O,O-diethyl hydrogen phosphorodithioate

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2005

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study fulfiled the criteria of validation as determined by the non-standard guideline.

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: DS/EN ISO 14669 " water quality - determination of acute lethal toxicity to marine copepods (Copopeda, Crustacea)", 1999

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Phosphorodithioic acid, O,O-diethylester, potassium salt

IUPAC Name:

Phosphorodithioic acid, O,O-diethylester, potassium salt

Constituent 2

Reference substance name:

3454-66-8

Cas Number:

3454-66-8

IUPAC Name:

3454-66-8

Details on test material:

- Name of test material (as cited in study report): EP-1, potassium salt (Potassium O,O-diethyl phosphorodithioate)
- Molecular formula (if other than submission substance): C4H10KO2PS2
- Molecular weight (if other than submission substance):224.32 g/mol
- Physical state: white powder
- Analytical purity: 99.7% (w/w)
- Lot/batch No.: 343-BSe-66E
- Storage condition of test material: Test substance was stored at -20°C.

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
PHYSICO-CHEMICAL PROPERTIES
- Water solubility (under test conditions): 80 g/L
- log Pow: -0.46

Sampling and analysis

Analytical monitoring:

not specified

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A stock solution was prepared by dissolving the test substance directly in test medium (filtered clean sea water), from which the test solutions were prepared
- Controls: Filtered clean sea water without test substance

Test organisms

Test organisms (species):

other aquatic crustacea: Acartia tonsa

Details on test organisms:

TEST ORGANISM
- Name:Acartia tonsa (Dana)
- Source: Originally collected in the North Sea by Danish Institute for Fisheries Research and cultured at DHI Water & Environment (since 1987); Animals were taken from this culture.
- Age at study initiation: Animals were 2-3 weeks of age

Study design

Test type:

not specified

Water media type:

saltwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

Not applicable

Test conditions

Hardness:

Not applicable

Test temperature:

19.5°C +/- 0.5°C

pH:

7.9 - 8.2

Dissolved oxygen:

Oxygen saturation was 96% even at the highest test substance concentration.

Salinity:

32%

Nominal and measured concentrations:

nominal: 0, 100, 200, 500, 1000 and 2000 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 mL glass beakers with 25 mL test solution
- No. of organisms per vessel: 7 adults
- No. of vessels per concentration (replicates): 3 per concentration
- No. of vessels per control (replicates): 5 beakers with 7 animals each

OTHER TEST CONDITIONS
- Photoperiod: light/dark period of 16:8

TEST CONCENTRATIONS
- Test concentrations: 0, 100, 200, 500, 1000 and 2000 mg/L

Reference substance (positive control):

yes

Remarks:

3,5-DCP

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

LC10

Effect conc.:

529 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality

Effect concentrations 2

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

1 271 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality

Effect concentrations 3

Duration:

48 h

Dose descriptor:

other: LC90

Effect conc.:

> 2 000 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

- Mortality of control: < 10%

Results with reference substance (positive control):

- LC50: 1.39 mg/L after 48 hours
- LC10: 0.36 mg/L after 48 hours
- LC90: 2.42 mg/L after 48 hours

Reported statistics and error estimates:

Not applicable

Any other information on results incl. tables

The validation criteria of the test according to the DS/EN ISO 14669, 1999 are considered fulfilled:

- At the end of the test, the O2 -saturation was 96% even at the highest test concentration.

- The mortality of the control group was < 10%.

- The toxicity of the reference chemical (3,5 -DCP) revealed an LC50 of 1.39 mg/L (range: 1.16 - 1.72 mg/L) and was within the specified range of 0.5 - 1.5 mg/L.

Mean LC10, LC50 and LC90 values for treatment with EP-1, potassium salt:

Endpoint	24 hours	48 hours
LC10 [mg/L]	1106	529
LC50 [mg/L]	> 2000	1271
LC90 [mg/L]	> 2000	> 2000

Mean LC10, LC50 and LC90 values for treatment with 3,5 -DCP:

Endpoint	24 hours	48 hours
LC10 [mg/L]	1.05	0.36
LC50 [mg/L]	2.11	1.39
LC90 [mg/L]	3.13	2.42

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In an acute toxicity test in Acartia tonsa, after 48 hours of exposure towards EP-1, potassium salt, an LC50 value of 1271 mg/L was obtained.

Executive summary:

The test substance "EP-1, potassium salt" was tested for the acute toxic effects on the crustacean Acartia tonsa in accordance with the DS/EN ISO 14669 guideline of 1999.

The test was carried out in 50 mL test beakers with 25 mL of test solution in each beaker. The number of dead animals was counted after 24 and 48 hours; total exposure time was 48 hours.

A stock solution of EP-1 potassium salt was prepared by dissolving 400 mg of the test substance in 200 mL seawater, thereby generating a conentration of 2000 mg/L of EP-1 potassium salt. From this, the follwing test concentrations were generated (dilution in seawater): 100, 200, 500, 1000 and 2000 mg/L. Seawater without test substance served as negative control. As reference substance, 3,5 -DCP was used, to test the sensitivity of the test organism.

Chemical analysis revealed that the actual concentration in the stock solution was 1960 mg/L which is equivalent to the nominal concentration. The toxicity of the reference substance was within the expected range.

The results of the study expressed in nominal concentrations can be summarized as follows:

LC10 = 529 mg/L after 48 hours of exposure,

LC50 = 1271 mg/L, after 48 hours of exposure,

LC90 > 2000 mg/L, after 48 hours of exposure.