APPENDIX E. Summary of Aquatic Ecological Effects Data for 

Endosulfan 

This appendix is a summary of the data being evaluated for ecological effects on aquatic 

organisms. Each section consists of several sets of data. Tables presenting the data 

submitted with the application for registration are presented first. Within a taxonomic 

group, the lowest value from this table is used to set a toxicity reference value that is used 

in evaluating the data from the open literature—from EPA’s ECOTOX database. Only 

the studies associated with the ECOTOX data that have values less than these toxicity 

reference values are examined further. If any of these latter values are acceptable, then 

that value becomes the final value used in the risk assessment for that particular 

taxonomic group. 

Because the stability of endosulfan TGAI in aquatic tests is a concern due to its volatility, 

preference was given to those studies that quantified endosulfan exposure via analytical 

measurements and where appropriate, used a flow-through exposure regime. In some 

cases, however, these data were lacking (e.g., aquatic nonvascular plants), and toxicity 

values based on nominal concentrations were used to fulfill a data gap. In general, 

studies from the open literature do not provide sufficient documentation for evaluating all 

or most of the OPPTS Guideline evaluation criteria. Consistent with the Overview 

Document (USEPA 2004), if sufficient documentation was provided to judge that the 

open literature studies were scientifically valid and acceptable endpoints were determined 

that were below the toxicity reference values, they were typically classified as 

supplemental--but acceptable for quantitative use. If sufficient documentation was not 

provided to comprehensively judge the scientific validity of the study but no information 

existed that suggested the study would be invalid, these studies were typically classified 

as supplemental--but acceptable for qualitative use. This classification was often applied 

to studies with nominal exposure concentrations. 

I. Acute Toxicity to Freshwater Fish 

 Submitted Data for Freshwater Fish Acute Values 

Two freshwater fish toxicity studies using the TGAI are required to establish the toxicity 

of endosulfan to fish. The preferred test species are rainbow trout (a coldwater fish) and 

bluegill sunfish (a warmwater fish). Rainbow trout were the most sensitive (LC50 = 0.83 

μg/L) species tested (Table E-1). Since the LC50 value was less than 0.1 mg/L, 

endosulfan is categorized as very highly toxic to freshwater fish on an acute exposure 

basis. The freshwater fish acute toxicity testing requirement (Guideline 72-1) is fulfilled 

(MRID 38806, 40094602, 40098001, 136999, 05008271). 

Endosulfan Sulfate Toxicity 

Acute toxicity of endosulfan sulfate on freshwater fish was tested using bluegill sunfish. 

The 96-hour LC50 of endosulfan sulfate on bluegill was 3.8 μg/L and is considered very 

highly toxic (MRID 46382604). Acute toxicity testing of endosulfan sulfate (99.9% 

radiopurity) was also tested with common carp (Gries and van der Kolk, 2000a; MRID 

E-1
45421402), which also indicated that the degradate is very highly toxic (96-hr LC50 = 2.2 

μg/L) to freshwater fish. The study was classified as supplemental since it failed to 

comply with EPA’s recommended species and testing conditions. These results are 

consistent with studies of parent endosulfan where 96-hr LC50 values ranged from 0.37 

to 3.3 μg/L. 

Formulated End Use Product 

The acute toxicity of endosulfan to freshwater fish was tested using technical end 

product. There was considerable variability for LC50 values within formulations tested; 

toxicity estimates ranged from 0.47 μg/L to 5.6 μg/L for the 50 WP and 33.7% 

formulations, respectively (Table E-2). Similar to the results on technical grade active 

ingredient, rainbow trout were the most sensitive species tested using technical end 

product. Of the formulated products tested, the 4% formulation was the least toxic with 

an LC50 estimate of 28 μg/L. Based on the test results, the formulation of endosulfan is 

classified as being very highly toxic to freshwater fish species. The freshwater fish acute 

toxicity testing requirement using technical end product (Guideline 72-1) is fulfilled 

(MRID 00128655, BA007902, 250401A). 

Additional Open Literature Information (ECOTOX) for Freshwater Fish Acute Values 

All of the open literature acute values from EPA’s ECOTOX database for freshwater fish 

are presented in Figure E-1. The vertical line represents the toxicity reference value from 

the registrant’s data (0.83 ug/L). These data are primarily for an exposure duration of 4 

days; however, other durations were included (e.g., 1 or 2 day exposures) if there was no 

4 day LC50 for a particular test. Tables E-3 and E-4 contains the acute LC50 values that 

are less than this toxicity reference value. When LC50 values for multiple exposure 

durations from the same test were available, only the value for 4 day exposure was 

included. There were 150 LC50 values from 35 open literature studies representing 31 

freshwater fish species. Forty-five of these values were below the freshwater fish toxicity 

reference value (0.83 μg/L) that was based on the information provided by the registrant. 

These data are presented in nine different studies and represent 13 species. 

E-2
Endosulfan: Freshwater Fish LC50s

n = 150

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.1 1 10 100 1000 10000

Concentration (ug/L)

Probability Rank

Figure E-1. Plot of the freshwater fish endosulfan acute data. 

Forty-eight 96 hr LC50 values are available from an interlaboratory comparison of acute 

tests for large subadults of the fathead minnow Pimephales promelas and fingerlings of 

the rainbow trout Oncorhynchus mykiss (Lemke1981—ECOTOX reference # 9479). All 

of the laboratories used the same technical grade endosulfan. For each fish species there 

are 24 LC50 values, 12 from static tests and 12 from flow-through tests. The static test 

values for fathead minnows ranged from 0.97 to 3.45 μg/L (all values are above the 

toxicity reference value). The 12 flow-through tests for this species had LC50s ranging 

from 0.29 to 1.91 μg/L (seven of these values were below the toxicity reference value). 

The static tests for rainbow trout ranged from 0.49 to 2.43 μg/L (six of these 12 values 

were below the toxicity reference value) and the flow-through tests had values ranging 

from 0.17 to 0.75 μg/L (all 12 values below the toxicity reference value). 

And additional set of fourteen 96 hr LC50s are presented in Sunderam et al. (1992—

ECOTOX reference # 5850). These data are for eight species of fish from Australia. Six 

of the eight species had at least one LC50 values less than the toxicity reference value. 

These are the golden perch Macquaria ambigua, the common carp Cyprinus carpio, the 

eastern rainbow fish Melanotaenia duboulayi, the bony bream Nematolosa erebi, the 

harlequinfish Rasbora sp. and the rainbow trout Oncorhynchus mykiss. The endosulfan 

used was technical grade, and the common carp was the most sensitive species in this 

study and was the most sensitive freshwater fish overall with an LC50 of 0.1 μg/L. 

Seven tests in 1988 and 1989 used the striped bass Morone saxatilis and yielded similar 

LC50 values, ranging from >0.22 to 0.43 μg/L (Fujimura et al. 1991—ECOTOX 

reference # 15472). All of the tests used larval fish, ranging in age from 6 to 45 days post 

hatch, and were conducted as flow-through tests. 

Adult Asian swamp eels, Monopterus albus, were tested using a commercial endosulfan 

end product (33% purity—mixture of α and β endosulfans). The 96 hr LC50 obtained in 

this study was 0.42 μg endosulfan/L (Hii et al. 2007—ECOTOX reference # 100663). 

E-3
Another study using males and females of Jenynsia multidentata—also with a 

commercial preparation (35% purity)—demonstrated that males may be more sensitive 

than females; the 96 hr LC50s were 0.719 and 1.317 μg endosulfan/L, respectively 

(Ballesteros et al. 2007—ECOTOX reference # 103207). 

Three different studies compared various forms of endosulfan; α and β endosulfans, 

technical grade mixture of the two, as well as commercial sources of powders and 

emulsified concentrates (Table E-5). In each case the α-endosulfan was the most toxic 

form, and the only form with an LC50 less than the toxicity reference value. Juveniles of 

Labeo rohita had an LC50 of 0.33 μg/L for the α form; compared with 7.1 for the βendosulfan and 1.0 to 1.25 for the technical grade and commercial preparations (Rao et 

al. 1980—ECOTOX reference # 468). The snake-head catfish, Channa punctata had an 

LC50 of 0.16 μg/L for α-endosulfan, and the other forms of endosulfan all had LC50s 

from 2.5 to 16 μg/L (Devi, et al. 1981—ECOTOX reference # 15157). Finally, the 96 hr 

LC50 for α-endosulfan for the rainbow trout Oncorhynchus mykiss (Wan et al. 2005—

ECOTOX reference # 87973) is 0.5 μg/L, in addition, a 60/40 mixture of α- and βendosulfans resulted in an LC50 of 0.7 μg/L. The other forms of endosulfan had LC50s 

greater than the toxicity reference value. This included the only freshwater fish acute test 

from the ECOTOX data set that used endosulfan sulfate (LC50 of 1.4 μg/L). In almost all 

cases the commercial end product was less toxic (based on active ingredient) than the 

technical grade. 

Table E-1. Summary of freshwater fish acute toxicity data submitted by registrant 

for endosulfan

Species/Flowthrough or Static % ai 96-hour 

LC50 (μg/L) 

Toxicity 

Category 

MRID No. 

Author/Year 

Study 

Classification 

Bluegill sunfish 

(Lepomis 

macrochirus)

96 2.08 very highly 

toxic 

BA007903/ 

EPA 1976 supplemental 

Bluegill sunfish 

(Lepomis 

macrochirus)

100 1.7 very highly 

toxic 

38806/ 

Buccafusco 1976 acceptable 

Bluegill sunfish 

(Lepomis 

macrochirus)

96.6 3.3 very highly 

toxic 

05014941/Pickering 

&Henderson 1966 supplemental 

Bluegill sunfish 

(Lepomis 

macrochirus) static 

96 1.2 very highly 

toxic 

40094602/ 

Johnson&Finley 1980 supplemental 

Rainbow trout 

(Oncorhynchus 

mykiss) static 

techa 1.5b very highly 

toxic 

05003107/ 

Macek et al. 1969 supplemental 

Rainbow trout 

(Oncorhynchus 96 1.1b very highly 

toxic 

40098001 

Mayer & Ellerisieck supplemental 

 

a

 Thiodan : tested as μg active ingredient per liter. 

b

 Tested at several temperatures, this is the LC50 for the highest temperature tested. 

E-4
Species/Flowthrough or Static % ai 

96-hour 

LC50 (μg/L) 

Toxicity 

Category 

MRID No. 

Author/Year 

Study 

Classification 

mykiss) static 1986 

Rainbow trout 

(Oncorhynchus 

mykiss) static 

95.9 0.83 very highly 

toxic 

136999/ 

Fischer 1983 acceptable 

Rainbow trout 

(Oncorhynchus 

mykiss) static 

96 0.37 very highly 

toxic 

BA007902/ 

EPA 1976 supplemental 

Channel catfish 

(Ictalurus nebulosus) 

static 

96 1.5 very highly 

toxic 

40094602/ 

Johnson&Finley 1980 supplemental 

Fathead minnow 

(Pimephales 

promelas) static 

96 1.5 Very highly 

toxic 

40094602/ 

Johnson&Finley 1980 supplemental 

Fathead minnow 

(Pimephales 

promelas) Flowthrough 

99 0.86c very highly 

toxic 

05008271/ 

Macek et al. 1976 acceptable 

Table E-2. Summary of freshwater fish acute toxicity data submitted by registrant 

for commercial endosulfan end products 

Species/ 

Flow-through or 

Static 

% ai 

96-hour 

LC50 (μg/L) Toxicity 

Category 

MRID No. 

Author/Year 

Study 

Classification 

Bluegill sunfish 

(Lepomis macrochirus) 33.7 5.6 very highly 

toxic 

00128656/ 

Kinter& Forbis 

1983 

supplemental 

Bluegill sunfish 

(Lepomis macrochirus) 50WP 3.9 very highly 

toxic 

00128655/ 

Kinter& Forbis 

1983 

acceptable 

Rainbow trout 

(Oncorhynchus mykiss) 

static 

50WP 0.47 very highly 

toxic 

BA007902/EPA 

1976 acceptable 

Rainbow trout 

(Oncorhynchus mykiss) 

static 

50WP 2.3 very highly 

toxic 250401A acceptable 

Rainbow trout 

(Oncorhynchus mykiss) 

static 

33.7 2.7 very highly 

toxic 

00128655/Kinter

& Forbis 1983 supplemental 

Rainbow trout 

(Oncorhynchus mykiss) 

static 

4 28 very highly 

toxic 

0033020/ 

Ludeman 1972 supplemental 

Common carp 

(Cyprinus carpio) static 

35 0.92a very highly 

toxic 

05004792/Basak

& Konar 1976 supplemental 

 

c

 7-day LC50; however, similar to expected 96 hr LC50 (see text). 

E-5
Species/ 

Flow-through or 

Static 

% ai 

96-hour 

LC50 (μg/L) Toxicity 

Category 

MRID No. 

Author/Year 

Study 

Classification 

 Indian catfish 

(Heteropneustes 

fossilis) static 

35 1.57a very highly 

toxic 

05004792/Basak

& Konar 1976 supplemental 

Mozambique tilapia 

(Tilapia mossambica)

static 

35 1.4a very highly 

toxic 

05004792/Basak

& Konar 1976 supplemental 

a

7-day LC50 

Table E-3. Summary of freshwater fish acute data from EPA’s ECOTOX database 

that was less than the toxicity reference value of 0.93 μg/L. The shaded row is the 

lowest value. 

Chemical 

Name Genus Species Common Name Dur (da) 

LC50 

(ug/L) 

% 

a.i. Ref # Comment 

α Endosulfan Channa punctata Snake-head catfish 4 0.16 100 15157 supplemental 

Endosulfan Cyprinus carpio common carp 4 0.1 96.2 5850 Supplemental 

α Endosulfan Labeo rohita Rohu 4 0.33 100 468 Supplemental 

Endosulfan Macquaria ambigua Yellowbelly, Golden 

Perch 4 0.3 96.2 5850 Supplemental 

Endosulfan Macquaria ambigua Yellowbelly, Golden 

Perch 4 0.5 96.2 5850 Supplemental 

Endosulfan Melanotaenia duboulayi Eastern rainbow 

fish 4 0.5 96.2 5850 Supplemental 

Endosulfan Morone saxatilis Striped bass 4 > 0.22 100 15472 Supplemental 

Endosulfan Morone saxatilis Striped bass 4 0.23 100 15472 Supplemental 

Endosulfan Morone saxatilis Striped bass 4 0.23 100 15472 Supplemental 

Endosulfan Morone saxatilis Striped bass 4 0.29 100 15472 Supplemental 

Endosulfan Morone saxatilis Striped bass 4 <0.33 100 15472 Supplemental 

Endosulfan Morone saxatilis Striped bass 4 0.35 100 15472 Supplemental 

Endosulfan Morone saxatilis Striped bass 4 0.43 100 15472 Supplemental 

Endosulfan Nematolosa erebi Bony bream 4 0.2 96.2 5850 Supplemental 

Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.17 100 9479a supplemental: 

measured

Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.24 100 9479 supplemental: 

measured

Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.26 100 9479 supplemental: 

measured

Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.26 100 9479 supplemental: 

measured

Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.27 100 9479 supplemental: 

measured

Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.29 100 9479 supplemental: 

measured

Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.3 100 9479 supplemental: 

measured

E-6
Chemical 

Name Genus Species Common Name Dur (da) 

LC50 

(ug/L) 

% 

a.i. Ref # Comment 

Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.32 100 9479 supplemental: 

measured

Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.41 100 9479 supplemental: 

measured

Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.42 100 9479 supplemental: 

measured

Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.49 100 9479 supplemental: 

measured

α Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.4975 99.5 87973 

supplemental 

Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.63 100 9479 supplemental: 

measured

Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.69 100 9479 supplemental: 

measured

Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.69 100 9479 supplemental: 

measured

Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.693 99 87973 

supplemental 

Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.7 96.2 5850 

supplemental 

Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.75 100 9479 

supplemental 

Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.79 100 9479 supplemental: 

measured

Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.8 100 9479 supplemental: 

measured

Endosulfan Oncorhynchus mykiss 

Rainbow 

trout,donaldson 

trout 

4 0.89 100 9479 supplemental: 

measured

Endosulfan Pimephales promelas Fathead minnow 4 0.29 100 9479 supplemental: 

measured

Endosulfan Pimephales promelas Fathead minnow 4 0.45 100 9479 supplemental: 

measured

Endosulfan Pimephales promelas Fathead minnow 4 0.73 100 9479 supplemental: 

measured

Endosulfan Pimephales promelas Fathead minnow 4 0.75 100 9479 supplemental: 

measured

Endosulfan Pimephales promelas Fathead minnow 4 0.76 100 9479 supplemental: 

measured

Endosulfan Pimephales promelas Fathead minnow 4 0.8 100 9479 supplemental: 

measured

Endosulfan Pimephales promelas Fathead minnow 4 0.81 100 9479 supplemental: 

measured

Endosulfan Rasbora sp. Harlequinfish, red 

rasbora 4 0.2 96.2 5850 supplemental 

Endosulfan Tilapia nilotica Nile tilapia 2 0.69 100 20421 supplemental 

a part of an EPA Interlaboratory Comparison Study—measured values and standard methods 

E-7
Table E-4. Summary of freshwater fish acute data for commercial endosulfan end 

products from EPA’s ECOTOX database. 

Chemical 

Name Genus Species Common Name Dur (da) 

LC50 

(ug/L) 

% 

a.i. Ref # Comment 

Endosulfan Jenynsia multidentata Onesided Livebearer 4 0.719 35 103207 supplemental 

Endosulfan Monopterus albus Swamp or White 

Ricefield Eel 4 0.42 33 100663 supplemental 

Table E-5. Summary of freshwater fish acute data from ECOTOX in which multiple 

sources of endosulfan were tested using the same species. Note, most are not below 

the freshwater fish toxicity reference value. 

Chemical 

Name Genus Species Common Name 

Dur 

(da)

LC50 

(ug/L)

% 

a.i. Ref # Comment 

α-Endosulfan Labeo rohita Rohu 4 0.33 - 468 supplemental

β−Endosulfan Labeo rohita Rohu 4 7.1 - 468 supplemental

(α+β) -

Endosulfan Labeo rohita Rohu 4 1.1 96 468 supplemental

35% EC Labeo rohita Rohu 4 1 35 468 supplemental

4% Dust Labeo rohita Rohu 4 1.25 4 468 supplemental

α-Endosulfan Channa punctata Channel 

catfish 4 0.16 - 15157 supplemental

β−Endosulfan Channa punctata Channel 

catfish 4 6.6 - 15157 supplemental

(α+β) -

Endosulfan Channa punctata Channel 

catfish 4 4.8 96 15157 supplemental

35% EC Channa punctata Channel 

catfish 4 2.5 35 15157 supplemental

4% Dust Channa punctata Channel 

catfish 4 16 4 15157 supplemental

α-Endosulfan Oncorhynchus mykiss Rainbow 

trout 4 0.5 99.5 87973 supplemental

β−Endosulfan Oncorhynchus mykiss Rainbow 

trout 4 3.3 99.3 87973 supplemental

(α+β) -

Endosulfan Oncorhynchus mykiss Rainbow 

trout 4 0.7 99 87973 supplemental

40% EC Oncorhynchus mykiss Rainbow 

trout 4 4.6 40 87973 supplemental

50% WP Oncorhynchus mykiss Rainbow 

trout 

4 3.5 50 87973 supplemental

Endosulfan 

Sulfate 

Oncorhynchus mykiss Rainbow 

trout 

4 1.4 98 87973 supplemental

E-8
II. Chronic Toxicity to Freshwater Fish 

Submitted Data for Freshwater Fish Chronic Values 

An estimate of the chronic toxicity of technical grade endosulfan to freshwater fish was 

obtained in two test using life cycle testing with the fathead minnows Pimephales 

promelas (Table E-6). In the study by Macek et al. (1976) there was no effect on survival 

or growth relative to the controls in the F1 generation (40 weeks of exposure) or on egg 

production, hatchability, survival or growth in the F2 generation (60 days of exposure) at 

0.20 μg/L. At the highest concentration tested (0.40 μg/L) there also was no effect on the 

F1 generation after 30 or 60 days; however, on day 170 there was a diluter malfunction 

and all of the fish died in this treatment. After 40 weeks, during the F2 exposure, eggs 

from the controls were added to the 0.40 treatment and 1% of them hatched. Therefore, 

0.40 μg/L was the LOEC. In the second study (Dionne 2002), the estimated lowest 

observed effect concentration is 0.11 μg/L based on reduced reproduction (# eggs/female, 

# eggs/spawn, #spawns/female) and growth (reduced terminal length in F0 males). The 

NOEC from this study is 0.056 μg/L, and this value is the toxicity reference value against 

which the ECOTOX data are evaluated. The chronic toxicity testing requirement for 

freshwater fish (Guideline 72-5) is fulfilled (MRIDs 45868601, 05008271). 

Additional Open Literature Information (ECOTOX) for Freshwater Fish Chronic Values 

There was only one study (Gormley and Teather 2003—ECOTOX Reference # 69838) 

which contained a chronic value less than the NOAEC value 0.056 μg/L. The NOEC 

from that study for both growth and reproduction was 0.01 μg/L; however, the next 

highest concentration tested was 0.1 μg/L and the effects at this concentration were 

minimal (although statistically significant) to non-existent. The chronic value for the 

common carp was calculated using the acute to chronic ratio for fathead minnow and the 

LC50 for carp. This resulting chronic value, 0.023 μg/L (Table E-5), is used in the risk 

assessment for freshwater fish. 

Table E-6. Summary of Freshwater flow-through fish life-cycle toxicity test using 

endosulfan

Species/Study 

Duration 

% 

ai 

NOEC/ 

LOEC 

μg/L 

Endpoints 

Affected 

MRID / 

Author Year 

Study 

Classification 

Fathead minnow 

(Pimephales 

promelas) 

340 days 

99 NOEC = 0.2 

LOEC= 0.4 Egg hatch 

05008271/ 

Macek et 

al.1976 

acceptable 

Fathead minnow 

(Pimephales 

promelas)

99 

NOEC = 

0.056 

LOEC= 0.11 

Reduced 

reproduction and 

growth 

45868601/ 

Dionne 2002 

supplemental 

Common carp 

(Cyprinus carpio) 

NOEC = 

0.023a -- -- -- 

a

 NOEC for common carp estimated using acute to chronic ratio for fathead minnow (0.86/0.20). 

E-9
III. Acute Toxicity to Freshwater Invertebrates 

Submitted Data for Freshwater Invertebrate Acute Values 

A freshwater aquatic invertebrate toxicity test using the TGAI is required to establish the 

toxicity of endosulfan to aquatic invertebrates. The preferred test species is Daphnia 

magna. Based on the available data (Table E-7) the estimated EC50 for technical grade 

endosulfan was 166 μg/L using daphnia, 5.8 and 6 μg/L for to species of Gammurus and 

2.3 μg/L for the stonefly Pteronarcys californica. Since the latter EC50 was less than 100 

μg/L, endosulfan is categorized as being very highly toxic to aquatic invertebrates on an 

acute exposure basis. The freshwater invertebrate acute toxicity testing requirement 

(Guideline 72-2) is fulfilled (MRID 5008271, 40098001, 40094602). 

Table E-7. Summary of freshwater invertebrate acute toxicity data submitted by 

registrant for endosulfan 

Species/Duration % ai 

LC/EC50 

(μg/L) 

Toxicity 

Category 

MRID No. 

Author/Year 

Study 

Classification 

Waterflea 

(Daphnia magna) 48 h 99 166 very highly toxic 

5008271/ 

Macek et al. 1976 acceptable 

Scud 

(Gammurus faciatus)

96 h 

96 6 very highly 

toxic 

40098001/ 

Mayer & Ellersieck 

1986 

supplemental 

Scud 

(Gammurus lacustris) 

96 h 

96 5.8 very highly 

toxic 

40094602/ 

Johnson& Finley 

1980 

supplemental 

Stonefly 

(Pteronarcys 

californica) 96 h 

96 2.3 very highly 

toxic 

40094602/ 

Johnson& Finley 

1980 

supplemental 

Acute toxicity testing endosulfan sulfate using Daphnia magna (99.4% active ingredient) 

indicated that the degradate is highly toxic (EC50 = 300 ug/L) to water fleas (Gries and 

van der Kolk, 2000b; MRID 45421403). The study was classified as supplemental since 

it was conducted using a water hardness (160 - 180 mg/L as CaCO3) outside of the 

recommended range (40 - 49 mg/L as CaCO3). These results are similar to the toxicity of 

the parent compound to aquatic invertebrates. 

Additional Open Literature Information (ECOTOX) for Freshwater Invertebrate Acute 

Values 

All of the open literature values from EPA’s ECOTOX database for freshwater 

invertebrates are presented in Table D-1 of Appendix D. A subset of this data 

representing the acute LC/EC50 values was compared against the toxicity reference value 

for freshwater invertebrate acute toxicity (2.3 μg/L). These data are for exposure 

durations ranging from 0.5 to 4 days and are shown in Figure E-2. If values for multiple 

durations were available from a single test, then only the longest duration value was used 

to make the comparison with the toxicity reference value. There were 89 LC/EC50 values 

from 37 open literature studies representing 42 freshwater invertebrate species. Twentyone of these values were below the toxicity reference value based on the information 

E-10
provided by the registrant. These data are presented in nine different studies and represent 

13 species. These data are summarized in Table E-8. Note that the following discussion 

refers to some values that are not in Table E-8. This is because these data were not below 

the toxicity reference value. 

Endosulfan: Freshwater Invertebrate LC50s

n = 89

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

0.001 0.01 0.1 1 10 100 1000 10000 100000

LC50 (ug/L)

Probability Rank

Figure E-2. Plot of the freshwater invertebrate endosulfan acute data. 

One study conducted in Louisiana (USA) calculated the LC50 values for five different 

commercial pesticides, including Thiodan (33.7% endosulfan in xylene) using field 

collected microcrustaceans (Naqvi and Hawkins 1989—ECOTOX reference number 

786). The LC50 values ranged from 0.1 to 0.9 μg/L. The organisms were exposed as a 

community within which only four groups were identified, and only to genus level —

Diaptomus, Eucyclops, Alonella and Cypria. Because we cannot be certain that each of 

these genera represent only one species, and because we cannot be certain about the type 

and number of other organisms present in the exposure medium, these data were not 

considered in the risk assessment. 

Two other studies with values below the toxicity reference value, also were not used. One 

was eliminated because the author did not identify the source of endosulfan used 

(Magadza 1983—ECOTOX reference number 11147). Magadza presented LC50 values 

for four different invertebrates, and the 48 h value for Daphnia longispina was 0.30 μg/L. 

The other unused study (Pandian et al. 2000—ECOTOX reference number 93239) tested 

several pesticides, including Thiokill (35% endosulfan) using three different immature 

stages of the mosquito Culex quinquefasciatus. The LC50 values were 0.0021, 472 and 

4509 μg/L for the II instar larvae, IV instar larvae and pupae, respectively. The study was 

not used because the authors did not adequately describe the experimental design. The 

number of treatments was not given, and their methods only mention the fourth instar 

when describing the acute tests. However, they present results for three different 

immature stages. 

E-11
Leonard et al. (1999—ECTOX reference number 20012) exposed two mayfly nymphs, 

Jappa kutera and Atalophlebia australis, and larvae of a caddisfly, Cheumatopsyche sp. 

to technical grade endosulfan under static, nonrenewal conditions. Animals were exposed 

to endosulfan in the laboratory using water from the Namoi River, Australia. The 

concentrations of endosulfan were measured at the beginning of each test. Six values for 

the three species ranged from 0.4 to 1.8 μg/L, the upper and lower values of this range 

were caddisfly data. However, the two values for Cheumatopsyche sp. were not used 

since the organism was not identified to species. The next lowest value from this study 

was for the mayfly Atalophlebia australis; however, this value (0.6 μg/L) also is 

considered unacceptable. A later study (Hose et al. 2003; ECOTOX reference #73404) 

reported LC50 values an order of magnitude less sensitive for test using Atalophlebia 

spp. Correspondence with one of the coauthors from both studies (Ross V. Hyne, 

personal communication) clarified the difference in sensitivity. Hyne indicated that the 

animals from the first study (Leonard et al. 1999) were likely stressed due to handling 

and transportation prior to the laboratory tests. This situation was corrected before the 

second study. Additional data are provided for Jappa kutera comparing its sensitivity to 

different forms of endosulfan (Leonard et al. 2001—ECOTOX reference number 62479). 

These forms included α and β endosulfans, a technical grade (7:3 ratio of α and β), and 

endosulfan sulfate. The two highest concentrations in the series used for each experiment 

were measured. The 96 hr LC50s were 0.7, 2.3, 1.8 and 1.2 μg/L, respectively. 

Two species of invertebrates were tested in beakers or cages held in flow-through 

artificial streams, the shrimp Paratya australiensis and the mayfly, Jappa kutera (Hose 

and Wilson 2005—ECOTOX reference number 103213). The LC50s using technical 

grade endosulfan were 0.96 and 0.51 μg/L for P. australiensis (two experiments), and 

3.10 μg/L for J. kutera. Although not stated in the paper, the authors refer to earlier work 

for the specific methods. That earlier work indicated that the exposure concentrations 

were verified based on measured values. However, both LC50 values for P. australiensis

are lower than the lowest measured test concentration—therefore these two tests can only 

be used qualitatively. 

Three additional species of freshwater shrimp were tested in three separate studies. 

Juveniles of Palaemonetes paludosus were tested in a 96 hr renewal assay (renewed 

every 24 hr). The LC50 was 0.24 μg/L; however, the concentrations were not measured 

and the source of the endosulfan was not reported (Kamthe 2002—ECOTOX reference 

number 93458). Adults of the tropical freshwater shrimp, Caridina laevis, were tested for 

acute toxicity using a variety of commercial pesticides (Sucahyo et al. 2008—ECOTOX 

reference number 100785), including Thiodan 35EC (35% endosulfan). Exposures were 

static without renewal, and test results were expressed based on concentrations of the 

active ingredient. The 96 hr LC50 for endosulfan was 1.02 μg/L; however, the 

concentrations were not measured. The final LC50 value that was less than the toxicity 

reference value for freshwater invertebrates was for postlarvae of the freshwater prawn

Macrobrachium rosenbergii (Lombardi, et al. 2001—ECOTOX reference number 

61993). The exposure was to a commercial preparation (Thiodan CE); however, the 

nominal exposure concentrations were prepared based on a calculated amount of active 

ingredient. The static, nonrenewal 96 hr LC50 was 0.93 μg/L and the LC50 from a 96 hr 

renewal test (renewed every 24 hr) was 0.20 μg/L. These results; however, are based on 

unmeasured concentrations. 

E-12
Table E-8. Summary of freshwater invertebrate acute data from EPA’s ECOTOX 

database that was less than the toxicity reference value of 2.3 μg/L. The shaded row 

is the value to be used for the risk assessment.

Chemical Name Genus Species Common Name Dur 

(da) 

LC50 

(ug/L) 

% 

a.i. Ref # Comment 

Endosulfan Alonella sp. Water flea 2 0.2 100 786 supplemental 

Endosulfan Atalophlebia australis Mayfly 3 0.6 96 20012 invalid 

Endosulfan Atalophlebia australis Mayfly 2 0.7 96 20012 invalid 

Endosulfan Caridina laevis Smooth Caridina 4 1.02 100 100785 supplemental 

Endosulfan Cheumatopsyche sp. Caddisfly 2 0.4 96 20012 invalid 

Endosulfan Cheumatopsyche sp. Caddisfly 2 1.8 96 20012 invalid 

Endosulfan Culex quinquefasciatus Southern house 

mosquito 1 0.0021 35 93239 supplemental 

Endosulfan Cypria sp. Ostracod 2 0.9 100 786 supplemental 

Endosulfan Daphnia longispina Water flea 2 0.3 100 11147 supplemental 

Endosulfan Diaptomus sp. Calanoid copepod 2 0.6 100 786 supplemental 

Endosulfan Eucyclops sp. Cyclopoid copepod 2 0.1 100 786 supplemental 

Endosulfan Jappa kutera Mayfly 4 0.7 100 62479 supplemental 

Endosulfan Jappa kutera Mayfly 3 1 96 20012 invalid 

Endosulfan Jappa kutera Mayfly 4 1.2 96 20012 invalid 

Endosulfan 

sulphate Jappa kutera Mayfly 4 1.2 100 62479 supplemental 

Endosulfan Jappa kutera Mayfly 4 1.8 100 62479 supplemental 

Endosulfan Macrobrachium rosenbergii Giant river prawn 4 0.2 100 61993 supplemental 

Endosulfan Macrobrachium rosenbergii Giant river prawn 4 0.93 100 61993 supplemental 

Endosulfan Palaemonetes paludosus Riverine grass 

shrimp 4 0.24 100 93458 supplemental 

Endosulfan Paratya australiensis Shrimp 2 0.51 96 103213 supplemental 

Endosulfan Paratya australliensis Shrimp 2 0.96 96 103213 supplemental 

IV. Chronic Toxicity to Freshwater Invertebrates 

Submitted Data for Freshwater Invertebrate Chronic Values 

A freshwater aquatic invertebrate life-cycle test using the TGAI is required for 

endosulfan since the end-use product is expected to be transported to water from the 

intended use site, and the acute EC50 is less than 1 mg/L. The preferred test species is 

Daphnia magna. The lowest observed effect concentration in daphnia (Daphnia magna) 

exposed to technical grade endosulfan was less than 7.0 μg/L (Table E-9). The study 

examined the effects of endosulfan on three consecutive generations of daphnids and 

noted that the poor survival of third generation in the control and the lowest treatment 

group (2.7 μg/L) precluded drawing valid conclusions about the cumulative effects of 

exposure. However, the effects guidelines for a daphnid chronic toxicity test (OPPTS 

850.1300) states that the duration is 21 days. Therefore, we can evaluate the first 

generation exposure (22 days) as a single test. The 2nd and 3rd generations in the original 

test were started by culling out 10 adult daphnids per replicate—making cumulative 

survival difficult to evaluate. It is noteworthy that the NOEC estimate for daphnids (2.7 

E-13
μg/L) is similar to the acute toxicity estimate for stoneflies (2.3 μg/L) and does not 

provide a meaningful estimate of protection for freshwater invertebrates. However, the 

acute to chronic ratio for daphnids (LC50/NOEC: 166/2.7) could be used to predict the 

NOEC for the most sensitive species, the mayfly, Jappa kutera based on its LC50 (0.7 

ug/L). The result of this calculation is a predicted NOEC of 0.011 μg/L for mayflies. The 

chronic invertebrate toxicity testing requirement (Guideline 72-4) is fulfilled (MRID 

5008271). 

Table E-9. Freshwater aquatic invertebrate life-cycle toxicity test using endosulfan 

Species % ai 

21-day 

NOEC/LOEC 

(μg/L) 

Endpoints 

Affected 

MRID No. 

Author/Year 

Study 

Classification 

Waterflea 

(Daphnia 

magna) 99 

NOEC = 2.7 

LOEC= 7.0 

reduced 

survival 

5008271/Macek 

et al. 1976 acceptable 

Mayfly 

(Jappa kutera -- 

NOEC = 

0.011a -- -- -- a

 Predicted based on acute LC50 for J. kutera (0.7 ug/L).divided by the acute to chronic ratio of 61.5 for 

daphnids (LC50/NOEC = 166/2.7). 

Sediment Toxicity 

Endosulfan sulfate sediment toxicity tests were conducted for the midge, Chironomus 

tentans, in two studies. The 20-day NOAEC and LOAEC determined from pore water 

were measured as 0.43 and 1.3 μg/L, respectively, based on mortality (MRID 47318101). 

In a second study classified as supplemental, the most sensitive NOAEC and LOAEC 

were determined as 2.7 and 3.8 μg/L, respectively based on growth (MRID 46382605). 

Additional Open Literature Information (ECOTOX) for Freshwater Invertebrate Chronic 

Values 

There were only two papers from which growth or reproduction effects values were 

potentially lower than the toxicity reference value for freshwater invertebrates (0.037 

μg/L). Both papers, however, were not used. The first paper (Pollino and Holdway 

1999—ECOTOX reference number 20380) evaluated the acute and chronic effect of 

technical grade endosulfan on two species of hydra. The units for the chronic values 

presented in the authors’ Table 2 were apparently mislabeled. The table shows NOEC 

values of 0.04 and 0.06 μg/L; however, based on their Figure 2 and the text the units 

should have been mg/L. The actual NOEC values would therefore be 40 and 60 μg/L, and 

not below the toxicity reference value. 

The second paper evaluated the effect of endosulfan on the growth of juvenile 

Palaemonetes argentinus (Montagna and Collins 2007—ECOTOX reference number 

101421). The test concentrations were not measured, and the size increase was similar for 

both the control and the treatment groups during four molt cycles. The authors report that 

there is a significant relationship between the cephalothorax length for the premolt and 

postmolt stages; however Table 2 is potentially misleading and may give the erroneous 

E-14
idea that there were significant differences between the controls and the treatments, 

which there were not. 

V. Acute Toxicity to Estuarine/marine Fish 

Submitted Data for Estuarine/marine Fish Acute Values

Acute toxicity testing with estuarine/marine fish using the TGAI is required for 

endosulfan because the end-use product is expected to reach this environment because of 

its use in coastal counties. The preferred test species is sheepshead minnow. Acute 

toxicity estimates for marine/estuarine fish ranged from 0.09 μg/L to 0.38 μg/L (Table E10); spot (Leiostomus xanthurus) was the most sensitive (LC50 = 0.09 μg/L) species 

tested. Based on these data, endosulfan is categorized as very highly toxic to 

marine/estuarine fish following an acute exposure. The acute toxicity testing requirement 

using estuarine/marine fish (Guideline 72-3) is fulfilled (MRID 5005824). 

Table E-10. Summary of estuarine/marine fish acute toxicity data submitted by 

registrant for endosulfan 

Species/Static 

or Flow-through % ai 96-hour LC50 (μg/L) 

Toxicity 

Category 

MRID No./ 

Author Year 

Study 

Classification 

Striped Bass 

(Morone saxatilis) --- <1000 --- 05000819/Korn& Earnest 1974 supplemental 

Striped Bass 

(Morone saxatilis) 96 0.1 very highly toxic 

00001328/Earnest 

1970 supplemental 

Striped Mullet 

(Mugil cephalis) Flowthrough 

96 0.38 very highly 

toxic 

5005824/ 

Schimmel et al. 

1977 

acceptable 

Pinfish 

(Lagodon rhomboides) 

Flow-through 

96 0.30 very highly 

toxic 

5005824/ 

Schimmel et al. 

1977 

acceptable 

Spot 

(Leiostomus 

xanthurus) Flowthrough 

96 0.09 very highly 

toxic 

5005824/ 

Schimmel et al. 

1977 

acceptable 

Acute toxicity of endosulfan sulfate was tested on the sheepshead minnow and resulted in 

a 96-hr LC50 of 3.1 μg/L (MRID 46382603). 

Additional Open Literature Information (ECOTOX) for Estuarine/marine Fish Acute 

Values 

All of the open literature values from EPA’s ECOTOX database for estuarine/marine fish 

are presented in Table D-3 of Appendix D. There were no additional chronic values 

available from the ECOTOX database that were less than the estuarine/marine acute 

toxicity reference value (0.09 μg/L). However, there are LC50 values available for the 

preferred test species, the sheepshead minnow Cyprinodon variegatus. These data are 

from an interlaboratory comparison of acute toxicity tests (Schimmel 1981—ECOTOX 

reference # 3740) and are displayed in Table E-11. 

Table E-11. Summary of estuarine/marine acute data from EPA’s ECOTOX 

database for the fish (Cyprinodon variegatus). 

E-15
Chemical 

Name Genus Species Common Name Dur (d) 

LC50 

(ug/L) 

% 

a.i. 

Ref 

# Comment 

Endosulfan Cyprinodon variegatus Sheepshead 

minnow 4 0.34 100 3740 supplemental: measured 

Endosulfan Cyprinodon variegatus Sheepshead 

minnow 4 0.6 100 3740 supplemental: measured 

Endosulfan Cyprinodon variegatus Sheepshead 

minnow 4 0.83 100 3740 supplemental: measured 

Endosulfan Cyprinodon variegatus Sheepshead 

minnow 4 0.88 100 3740 supplemental: measured 

Endosulfan Cyprinodon variegatus Sheepshead 

minnow 4 1.1 100 3740 supplemental: measured 

Endosulfan Cyprinodon variegatus Sheepshead 

minnow 4 1.15 100 3740 supplemental: measured 

Endosulfan Cyprinodon variegatus Sheepshead 

minnow 4 1.2 100 3740 supplemental 

Endosulfan Cyprinodon variegatus Sheepshead 

minnow 4 1.4 100 3740 supplemental 

Endosulfan Cyprinodon variegatus Sheepshead 

minnow 4 2.7 100 3740 supplemental 

Endosulfan Cyprinodon variegatus Sheepshead 

minnow 4 2.81 100 3740 supplemental 

Endosulfan Cyprinodon variegatus Sheepshead 

minnow 4 2.87 100 3740 supplemental 

Endosulfan Cyprinodon variegatus Sheepshead 

minnow 4 3.45 100 3740 supplemental 

VI. Chronic Toxicity to Estuarine/marine Fish 

An estuarine/marine fish early life-stage toxicity test using the TGAI is required for 

endosulfan because the end-use product is expected to be transported to this environment 

from the intended use site and the aquatic acute LC50 is less than 1 mg/L. The preferred 

test species is sheepshead minnow. No sheepshead minnow chronic data were submitted 

by the registrant; however, there are data from the ECOTOX database (Hansen and Cripe 

1991—ECOTOX reference # 14143). These data are a summary of a 7-lab 

interlaboratory comparison of the early life-stage toxicity test using Cyprinodon 

variegatus (Table E-12). All of the tests were flow-through with measured concentration 

of endosulfan. The toxicant used was a technical grade mixture of 64% α-endosulfan and 

36% β-endosulfan. The chronic toxicity data requirement for estuarine/marine fish 

(Guideline 72-4) is fulfilled. It is noteworthy that the NOEC estimate for sheepshead 

minnows (geomean = 0.36 μg/L) is greater than the acute toxicity estimate for spot (0.09 

μg/L) and does not provide a meaningful estimate of protection for estuarine/marine fish. 

However, the acute to chronic ratio for sheepshead minnows can be calculated by 

dividing the geometric mean of the acceptable LC50 values by the geometric mean of the 

chronic values (0.76/0.38). This ratio can be used to predict the NOEC for the most 

sensitive species, the spot, Leiostomus xanthurus. The result of this calculation is a 

predicted NOEC of 0.045 μg/L for spot. 

Table E-12. Estuarine/marine early life-stage tests (28 da) for endosulfan (ECOTOX 

reference # 14143). 

E-16
Species NOEC (μg/L) LOEC (μg/L) Endpoint Study 

Classification 

Sheepshead minnow 

(Cyprinodon variegates) 0.50 0.92 growth supplemental: measured 

Sheepshead minnow 

(Cyprinodon variegates) 0.31 0.54 growth supplemental: measured 

Sheepshead minnow 

(Cyprinodon variegates) 0.30 0.55 survival supplemental: measured 

Sheepshead minnow 

(Cyprinodon variegates) 0.29 0.47 growth supplemental: measured 

Sheepshead minnow 

(Cyprinodon variegates) 1.2 2.6 survival supplemental: measured 

Sheepshead minnow 

(Cyprinodon variegates) 0.21 0.41 survival supplemental: measured 

Sheepshead minnow 

(Cyprinodon variegates) 0.62 1.2 survival supplemental: measured 

Sheepshead minnow 

(Cyprinodon variegates) 0.58 1.2 survival supplemental: measured 

Sheepshead minnow 

(Cyprinodon variegates) 0.17 0.43 growth supplemental: measured 

Sheepshead minnow 

(Cyprinodon variegates) 0.27 0.75 survival supplemental: measured 

Spot 

(Leiostomus xanthurus) 0.043a -- -- -- 

a

 Predicted based on acute to chronic ratio for sheepshead minnow (LC50/NOEC = 0.76/0.38) 

VII. Acute Toxicity to Estuarine/marine Invertebrates 

Submitted Data for Estuarine/marine Invertebrate Acute Values 

Acute toxicity testing with estuarine/marine invertebrates using the TGAI is required for 

endosulfan because the end-use product is expected to reach this environment because of 

its use in coastal counties. The preferred test species are mysid shrimp and eastern oyster. 

There was considerable variability in toxicity estimates for estuarine/marine invertebrates 

exposed to technical grade endosulfan. Estimated EC50 values ranged from 0.04 μg/L to 

790 μg/L and represented a difference of four orders of magnitude (Table E-13). Based 

on the most sensitive EC50 (0.04 μg/L) for pink shrimp, endosulfan is classified as very 

highly toxic to marine invertebrates. The estuarine/marine acute toxicity testing 

requirement (Guidelines 72-3b and 72-3c) is fulfilled (MRID 128688, 5005824). 

Table E-13 Summary of acute estuarine/marine invertebrate toxicity data submitted 

by the registrant for endosulfan. 

Species/Static or 

Flow-through % ai. 96-hour EC50 (μg/L)) 

Toxicity 

Category 

MRID No. 

Author/Year 

Study 

Classification

Eastern oyster 

(Crassostrea virginica)

static embryo-larvae 

96 0.45 very highly toxic 128688/Boeri& 

Ward/1983 supplemental 

Fiddler crab 

(Uca pugnax) static 96 790 highly toxic 128688/Boeri& Ward 1983 supplemental 

Grass shrimp

(Palaemonetes pugio)

Flow-through 

96 1.31 very highly toxic 

5005824/ 

Schimmel et al. 

1977 

acceptable 

Pink Shrimp 96 0.04 very highly toxic 5005824/ acceptable 

E-17
Species/Static or 

Flow-through % ai. 96-hour EC50 (μg/L)) 

Toxicity 

Category 

MRID No. 

Author/Year 

Study 

Classification

(Penaeus duorarum)

Flow-through 

Schimmel et al. 

1977 

Acute toxicity of endosulfan sulfate was tested on the mysid shrimp and resulted in a 96-

hr LC50 of 7.9 μg/L, which is considered very highly toxic (MRID 46406401). 

Comparison among the mysid shrimp toxicity for endosulfan sulfate and the grass shrimp 

toxicity for the parent compound suggest the parent isomer is more toxic than the 

degradate. 

Acute toxicity testing using technical end product (48% a.i.) on brown shrimp resulted in 

a 96-hr toxicity estimate of 0.24 μg/L (Earnest 1970; Accession Number 00001328). 

Based on these data, technical end product is categorized as very highly toxic to 

estuarine/marine invertebrates. 

Additional Open Literature Information (ECOTOX) for Estuarine/marine Invertebrate 

Acute Values 

In addition to the aforementioned acute mortality studies with estuarine/marine 

invertebrates, an additional study was identified in the open literature which reported 

several LC50 values for mysids (Americamysis bahia; Schimmel 1981—ECOTOX 

reference # 3740). This study reported the results of an interlaboratory comparison of 

acute toxicity tests using estuarine animals. There were five acute LC50 values based on 

measured, flow-through tests ranging from 0.38 to 1.29 μg a.i./L (see Table E-14). While 

none of these values is lower than the LC50 for the pink shrimp listed above, their 

geometric mean (0.83 μg a.i./L) will be used to establish the acute to chronic toxicity 

ratio for estuarine/marine invertebrates used in the next section. 

Table E-14. Summary of estuarine/marine acute data from EPA’s ECOTOX 

database for the mysid shrimp Americamysis bahia.

Chemical 

Name Genus Species Common Name 

Dur 

(d) 

LC50 

(ug/L) 

% 

a.i. 

Ref 

# Comment 

Endosulfan Americamysis bahia mysid shrimp 4 0.38 NR 3740 supplemental: 

measured 

Endosulfan Americamysis bahia mysid shrimp 4 0.75 NR 3740 supplemental: 

measured 

Endosulfan Americamysis bahia mysid shrimp 4 0.94 NR 3740 supplemental: 

measured 

Endosulfan Americamysis bahia mysid shrimp 4 1.16 NR 3740 supplemental: 

measured 

Endosulfan Americamysis bahia mysid shrimp 4 1.29 NR 3740 supplemental: 

measured 

Endosulfan Americamysis bahia mysid shrimp 4 0.24 NR 3740 supplemental 

Endosulfan Americamysis bahia mysid shrimp 4 0.46 NR 3740 supplemental 

Endosulfan Americamysis bahia mysid shrimp 4 0.73 NR 3740 supplemental 

Endosulfan Americamysis bahia mysid shrimp 4 1.12 NR 3740 supplemental 

Endosulfan Americamysis bahia mysid shrimp 4 1.47 NR 3740 supplemental 

E-18
VIII. Chronic Toxicity to Estuarine/marine Invertebrates 

An estuarine/marine invertebrate life-cycle toxicity test using the TGAI is required for 

endosulfan because the end-use product may be applied directly to the estuarine/marine 

environment or is expected to be transported to this environment from the intended use 

site, and the following conditions are met: (1) the pesticide is intended for use such that 

its presence in water is likely to be continuous or recurrent regardless of toxicity, (2) any 

aquatic acute LC50 or EC50 is less than 1 mg/L, (3) the EEC in water is equal to or 

greater than 0.01 of any acute LC50 or EC50 value, or, (4) the actual or estimated 

environmental concentration in water resulting from use is less than 0.01 of any acute 

LC50 or EC50 value and any of the following conditions exist: studies of other organisms 

indicate the reproductive physiology of fish and/or invertebrates may be affected, 

physicochemical properties indicate cumulative effects, or the pesticide is persistent in 

water (e.g., half-life greater than 4 days). No valid chronic data for estuarine/marine 

invertebrates exposed to technical endosulfan were submitted by the registrant. However, 

there are data from the ECOTOX database (McKenney 1982—ECOTOX reference # 

3736). These data are a summary of an interlaboratory comparison of the early life-stage 

toxicity test using Americamysis bahia—formerly Mysidopsis bahia (Table E-14). All of 

the tests were flow-through with measured concentration of technical endosulfan. The 

chronic toxicity data requirement for estuarine/marine invertebrates (Guideline 72-4) is 

fulfilled. It is noteworthy that the NOEC estimate for mysid shrimp (geomean = 0.27 

μg/L) is greater than the acute toxicity estimate for pink shrimp (0.04 μg/L) and does not 

provide a meaningful estimate of protection for estuarine/marine invertebrates. However, 

the acute to chronic ratio for mysids can be calculated by dividing the geometric mean of 

the acceptable LC50 values (Table E-15 by the geometric mean of the chronic values 

(0.83/0.27). This ratio can be used to predict the NOEC for the most sensitive species, the 

pink shrimp, Penaeus duorarum. The result of this calculation is a predicted NOEC of 

0.013 μg/L for spot. 

Table E-15. Estuarine/marine invertebrate chronic tests for endosulfan (ECOTOX 

reference # 3736). 

Species NOEC 

(μg/L) 

LOEC 

(μg/L) Endpoint Affected Study Classification 

Mysid shrimp 

(Americamysis bahia) 0.33 0.71 survival/ reproduction 

supplemental: 

measured 

Mysid shrimp 

(Americamysis bahia) 0.52 1.12 survival supplemental: measured 

Mysid shrimp 

(Americamysis bahia) 0.14 0.31 survival supplemental: measured 

Mysid shrimp 

(Americamysis bahia) 0.28 0.60 survival supplemental: measured 

Mysid shrimp 

(Americamysis bahia) 0.22 0.28 survival supplemental: measured 

Pink shrimp 

(Penaeus duorarum) 0.013a -- -- -- 

a

 Predicted based on acute to chronic ratio for mysid shrimp (LC50/NOEC = 0.83/0.27) 

E-19
Chronic exposure to endosulfan sulfate was conducted for the mysid shrimp. The 

NOAEL and LOAEL were 0.38 and 0.73 μg/L, respectively and the most sensitive 

endpoint was growth (MRID 46781601). 

Endosulfan sulfate sediment toxicity tests were conducted for the estuarine amphipod, 

Leptocheirus plumulosus, in two studies (Table E-16). The 10-day NOAEC and LOAEC 

determined from pore water were measured as 27 and 45 μg/L, respectively, based on 

mortality (MRID 46382606). In a 28-day study, the most sensitive NOAEC and LOAEC 

were determined as 1.58 and 4.0 μg/L, respectively based on growth (MRID 46929001). 

Table E-16. Toxicity of Endosulfan Sulfate to Aquatic Organisms Through 

Sediment Exposure. 

Test Species 

Exposure 

Duration Endpoint (a)

Pore 

Water 

(μg ai/L) 

Bulk 

Sediment 

(mg ai/kg dw) 

Study Classification 

(MRID) 

Estuarine Amphipod, 

Leptocheirus 

plumulosus

10-d 

Survival: 

EC50

LOAEC 

NOAEC 

74 

45 

27 

2.3 

1.6 

0.86 

Supplemental 

(46382606) 

Estuarine Amphipod, 

Leptocheirus 

plumulosus

28-d 

Growth: 

EC50

LOAEC 

NOAEC 

>4.0 

4.0 

1.58 

>1.2 

1.2 

0.48 

Supplemental 

(46929001) 

(a) information for the most sensitive endpoint is presented. 

IX. Toxicity to Aquatic-phase Amphibians 

A number of studies involving amphibian toxicity testing and endosulfan were identified 

in the open literature and are summarized below. None of these studies provide reliable 

estimates of toxicity that may be used quantitatively in this risk assessment; however, 

they do provide some information regarding the hazard of endosulfan to amphibians. 

Although only supplemental information is available for aquatic-phase amphibians, it 

appears that freshwater fish are substantially more sensitive. 

Bernabò, et al. (2008—ECOTOX reference # 103223) and Brunelli, et al. (2009) 

evaluated the effect of endosulfan (99% purity) on tadpoles of the common toad Bufo 

bufo. Four-day-old tadpoles were exposed for 96 hr in a static test. The 96 hr LC50 value 

based on nominal concentrations was 430 μg/L (Bernabò, et al. (2008). In a separate test, 

exposure to 200 μg/L endosulfan resulted in an apparent increase in mucus production by 

the gills, as well as inflammation of the gills. These changes occurred after only 24 hr and 

became more pronounced as the exposure continued (Bernabò, et al. 2008). The same 

group continued their work with endosulfan and this toad species looking for behavior 

and morphological differences (Brunelli, et al. 2009). Three concentrations and a control 

were used. There were no statistically significant differences between the control and 10 

μg/L for survival, the rate of deformity or the number of toads metamorphosed (into 

Gosner stage 46—complete tail resorption). However, there was 77% and 97% mortality 

at 50 and 100 μg/L, respectively. In addition, 100% of the surviving tadpoles exhibited 

various degrees of deformity and none of the survivors reach stage 46. 

E-20
Several papers evaluated the effect of endosulfan on tadpoles of Australian frogs, but all 

were unmeasured tests. Broomhall (2002—ECOTOX reference # 65732) exposed 

tadpoles of Litoria citropa to a single 0.8 μg/L nominal concentration of endosulfan 

(Thiodan) under two different temperature regimes, one more variable than the other over 

the 96 hr test. At ambient temperatures (ca. 20 C) the survival was 89% in the endosulfan 

treatment (100% in the control). Under a similar average temperature, but more variable, 

only 58% of the tadpoles survived, compared to 92% in the controls. After termination of 

the above test, all surviving tadpoles were transferred to clean water and held at 19 C for 

24 days. These tadpoles were then evaluated for their ability to avoid predation by 

odonates. The endosulfan treated animals were more vulnerable to predation, measured 

by a significant decrease in the number of minutes elapsed until capture. 

Broomhall and Shine (2003--ECOTOX reference # 71866) exposed tadpoles of the 

Australian tree frog Litoria freycineta to two different concentrations of endosulfan 

(source not given, but assume was same as Broomhall (2002)—Thiodan). There was no 

effect on survival after 96 hr exposure to 0.03 or 1.3 μg/L a.i. relative to the controls. 

However, exposed tadpoles grew more slowly than controls. And the survivors were 

more vulnerable to odonate (dragon fly larvae) predations when tested 15 days after 

transfer to clean water. Broomall (2004—ECOTOX reference #73400) completed 

another series of experiments similar to the above, using the same exposure 

concentrations with a different species, Limnodynastes peronii, with similar results. 

Canadian frogs were evaluated based on unmeasured concentrations. Green frog eggs and 

larvae (Rana clamitans) were exposed to two different scenarios using Thiodan 50WP 

(Harris, et al. 1998—ECOTOX reference #19300). In the first test series, Gosner stage 8 

embryos through to stage 25 tadpoles were continuously exposed to a treatment for 13 

days (two-thirds renewal of treatment solutions every second day). The 96 hr LC50 was 

greater than the highest concentration tested (11,750 μg/L a.i.); however, the 13 day 

LC50 was 15 μg/L—suggesting that the earlier embryonic stages were not as sensitive to 

endosulfan. Note, hatching occurred around day eight of the test. A second set of 

exposures in this study consisted of the same exposure for the first 4 days, then a period 

of 7.5 days in reference water, followed by a second 4-day exposure to the same 

concentrations. The 96 hr LC50 was again a greater than, and the 16 day LC50 was the 

same as that in the first test. The frequency of deformities at hatch also were calculated in 

the second test, resulting in an EC50 of 2,430 μg/L. 

The toxicity of Thiodan 4EC (40% emulsified concentrate) was evaluated (Berrill et al. 

1998—ECOTOX reference # 19467) with newly hatched and two-week-old tadpoles of 

the wood frog (Rana sylvatica), the American toad (Bufo americanus), and the green frog 

(Rana clamitans). Embryos of the wood frog were also tested, but were not as sensitive 

as tadpoles; therefore embryos of the other two species were not tested. New hatched 

tadpoles of each species were exposed for 96 hr followed by a 10 day recovery/ 

observation period. Two-week of tadpoles were likewise exposed for 96 hr, and followed 

for and additional 7 day recovery period in clean water. Water concentrations of 

endosulfan were measured, but only after the first hour of the exposure period and the 

treatments were apparently not renewed. There was essentially no mortality for either life 

stage for all three species during the first 96 hr; however, there was extensive post 

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exposure mortality. Also, two-week old tadpoles were more sensitive than newly hatched 

tadpoles—no LC50s were calculated. 

Early stage tadpoles of Bufo melaanostictus, Limnonectes limnocharis and Microphyla 

ornata were exposed to a commercial end-use product of endosulfan (35EC) in 96-h 

acute toxicity tests (Dey and Gupta 2002—not in ECOTOX). The authors used 10 

animals per container and three containers per treatment. They did not describe the 

chambers, the volume of water used, or the source of the water. Control mortality also 

was not described. The 96-h LC50s were based on nominal concentrations and are 20, 13 

and 0.16 μg/L, respectively, for the three species listed above. 

Finally, there is a preprint available that evaluates the growth and survival of the northern 

leopard frog Rana pipiens tadpoles (Shenoy et al. in press). They exposed four-day-old 

tadpoles to Endosulfan 3EC (33% a.i.) for seven weeks. Each individual was placed into 

a separate 1.5 L of exposure medium with the water changed every 3 days. There were 15 

individuals used for each treatment. Besides the controls, treatments were 0.2, 1 and 5 

μg/L of the active ingredient. Concentrations were not measured. Growth rate (length) 

was not affected in surviving tadpoles in any treatment relative to the controls. No LC50 

values were calculated; however, there was 100% mortality by day 12 and day 28 in the 5 

and 1 μg/L treatments, respectively. Based on the authors’ Figure 1 the control survival 

was approximately 80% at the end of the seven weeks and that in the 0.2 μg/L treatment 

approximately 40%. Although no 96 hr data were presented, the figure suggests that there 

was little of no mortality during the first 4 days of the experiment. 

X. Toxicity to Aquatic Plants 

There were no data on the toxicity of endosulfan to aquatic vascular or non-vascular 

plants submitted by the registrant. Plant data are generally not required unless the 

toxicant is an herbicide. There were several references available from the open literature: 

however, only one of these could be considered as following methods suitable to be 

considered acceptable (DeLorenzo et al 2002—ECOTOX reference # 65915). This study 

reported the 96 hr EC50 for the green alga Pseudokirchneriella subcapitatum (formerly 

Selenastrum capricoratum) using a standard ASTM protocol. This species is one of the 

preferred species. The EC50 is 428 μg/L based on nominal concentrations of technical 

grade endosulfan (98.6% a.i.). There were no data available for aquatic vascular plants. 

References 

The references that refer to an ECOTOX number can be found in the reference list for 

Appendix D. The references listed below are for the data submitted to the Agency. 

 MRID Aquatic Citation References 

Non-Guideline. Multi-Taxa Studies 

40094602 Johnson, W.; Finley, M. (1980) Handbook of Acute Toxicity of Chemicals to Fish and 

Aquatic Invertebrates: Resource Publication 137. US Fish and Wildlife Service, Washington, 

D.C. 106 p 

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40098001 Mayer, F.; Ellersieck, M. (1986) Manual of Acute Toxicity: Inter- pretation and Data Base for 

410 Chemicals and 66 Species of Freshwater Animals. US Fish & Wildlife Service, Resource 

Pub- lication 160. 579 p. 

5008271 Macek, K.J.; Lindberg, M.A.; Sauter, S.; Buxton, K.S.; Costa, P.A. (1976) Toxicity of Four 

Pesticides to Water Fleas and Fathead Minnows. Duluth, Minn.: U.S. Environmental 

Protection Agency, Environmental Research Laboratory. (EPA report no. EPA-600/3-76-099; 

available from: NTIS, Springfield, VA; PB-262 912) 

Guideline 72-1. Acute Toxicity to Freshwater Fish 

BA007903 U.S. EPA (1976) Report on the toxicity of thiodan to bluegill sunfish. U.S. EPA Chemical 

and Biological Investigations Branch, Beltsville, Maryland, static jar test No. 1023, 

unpublished report, 1976. 

BA007902 U.S. EPA (1976) Report on the toxicity of thiodan to rainbow trout. U.S. EPA Chemical and 

Biological Investigations Branch, Beltsville, Maryland, static jar test No. 1033, unpublished 

report, 1976. 

33020 Ludeman, J.A. (1972)Fish toxicity laboratory report, rainbow trout (Salmo gairdnerii) Test 

No. 496, I.D. Number 10033, USDA Reg. No. 70-126, Product name Kill-Ko Thiodan, 

Producer name, Rigo manufacturing Company, ARS-PR, ARC, Animal Biology Laboratory, 

Beltsville. 

38806 Buccafusco, R.J. (1976) Acute Toxicity of Endosulfan Technico to Bluegill (Lepomis 

macrochirus). (Unpublished study received Jul 28, 1980 under 2749-487; prepared by 

EG&G, Bionomics, sub- mitted by Aceto Chemical Co., Inc., Flushing, N.Y.; CDL: 243084-

A) 

73120 Johnson, W.W. (1973) Letter sent to Robert E. Hawk dated Jul 12, 1973. Data for ethion and 

thiodan. (U.S. Fish and Wildlife Service, Fish-Pesticide Research Laboratory; unpublished 

study; CDL:120619-L) 

101350 Ludemann, D.; Neumann, H. (1960) Versuche uber die akute toxische wirkung neuzeitlicher 

kontaktinsektizide auf einsommerigc karpfen (Cyprinus carpio L.). Z. Angew Zool. 47(1):11-

33. (German text; also In unpublished submission received Nov 1, 1970 under unknown 

admin. no.; submitted by Hercules, Inc., Agricultural Chemicals, Wilmington, DE; 

CDL:005103-X) 

109703 Oeser, H.; Gorbach, S.; Knauf, W. (1971) Endosulfane and the environment. Pages 17-22, In 

Giornate Fitopathologie, May, 1971, Udine, Italy. (S.l.:s.n.). (Also In unpublished submission received Nov 1, 1973 under 3F1314; submitted by FMC Corp., Middleport, NY; 

CDL:094299-L) 

115694 U.S. Fish and Wildlife Service, Fish-Pesticide Research Laboratory (19??) Toxicity of Ethion 

and Thiodan to Freshwater Fish. (Un- published study; CDL:248580-L) 

128655 Kintner, D.; Forbis, A. (1983) Acute Toxicity of Thionex 3 EC to Rainbow Trout ...: Static 

Bioassay Report #29975. (Unpublished study received May 31, 1983 under 11678-25; 

prepared by Analyti- cal Bio-Chemistry Laboratories, Inc., submitted by Makhteshim BeerSheva Chemical Works, Ltd., New York, NY; CDL:250401-A) 

128656 Kintner, D.; Forbis, A. (1983) Acute Toxicity of Thionex 3 EC to Bluegill Sunfish Static 

Bioassay Report #29974. (Unpublished study received May 31, 1983 under 11678-25; 

prepared by Analytical Bio-Chemistry Laboratories, Inc., submitted by Makh- teshim BeerSheva Chemical Works, Ltd., New York, NY; CDL: 250401-B) 

E-23
136999 Fischer, R. (1983) The Effect of Hoe 002671 OI ZD96 0002 (Endosulfan, Active Ingredient 

95.9%) on Salmo gairdneri (Rainbow Trout) in a Static Test: OEK83/019E; Document 

#A26006. (Unpublished study received Dec 27, 1983 under 8340-13; prepared by Hoechst 

AG, W. Ger., submitted by American Hoeschst Corp., Somerville, NJ; CDL:252043-G) 

148833 Turner, W.; Khalifa, S.; Casida, J. (1975) Toxaphene toxicant A. Mixture of 2,2,5-endo,6-

exo,8,8,9,10-octachlorobornane and 2,2,5-endo,6-exo,8,9,9,10-octachlorobornane. J. Agric. 

Food Chem. 23(5):991-994. 

151765 Kintner, D.; Forbis, A. (1983) Acute Toxicity of Thionex 50 WP to Rainbow Trout (Salmo 

gairdneri): Static Bioassay Report #29977. Unpublished report prepared by Analytical Biochemistry Labora- tories, Inc. 59 p. 

151766 Kintner, D.; Forbis, A. (1983) Acute Toxicity of Thionex 50 WP to Bluegill Sunfish 

(Lepomis macrochirus): Static Bioassay Report # 29976. Unpublished report prepared by 

Analytical Bio-chemistry Laboratories, Inc. 57 p. 

250401A Kintner, D.; Forbis, A. (1983) Acute Toxicity of Thionex 50 WP to Rainbow Trout (Salmo 

gairdneri): Static Bioassay Report #29977. Unpublished report prepared by Analytical Biochemistry Laboratories, Inc. 59 p. 

5003103 Amminikutty, C.K.; Rege, M.S. (1977) Effects of acute and chronic exposure to pesticides, 

Thiodan E_C_ 35 and Agallol '3' on the liver of widow tetra, Gymnocorymbus ternetzi 

(Boulenger). Indian Journal of Experimental Biology 15(3):197-200. 

5003107 Macek, K.J.; Hutchinson, C.; Cope, O.B. (1969) The effects of temperature on the 

susceptibility of bluegills and rainbow trout to selected pesticides. Bulletin of Environmental 

Contamination and Toxicology 4(3):174-183. 

5003351 Reddy, T.G.; Gomathy, S. (1977) Toxicity and respiratory effects of pesticide, Thiodan on 

catfish, Mystus vittatus. Indian Journal of Environmental Health 19(4):360-363. 

5004792 Basak, P.K.; Konar, S.K. (1976) Toxicity of six insecticides to fish. Geobios 3(6): 209-210. 

5008271 Macek, K.J.; Lindberg, M.A.; Sauter, S.; Buxton, K.S.; Costa, P.A. (1976) Toxicity of Four 

Pesticides to Water Fleas and Fathead Minnows. Duluth, Minn.: U.S. Environmental 

Protection Agency, Environmental Research Laboratory. (EPA report no. EPA-600/3-76-

099; available from: NTIS, Springfield, VA; PB-262 912) 

5014941 Pickering, Q.H.; Henderson, C. (1966) The acute toxicity of some pesticides to fish. Ohio 

Journal of Science 66(5):508-513. 

45202909 Grande, M.; Andersen, S.; Berge, D. (1994) Effects of pesticides on fish: experimental and 

field studies. Norwegian Journal of Agricultural Sciences Suppl. 13: 195-209. 

45421402 Gries, T.; van der Kolk, J. (2000) (Carbon 14) Endosulfan sulfate (metabolite of (Carbon 14-

Endosulfan) Acute Toxicity Test with Carp (Cyprinus carpio) under Static Conditions: Lab 

Project Number: 1049.014.170: C010869. Unpublished study prepared by Springborn 

Laboratory (Europe) AG. 52 p. 

45538301 Gries, T.; van der Kolk, J. (2000) (Carbon 14)-Endosulfan Sulfate (Metabolite of (Carbon 

14)-Endosulfan): Acute Toxicity Test with Rainbow Trout (Oncorhynchus mykiss) under 

Semi-Static Conditions: Lab Project Number: 1049.014.103: C016132. Unpublished study 

prepared by Springborn Laboratories AG. 54 p. {OPPTS 850.1075} 

46382604 Cafarella, M. (2003) Endosulfan Sulfate - Acute Toxicity to Bluegill Sunfish (Lepomis 

macrochirus) Under Flow-Through Conditions. Project Number: 13798/6127, 

33278/EBENX, B004613. Unpublished study prepared by Springborn Smithers Laboratories. 

53 p. 

Guideline 72-2. Acute Toxicity to Freshwater Invertebrates 

E-24
109704 Knauf, W.; Schulze, E. (1973) New Findings on the Toxicity of Endosulfan and Its Metabolites 

to Aquatic Organisms. (Unpublished study received Nov 1, 1973 under 3F1314; prepared by 

Farbwerke Hoechst AG, W. Ger., submitted by FMC Corp., Middleport, NY; CDL:094299-M) 

134394 Knauf, W.; Schulze, E. (1973) New Findings on the Toxicity of Endosulfan and Its Metabolites 

to Aquatic Organisms. (Unpublished study received Nov 1, 1973 under unknown admin. no.; 

prepared by Farbwerke Hoechst AG, W. Ger., submitted by FMC Corp., Philadel- phia, PA; 

CDL:120346-J) 

45421403 Gries, T.; van der Kolk, J. (2000) (Carbon 14) Endosulfan sulfate (metabolite of (Carbon 14-

endosulfan) Acute Immobilisation Test with Daphnids (Daphnia magna) under Static 

Conditions: Lab Project Number: 1049.014.110: C012413. Unpublished study prepared by 

Springborn Laboratory (Europe) AG. 64 p. 

Guideline 72-3. Acute Toxicity to Estuarine/Marine Organisms 

00001328 Earnest, R. (1970) Annual progress report: 1970 effects of pesticides on aquatic animals in the 

estuarine and marine environment. (Unpublished study received Nov 26, 1976 under 241-132; 

prepared by U.S. Fish and Wildlife Service, fish-Pesticide Research Laboratory, submitted by 

American Cyanamid Co., Princeton, N.J.; CDL: 129448-W). 

128658 Energy Resources Co., Inc. (1983) Acute Toxicity of Endosulfan to Embryos of the Eastern 

Oyster (Crassostrea virginica) and the Fiddler Crab (Uca pugnax). Final rept. (Unpublished 

study received May 31, 1983 under 8340-13; submitted by American Hoechst Corp., 

Somerville, NJ; CDL:250395-B) 

128688 Boeri, R.H. and T.J. Ward. 1983. Acute toxicity of endosulfan to embryos of the eastern oyster 

(Crassostrea virginica) and the fiddler crab (Uca pugnax). Final Report. Submitted by American 

Hoechst Corp., Somerville, N.J.; prepared by Energy Resources Co., Inc., Cambridge, Mass. 

Reg. No. 8340-13. Acc. No. 250395. 

5000819 Korn S.; Earnest, R. (1974) Acute toxicity of twenty insecticides to striped bass Morone 

saxatilis. California Fish and Game, 60 (3); 128-131. 

5003062 Roberts, D. (1975) The effect of pesticides on byssus formation in the common mussel, Mytilus 

edulis. Environmental Pollution 8(4):241-254. 

5005824 Schimmel, S.C.; Patrick, J.M., Jr.; Wilson, A.J., Jr. (1977) Acute toxicity to and 

bioconcentration of endosulfan by estuarine animals. Pages 241-252, in Aquatic Toxicology 

and Hazard Evaluation. Edited by F.L. Mayer and J.L. Hamelink. Philadelphia, Pa.: American 

Society for Testing and Materials. 

46382603 Cafarella, M. (2003) Endosulfan Sulfate - Acute Toxicity to Sheepshead Minnow (Cyprinodon 

variegatus) Under Flow-Through Conditions. Project Number: 13798/6138, EBENX014, 

B004571. Unpublished study prepared by Springborn Smithers Laboratories. 53 p. 

46406401 Cafarella, M. (2003) Endosulfan Sulfate - Acute Toxicity to Mysids (Americamysis bahia) 

Under Flow-Through Conditions. Project Number: 13798/6137, EBENX015, B004570. 

Unpublished study prepared by Springborn Smithers Laboratories. 53 p. 

Guideline 72-4. Fish Early Life Stage/Aquatic Invertebrate Life Cycle Study 

3443 Reinert, H.K.; Parke, G.S.E. (1975) Report: Static 96 Hour Toxicity Study of Mobil Chemical 

Company Sample Modown 4 Lb./Gal. Flowable-M in Bluegill Sunfish and Rainbow Trout. 

(Unpublished study received Dec 12, 1975 under 2224-EX-10; prepared by Cannon 

Laboratories, Inc., submitted by Mobil Chemical Co., Industrial Chemicals, Richmond, Va.; 

CDL:223665-G) 

29544 Pitcher, F. (1972) Kill-Ko Thiodan: Toxicity to Rainbow Trout: Test No. 496. (U.S. 

Agricultural Research Service, Pesticides Regulation Div., Animal Biology Laboratory, 

E-25
unpublished report.) 

33020 Pitcher, F. (1972) Kilt-Ko Thiodan: Toxicity to Rainbow Trout (Salmo gairdneri): Test No. 

496. (U.S. Agricultural Re- search Service, Animal Biology Laboratory, unpublished study.) 

33021 McCann, J.A. (1976) SA-50 Brand Thiodan 50 Wettable Powder: Toxicity to Rainbow Trout 

(Salmo gairdneri). (U.S. Environmental Protection Agency, Animal Biology Laboratory, 

unpublished study.) 

33022 McCann, J.A. (1976) Metadan 2-2: Toxicity to Bluegill (Lepomis macrochirus). (U.S. 

Environmental Protection Agency, Animal Biology Laboratory, unpublished study.) 

38306 Buccafusco, R.J. (1976) Acute Toxicity of Endosulfan Technico to Bluegill (Lepomis 

macrochirus). (Unpublished study received Jul 28, 1980 under 2749-487; prepared by EG&G, 

Bionomics, sub- mitted by Aceto Chemical Co., Inc., Flushing, N.Y.; CDL: 243084-A) 

52151 McCann, J.A. (1976) Thiodan Tech 86%: Toxicity to Rainbow Trout (Salmo garidneri). (U.S. 

Environmental Protection Agency, Animal Biology Laboratory, unpublished study.) 

52152 McCann, J.A. (1976) Thiodan Tech 86%: Toxicity to Bluegill (Lepomis macrochirus). (U.S. 

Environmental Protection Agency, Animal Biology Laboratory, unpublished study.) 

40462201 Graney, R. (1987) Progress Report No. 3: Endosulfan Pond Study. Unpublished study prepared 

by Battelle Columbus Laboratories. 79 p. 

46510701 Heusel, R. (1991) Endosulfan - Substance, Technical (HOE 002671 00 ZD98 0005) Effect to 

Daphnia magna (Waterflea) In a 21-Day Reproduction Test (Method OECD). Project Number: 

CE90/076, A46561. Unpublished study prepared by Endosulfan Task Force. 246 p. 

46781601 Cafarella, M. (2006) Endosulfan Sulfate - Life-Cycle Toxicity Test with Mysids (Americamysis 

bahia). Project Number: EBENM019, 13798/6178. Unpublished study prepared by Springborn 

Smithers Laboratories. 71 p. Relates to L0001048. 

Guideline 72-5. Life cycle fish 

5003103 Amminikutty, C.K.; Rege, M.S. (1977) Effects of acute and chronic exposure to pesticides, 

Thiodan E_C_ 35 and Agallol '3' on the liver of widow tetra Gymnocorymbus ternetzi

(Boulenger). Indian Journal of Experimental Biology 15(3):197-200. 

45868601 Dionne, E. (2002) Endosulfan: The Chronic Toxicity to the Fathead Minnow (Pimephales 

promelas) During Full Life-Cycle Exposure: Lab Project Number: 13726.6140: B004189. 

Unpublished study prepared by Springborn Smithers Laboratories. 142 p. 

Guideline 850.1735 (Draft). Whole sediment acute freshwater invertebrates 

46382605 Putt, A.E. (2004) Endosulfan Sulfate toxicity to midge (Chironomus tentans) during a 10-day 

sediment exposure. Springborn Smithers laboratories, Wareham, MA. Laboratory Report ID 

13798.6142. 

46382606 Putt, A. (2004) Endosulfan Sulfate - Toxicity to Marine Amphipods (Leptocheirus plumulosus) 

During a 10-Day Sediment Exposure. Project Number: 13798/6143, EBENX019, B004782. 

Unpublished study prepared by Springborn Smithers Laboratories. 83 p. 

46929001 Putt, A. (2006) Endosulfan Sulfate - Toxicity to Estuarine Amphipods (Leptocheirus 

plumulosus) During a 28-Day Sediment Exposure. Project Number: 13798/6186, EBENX023. 

Unpublished study prepared by Springborn Smithers Laboratories. 60 p. Relates to L0001083. 

47318101 Weltje, L; Pupp, A. (2008) Endosulfan sulfate – life cycle toxicity testing exposing midges 

(Chironomus tentans) to a test substance applied to sediment under static-renewal conditions 

following EPA test methods. Springborn Smithers Laboratories, Wareham, MA. Laboratory 

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Report ID. 13798.6185. 

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