species of mosquito larvae as




test organisms.  Unfortunately, many studies have followed guidelines set




forth by the World Health Organization on testing of pesticides.  These




guidelines prescribe a 24-hr duration, making result unusable for




derivation of numerical water quality criteria.




     As would be expected, chlorpyrifos is highly toxic to mosquitos.




Rettich (1977) reportd 24 hr. LCSO's of 0.5 to 3.5 ;jg/L for 4th instars




of 6 species of the genus Aedes.  For A. aegypti, a species not tested by




Rettich, Saleh et al. (1981) cited 24 hr. LCSOs of 0.0011 and 0.0014




;jg/L, for 2nd and 4th instars, respectively.  Minimum lethal time (MLT)




for this species at 10 Mg/L is 18 hrs. (Verma and Rahman 1984).  Reports




of 24 hr. LC50s for 4.th instars of various Culex species range from 0.41




pg/L to 2.0 pg/L (Ahmed 1.977; Kelson et al. 1979; Rettich 1977).  For £.




pipiens, Saleh et al. (1981) found a 24-hr. LC50 of 0.0052 ,Jg/L.

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     Use of chlorpyrifos as & pesticide in controlling noxious midge




populations has been documented (Ali and Mulla 1978a. 1980; Mulla and




Khasawinah 1969; Mulla et al. 1971; Thompson et al. 1970).  LCSOs at 24




hr. for various midges generally range from 0.5 Mg/L to 40 Mg/L (Ali and




Mulla 1978a. 1980; Mulla and Khasawineh 1969) although a value of 1,470




pg/L was reported for Cricotopus decorus (Ali and Mulla 1980) .




     Ahmed (1977) determined 24 hr. LCSOs in 6 species of aquatic coleopteran




and observed a range of 4.6 (jg/L to 52.0 Mg/L? he also cited for the same




test duration an LC50 of 15 ,jg/L for Belostoma sp.  Levy and Miller (1978)




observed the delayed effects of a 24-hr, exposure to 1.0 and 4.0 ^jg/L on




a planarian, Dugesia dorotocephala over 108 hrs.  They reported no




significant effects at either concentration.  Siefert et al. (1984) cited




LCSOs for various durations with Chaoborus.  Daphnia. a pigmy backswimmer,




an amphipod and a mayfly.




     Several studies have provided interesting information of the effects




of chlorpyrifos, although are not suited for inclusion in data used to




derive numerical water quality criteria.  Winner et al.  (1978) used a




single chlorpyrifos concentration (E.G.) in an experiment on the effects




in a merraithid nematode parasite of mosquito larvae.  They examined




toxicity to infectious, parasitic, post-parasitic, and embryo stages of




the nematode.  Rawn et al-  (1978) investigated the effect of various




sediments on the toxicity of chlorpyrifos to larvae of a mosquito in




artificial ponds.  They found lower toxicity and lower water residues in




sod-lined ponds compared to sand-lined ponds at equal application rates.




Macek et al. (1972) conducted a field study which included analysis of




fish brain AChE activity, fish stomach contents, residues in fish and




water, numbers of larval insects, and numbers of emerging insects.

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Siefert et al. (1984) conducted an extensive survey of changes within a




natural pond after chlorpyrifos was applied using standard methods employed




by pest control authorities.  Their study included analysis of water




quality, fish and invertebrate populations, and associated laboratory




studies.




     Schaeffer and Dupros (1970) examined the effect of polluted waters




on the stability of chlorpyrifos in the field.  As part of a laboratory




study, El-Refai et al. (1976) tested the effectiveness of a simulated




water treatment facility in lowering toxicity of Nile River water spiked




with chlorpyrifos.  They found a 332 decrease in toxicity with alum




treatment, and no significant change with sand filtration.




     Jamnback and Frempang-Boadu (1966), Mohsen and Mulla (1981). and




Muirhead-Thomson (1978, 1979) observed delayed effects after short exposures.






Unused Data




     Some data on the effects of chlorpyrifos on aquatic organisms were




not used because the studies were conducted with species that are not




resident in North America (e.g.. Moorthy et al.  1982).  Results of tests




reported by Ali (1981). Ferguson et al. (1966);  Naqvi (1973): and Nelson and




Evans (1973) were not used because the test organisms probably had been




previously exposed to pesticides or other pollutants.  Ramke (1969) only




presented data that have been published elsewhere.




     Data were not used if the test was on a commercial formulation (e.g.,




At allah and Ishak 1971; Birmingham and Colman 1977: Chang and Lange 1967;




Hurlbert et al. 1970: Ledieu 1978; Mulla et al.  1973: Roberts and Miller




1971; Scirocchi and D'Erme 1980: Siefert et al.  1984; Smith et al. 1966)




or if the source of the chlorpyrifos was not adequately described (e g.,




Ali and Mulla 1976, 1977: Boike and Rathburn 1969; Gillies et al. 1974;




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Johnson 1977b, 1978b; Kenaga et al. 1965; Micks and Rougeau 1977; Muirhead-




Thomson and Merryweather 1969; Ruber and Kocor 1976; Thayer and Ruber




1976; Wilder and Schaefer 1969; Zboray and Gutierrz 1979).  Data were not




used if Che organisms were exposed to chlorpyrifos by injection or gavage




or in food (e.g., Wilton et al. 1973) or if chlorpyrifos was a component




of a mixture (Meyer 1981), or were fed during exposure in short term




tests (Karnak and Collins 1974).  The concentration of solvent was too




high in the tests of Davey et al. (1976) and Al-Khatib (1985).  Barton




(1970) conducted a static chronic test with mosquito larvae.  Because




polyethylene sorbs chlorpyrifos (Brown et al. 1976; Hughes 1977; Hughes




et al. 1980), toxicity tests conducted in polyethylene were not used




(e.g., Brown and Chow 1975; Darwazeh and Mulla 1974; Dixon and Brust




1971; Hughes 1977; Miller et al. 1973; Roberts et al. 1973a, b).  Results




of some laboratory tests were not used because the tests were conducted




in distilled or deionized water without addition of appropriate salts




(e.g., Jones et al. 1976: Nelson and Evans 1973; Rongsreyam et al. 1968;




Steelman et al. 1969).  High control mortalities occurred in tests reported




by Khudairi and Ruber (1974),  Test procedures were inadequately described




by Ruber and Baskar (1969).  Roberts and Miller (1970) tested only one




concentration of chlorpyrifos.  BCFs obtained from microcosm or model




ecosystem studies were not used if the concentration of chlorpyrifos in




water decreased with time or if the exposure was too short (e.g., Metcalf




1974).  Results of field tests were not used if the concentrations of




chlorpyrifos were not measured (e.g., Ali and Mulla 1976, 1977, 1978a, b




Axtell et al. 1979; Best. 1969: Carter and Graves 1972; Chang and Lange




1967; Chatterji et al. 1979; Cooney and Pickard 1974; Evans et al. 1975;




Frank and Sjogren 1978; Hazeleur 1971; Hoy et al. 1972: Jamnback 1969;
                                    11

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Lembright  1968; Linn  1968; McNeill et al.  1968; Moore  and  Breeland 1967;

Mulla and  Khasawinah  1969: Mulla et al.  1971; Nelson et al.  1976a, b;

Polls et al.  1975: Roberts et al.  1984;  Steelman et al. 1969; Stewart

1977: Tawfik  and Gooding  1970: Taylor and  Schoof 1971; Thompson et al.

1970: Wallace et al.  1973; Washino et al.  1968, 1972a, b;  Wilkinson et

al.  1971;  Winterlin et al. 1968: Yap and Ho  1977) or if the  concentration

in water was  not uniform  enough (e.g., Macek et al. 1972).
     The acute values for eighteen species in fifteen genera range from

greater than 806 yg/L for two  fishes and a snail to 0.11 iJg/L for an

amphipod.  The bluegill is the most acutely sensitive fish  species with

an acute value of 10 (Jg/L, but seven invertebrate genera are more sensitive

Larger organisms seem to be less sensitive.

     Chronic toxicity data are available for one species, the fathead

minnow.  Unacceptable effects occurred to second generation larvae at

0.12 Mg/L, which was the lowest concentration tested.  The  resulting

acute-chronic ratio was greater than 1.400.

     Little information is available on the toxicity of chlorpyrifos to

aquatic plants, although a consistent observation of increased algal

blooms is frequently reported  associated with chlorpyrifos  application.

The only available bioconcentration test on chlorpyrifos with freshwater

species was with the fathead minnow and resulted in a BCF of 1,673.


Ktatipnal Criteria

     The procedures described  in the "Guidelines for Deriving Numerical

National Water Quality Criteria for the Protection of Aquatic Organisms

and Their Uses" indicate that, except possibly where a locally important

species is very sensitive, freshwater aquatic organisms and their uses
                                    12

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should not be affected unacceptably if the four-day average concentration




of chlorpyrifos does not exceed AAA jJg/L more than once every three years




on the average or if the one-hour average concentration does not exceed




0.083 Mg/L more than once every three years on the average.




     The procedures described in the "Guidelines for Deriving Numerical




National Hater Quality Criteria for the Protection of Aquatic Organisms




and Their Uses" indicate that, except possibly where a locally important




species is very sensitive, saltwater aquatic organisms and their uses




should not be affected unacceptably if the four-day average concentration




of chlorpyrifos does not exceed pig/L more than once every three years on




the average and if the one-hour average concentration does not exceed yyy




»jg/L more than once every three years on the average.




     The allowed excursion frequency of three years is based on the




Agency's best scientific judgment of the average amount of time it will




take an aquatic ecosystem to recover from a pollution event in which




exposure to chlorpyrifos exceeds the criterion.  The resilience of




ecosystems and their ability to recover differ greatly, however, and site-




specific criteria may be established if adequate justification is provided.




     The use of criteria in designing waste treatment facilities requires




selection of an appropriate wasteload allocation model.  Dynamic models




are preferred for the application of these criteria.  Limited data or other




factors nay make their use impractical, in which case one must rely on a




steady-state model.  The Agency recommends interim use of 1Q10 for




Criterion Maximum Concentration (CMC) design flow and 7Q10 for the




Criterion Continuous Concentration (CCC) design flow in steady-state




models.  These matters are discussed in more detail in the Technical




Support Document for Water Quality-Based Toxics Control (U.S. EPA 1985)




and the Design Flow Manual (U.S. EPA 1986).




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                      Tab)* 1.  Acute Toxlclty of Ct>IorpyrIfo» to Aquatic Animals
CC90 Species Mean
or EC50 Acute Value
Species Method* Cham leal (pg/L) (»g/L> Reference
Snail (adult),
Aplexa hypnorum
Amphlpod,
Gammarus fasctatus
Amphlpod (2 no. old),
Gammarus lacustrls
Amphlpod,
Gammarus pseudol Imnaeus
Crayfish ( 1 .8 g) ,
Orconectes Immunls
Stonefly (naiad),
Pteronarcel la bad la
Stonefly (naiad),
Pteronarcys callfornlca
Stonefly (naiad),
Claassenta sabulosa
Trlchopteran,
Leptocerldae sp.
Pyqmy backs wlmmer,
Neoplea strlola
Pygmy backswlmmer ,
Neoplea strlola
Crawling water beetle
(adult).
Pel tody tes sp.
FRESHWATER
f, M Technical
S, U Technical
S, U Technical
F, M Clarke**
F, M Technical
S, U Technical
S, U Technical
S, U Technical
S, M Clarke**
S, M Clarke**
S, M Clarke**
S, U
SPECIES
>806 >806 Phlpps and Hoi combe
1985a,b
0.32 0.52 Sanders 1972
O.I.I 0.11 Sanders 1969; Johnson
and Flnley 1980
0.18 0.18 Slefert et al . 1984
6 6 Phlpps and Ho) combe
1985a,b
0.38 0.38 Sanders and Cope 1968
10 10 Sanders and Cope 1968;
Johnson and Flnley 1980
0.57 0.57 Sanders and Cope 1968;
Johnson and Flnley 1980
0.77 0.77 Slefert et al . 1984
1.22 - Slefert et al. 1984
1.56 1.38 Slefert et al . 1984
0.8 0.8 Federle and Collins
1976
Cutthroat trout (1.4 g),
Satmo clorklI
S, U
          Technical
18
                                         18
Johnson and Flnley 1980

-------
TabU 1.  (continued)
Specie*                      Method*    Chemical

Rainbow trout (0.6-1.5 g),    S, 0      Technical
Salmo galrdnerl

Rainbow trout (Juvenile),     F, M      Technical
Salmo qalrdnerl

Rainbow trout (3.0 g) ,        F, M      Technical
Salmo galrdnerl

Lake trout (2.3 g),           S, U      Technical
Salvellnus namaycush

Goldfish (10.7 9),            F, M      Technical
Carass Ius auratus

Fathead minnow,               S, M      Technical
Plmephales promelas^

Fathead minnow (juvenile),    F, M      Technical
Plmephales j>rpme|as^

Fathead minnow (0.5 g),       F, M      Technical
Plmephales prometas

Channel catfish (0.8 g),      S, U      Technical
Ictalurus punctatus

Channel catfish (7.9 g),      F, M      Technical
I eta I urus punctatus^

Blueglll (0.6 g) ,             S, U      Technical
Lepomls macrochlrus

Blueqlll (0.8 g),             F, M      Technical
Lepomls macrochlrus
                                                       LC50      Spiles Mean
                                                     or EC50     Acute Value
   7.1


   8.0


   9


  98


>806


 170


 203


 542


 280


>806


   2.4


  10
   8.485


  98


>806
 331.7
 806
  10
             Reference

             Macek et at.  1969;
             Johnson and Fin ley 1980

             Hoi combe et al. 1982
Phlpps and Holconbe
1985a,b

Johnson and Fin ley 1980
Phlpps and MoI combe
1985a,b

Jarvlnen and Tanner
1982

HoIcombe et al. 1982
Phlpps and HoI combe
1985a.b

Johnson and Flnley 1980
Phlpps and HoI combe
1985a,b

Johnson and Flnley 1980
Phtpps and Hoi combe
1985a,b
*  S " static; R « renewal; F » flow-through; U » unmeasured; M » measured.

** Clarke » encapsulated technical chlorpyrIfos; doses prepared separate from test chamber.

-------
 Table 2.  Chronic Toxic Ity of Chlorpyrlfos  to Aquatic AnlMl

Species Test*

Fathead minnow, ELS
Plmephales promelas
Fathead minnow, ELS
Plmephales promelas
Fathead minnow, LC
Plmephales promalas
Fathead minnow (second ELS
generation),
Plmephales promelas
Limits Chronic Valu*
Chemical (ugA) (nq/L)
FRESHWATER SPECIES
Technical 1.6-3.2 2.263

Encapsulated 2.2-4.8 3.250

Encapsulated 0.27-0.63 0.4124

Encapsulated <0.12"» <0.12




Reference

Jarvlnen
1982
Jarvlnen
1982
Jarvlnen

Jarv Inen



and Tanner

and Tanner

et al. 1983

et al. 1983


* LC » life-cycle or partial life-cycle; ELS = early life-stage.
** Unacceptable effects occurred at


Specie*
Fathead minnow.
al 1 tested concentrations.
Acute-Chronic Ratio
Acute Valu* Chronic Value
(»gA) (»q/L)



Ratio




170 l,417
Plmephales promelas

-------
Table 3.  Ranked Genus Mean Acute Value* with Species Mean Acute-Chronic Ratios
tank*
15
14
13
12
It
10
9
8
7
6
5
4
Genus Mean
Acute Value
806
>806
806
331.7
98
12.36
10
to
6
1.38
0.8
0.77
Species
FRESHWATER SPECIES
Snail,
Aplexa hypnorum
Goldfish,
Car ass 1 us auratus
Channel catfish,
Ictalurus punctatus
Fathead minnow,
Plmephales promelas
Lake trout,
Salvellnus namaycush
Cutthroat trout,
Salmo clarkl
Rainbow trout,
Salmo qalrdnerl
Stonef ly,
Pteronarcys callfornlca
Blueqlll,
Lepomls macrochlrus
Crayfish,
Orconectes Immunls
Pygmy backs w 1 mmer ,
Neoplea strlola
Crawling water beetle,
Pel tody tes sp.
Trlchoptera
Species Mean
Acute Value
(»g/L)M
>806
>806
806
331.7
98
18
8.485
10
10
6
1.38
0.8
0.77
Species Mean
Acute-Chronic
Retlo""
> 1,4 17
                      Leptocer Idae sp.

-------
Tabla 3.  (continued)
Rank"
3
2
1
Genus Maan
Acuta Value
(ng/L) Species
0.57 Stonef ly,
Claasenla sabulosa
0.38 Stonef ly,
P teronarce 1 1 a bad 1 a
0.1850 Amph 1 pod.
Gammarus fasclatus
Amph 1 pod ,
Gammarus lacustrls
Amph I pod ,
Gammarus pseudol Imnaeus

Specie* Maan
Acuta Value
0.57
0.38
0.32
O.It
0.1B
Specie* Maan
Acute-Chronic
Ratio***
-
*   Rankad from most resistant to most sensitive based on Genus Mean Acute Value.



*»  From Table I.



•»» From Table 2.





Fresh water
     Final Acute Value = 0.1669 pg/L



     Criterion Maximum Concentration = (O.t669 ug/L) / 2 * 0.08345 i»9/t

-------
                                    Tabla 4.  Bloconcantratlofl of CMorpyrlfo* by Aquatic Organ I


                                                Concentration        Duration
Spaclaa                        Cnaalcal*       In Watar (pg/D**      (days)       Tl««ua     BCF  or BAF***     Rafaranc*

                                                           FRESHWATER SPECIES
Fathead minnow,               Encapsulated        0.12-2.68             60        Whole         1,673           Jarvlnen  at al. 1983
Ptmaphatas promelas                                                               body

-------
                           Table 5.  Other Data on Effects of Chlorpyrlfos on Aquatic Organises
Species
Chenlcel
Duration
Effect
Result
(jig/L)*      Reference
FRESHWATER SPECIES
Planarla,
Duqesla dorotocepha 1 a
Cladoceran,
Daphnle sp.
Amp hi pod,
Hyalet la azteca
Mayfly.
Ephemeral! a sp.
Pygmy backs wlmmer,
Neoplea strict a
Giant water bug (adult),
Belostoma sp.
Predaceous dlvlnq beetle
(adult),
Hygrotus sp.
Predaceous diving beetle
(adult),
Laccophl lus declplens
Predaceous diving beetle
(adult),
Thermonectus basil larls
Water scavenger beetle
(adult),
Berosus sty lifer us
Mater scavenger beetle
108 hr
Clarke* 4 hr
Clarke* 24 hr
Clarke* 72 hr
Clarke* 144 hr
Technical 24 hr
Technical 24 hr
Technical 24 hr
Technical 24 hr
Technical 24 hr
Technical 24 hr
Delayed effects No effect Levy and M
after 24 hr detected at
exposure 1.0 and 4.0
LC50
LC50
LC50
LC50
LC50
LC50
LC50
LC50
LC50
LC50
0.88 Slefert et
1.28 SUtert et
0.33 Slefert et
0.97 Slefert et
13 Ahmed 1977
40 Ahmed 1977
4.6 Ahmed 1977
6 Ahmed 1977
9 Ahmed 1977
20 Ahmed 1977
(larva),
Hydrophllus trlangularls

-------
Table 9.   (continued)
                                                                                 Result
Species
Mater scavenger beetle
(adult).
Hydrophllus trlangularls
Mater scavenger beetle
( larva) ,
Troplsternus lateral Is
Mater scavenger beetle
(adult),
Troplsternus lateral Is
Mosquito (3rd and 4th
Instar) ,
Aedes aegyptl
Mosquito (2nd Instar),
Aedes oeqyptl
Mosquito (4th Instar),
Aedes aegyptl
Mosquito (4th Instar),
Aedes cantans
Mosquito (4th Instar),
Aedes common Is
Mosquito (4th Instar),
Aedes excruclans
Mosquito (4th Instar),
Aedes punctor
Mosquito (4th Instar),
Aedes stlctlcus
Mosquito (4th Instar),
Aedes vexans
Mosquito ( larva) ,
Chemical
Technical
Technical
Technical
Technical
Technical
Technical
Techn leal
Technical
Technical
Techn leal
Technical
Technical
Technical
Duration
24 hr
24 hr
24 hr
18 hr
24 hr
24 hr
24 hr
24 hr
24 hr
24 hr
24 hr
24 hr
24 hr
Effect
LC50
LC50
LC50
LT50
LC50
LC50
LC50
LC50
LC50
LC50
LC50
LC50
LC50
                                                                                 30
                                                                                 52
                                                                                 10
                                                                                  0.0011
                                                                                  1.1

                                                                                  3.5

                                                                                  3.3

                                                                                  2.7

                                                                                  0.5

                                                                                  J.O

                                                                                  3
Reference
Ahmed  1977
                                                                                              Ahmad 1977
                                                                                              Ahmed 1977
Verma and Rahman 1984
Sal eh et al. 1981
                                                                                  0.0014      Sal eh et al.  1981
Rettlch 1977

Rettlch 1977

Rettlch 1977

Rettlch 1977

Rettlch 1977

Rettlch 1977

Ahmed 1977
Anopheles freebornl

-------
Table 5.  (continued)
Species
MosqultoHsh,
G ambus la at finis
Guppy,
Poecllla retlculata
Green sunflsh,
Lepomls cyanellus

Chealcal Duration
24 hr
Technical 24 hr
Technical 36 hr
Effect
LC50
LC50
LC50
Result
4,000
220
37.5
22.5
Reference
Hansen et al .
Ronqsrlyam et
Ferguson et al
1972
al. 1968
. 1966
*  Clarke » encapsulated technical chlorpyrIfos; doses prepared separate from test chamber.
** Aged II weeks.

-------
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