4,4'-thiodiethylene hydrogen -2-octadecenylsuccinate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

31st October 2013

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

Daphnia sp., Acute Immobilization Test stipulated in the "Testing Methods for New Chemical Substances" (March 31, 2011, No. 0331-7, Pharmaceutical and Food Safety Bureau, Ministry of Health, Labour• and Welfare; March 29, 2011, No. 5, Manufacturing Industries Bureau, Ministry of
Economy, Trade and Industry; No. 110331009, Environmental Policy Bureau, Ministry of the
Environment, Japan; April 2, 2012 partial revision, No. 0402-1, Pharmaceutical and Food Safety
Bureau, Ministry of Health, Labour and Welfare; March 28, 2012, No. 2, Manufacturing Industries
Bureau, Ministry of Economy, Trade and Industry; No. 120402001, Environmental Policy Bureau, Ministry of the Environment, Japan)

GLP compliance:

yes

Specific details on test material used for the study:

Batch Ref: E00298-234-001

Physicochemical properties
Vapor pressure: 5.12E-39 mmHg (25°C)
Water solubility: Insoluble (visual)
Melting point: 32.5°C
Boiling point: 862°C (measurement pressure 760 mmHg)
Appearance: Brown gelled solid
Stability: Stable at ordinary temperature

Storage condition - The test sample was stored in a dark storage place at room temperature.

Identification and stability of test item under the storage condition - The infrared (IR) spectrum of the test item measured at this laboratory was confirmed to be identical to that provided by the sponsor. The stability of the test item was confumed by comparing the IR spectrum of the test item after the completion of the experiment in a storage condition with that before the start ofthe experiment.

Analytical monitoring:

yes

Details on sampling:

LC-MS/MS analysis (at the start, before and after the renewal, and at the end of exposure)

Vehicle:

yes

Remarks:

water

Details on test solutions:

Required amount of the test sample was melted in a water bath of 40°C setup, was weighed and added into a container for preparation. The test sample added into the preparation container was melted again in a water bath of 40°C setup and daubed onto the bottom of the preparation container with a magnetic stirrer. Required volume of dilution water was added into the container so as to prepare each nominal concentration and stin-ed with a magnetic stirrer in a water bath of 20°C setup for about 48 hours. After that, the stirred solution was settled for approximately 1 hour and the middle layer solution, taken out from the settled solution, was filtered through a membrane filter (GV, 0.22 pm pore size, Millipore) by suction. The filtered solution was stirred in a water bath of 20°C setup for 30 minutes in order to recover dissolved oxygen concentration decreased by suction filtration. The stirred filtrate was used for test solution and divided into each test vessel.

Test organisms (species):

Daphnia magna

Details on test organisms:

Species: Daphnia magna Clone A
Reason for selection of species: Species recommended in the test guideline
Source of supply: The University of Sheffield
(Address: Sheffield S10 2UQ, United Kingdom)
Date of supply: July 9, 1990
Acclimation: Young daphnids produced by parents that were cultured in this laboratoty were used. The parents to obtain young daphnids were bred in the same quality of water (dechlorinated tap water), water temperature (20±1°C) and photoperiod (16-hour light/8-hour dark) as used in the test. The parent animals used for the test were same lot and their age and survival rate were 25-day old and 100%, respectively. Chlorella vulgaris of 0.1-0.2 mgC (Organic carbon content)/day per Daphnia was fed to the parents once a day.
Selection of young daphnids: Less than 24-hour-old daphnids
Allocation to the test groups: Random sampling

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 d

Remarks on exposure duration:

Semi-static regime (renewal at 24 hours after)

Hardness:

30 mg/L

Test temperature:

20±1°C

pH:

7.8 (25.5°C)

Dissolved oxygen:

<1 mg/L

Conductivity:

13mS/m

Nominal and measured concentrations:

Nominal: 0, 9.5, 17, 31, 56, 100 mg/L
Measured soluble fraction Concentration: 0, 0.032, 0.060, 0.044, 0.087, 0.063 mg/L

Details on test conditions:

Type of test: Semi-static regime (renewal at 24 hours after)
Exposure duration: 48 hours
Test concentration: 100, 56, 31, 17 and 9.5 mg/L as nominal concentration (a geometricseries with a factor of 1.8)
The test concentrations and the geometric factor were decided fiom the results of preliminary study. The results of the preliminary study are shown in Additional data.
The results of preliminary study, rejected study, and additional preliminary study are shown in additional data.
Control: Dilution water processing similar to test solution without the test item
Replicate: 4 replicates/test level
Number of organism: 20 daphnids/test level (5 daphnids/test vessel)
Volume of test solution: 400 mutest level (100 mLitest vessel)
Temperature of test solution: 20±1°C
Dissolved oxygen concentration: More than 3 mg/L without aeration
pH adjustment: No adjustment
Irradiation condition: Room light, 16-hour light/8-hour dark
Feeding: No feeding

Key result

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

9.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

24 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Solubility in dilution water (20±1°C): 0.0948 mg/L (measured value in preliminary study)
48-hour EC50: 0.062 mg/L (95% confidence limits: 0.059 - 0.066 mg/L)
-Minimum concentration causing 100% immobility at 48 hours >0.087 mg/L
- Maximum concentration causing no immobility at 48 hours 0.044 mg/L

Reported statistics and error estimates:

95% confidence limits: 0.059 - 0.066 mg/L

The 48-hour EC50 value with the 95% confidence limits was calculated by Moving average method. The 24-hour EC50 value was estimated as ">maximum test concentration" since more than 50% immobility could not be obtained in the range of the exposure concentrations.
The EC50 was estimated by using Computer Program (running on Microsoft software "Excel") developed by the laboratory.

See attached background documents

Validity criteria fulfilled:

yes

Conclusions:

The 24-hour and 48-hour EL50of the test item for Daphnia magna were >100 mg/L and 9.5 mg/L, respectively.

Executive summary:

 

The objective of this study is to determine the 48-hour median effective concentration (EC50) by conducting an acute immobilization study of the Substance inDaphnia magna.

 

Test Substance and dilution water were mixed and stirred for 48 hours. The test solution was prepared by filtering the stirred solution through a membrane filter. Five test concentrations of 100, 56, 31, 17 and 9.5 mg/L as nominal concentration (a geometric series with a factor of 1.8) [0.063, 0.087, 0.044, 0.060 and 0.032 mg/L as measured concentration of the soluble fraction] and a control were tested. Each test concentration was exposed to 4 replicated each containing 5 daphnia in 100mL for 48hours. The test was conducted in a semi-static regime with renewals at 24 hours). The concentration was analysed at the start, before and after the renewal, and at the end of the exposure by LC-MS/MS analysis.

 

During the exposure, the Daphnia were observed for immobility and signs of toxicity. Daphnia were considered immobile if they were not able to swim within 15 seconds after gentle agitation of the test vessels. The 48-hour EC50 value with the 95% confidence limits was calculated by Moving average method. The 24-hour EC50value was estimated as ">maximum test concentration" since more than 50% immobility could not be obtained in the range of the exposure concentrations. The EC50was estimated by using Computer Program (running on Microsoft software "Excel") developed by the laboratory.

 

Immobility in the control during exposure was 0%, which met the criterion for the validity of the test (i.e. not more than 10%).

 

The Substance is considered to be a highly insoluble UVCB and therefore measured soluble fraction is not representative of the Substance as a whole. As a result the loading rates should be used. The report indicates that Substance causes immobility to daphnia. A dose response cannot be identified based on the complexity of responses and possibly confounded by the low solubility of Substance. Immobility to daphnia was observed in nominal WAF preparation of >17 mg/L loading rate across all study date. The nominal loading rate at which no immobilization effect was observed was considered to be 9.5 mg/L. Therefore it is proposed that the no effect nominal loading rate of 9.5 mg/L is used as a conservative surrogate for the EL₅₀.

 

The 24-hour and 48-hour EL50of the test item for Daphnia magna were >100 mg/L and 9.5 mg/L, respectively.

Description of key information

One study was conducted. The 24-hour and 48-hour EL₅₀of the test item forDaphnia magna were >100 mg/L and 9.5 mg/L, respectively.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

9.5 mg/L

Additional information

Acute Daphnia:

 

The objective of this study is to determine the 48-hour median effective concentration (EC50) by conducting an acute immobilization study of the Substance inDaphnia magna.

 

Test Substance and dilution water were mixed and stirred for 48 hours. The test solution was prepared by filtering the stirred solution through a membrane filter. Five test concentrations of 100, 56, 31, 17 and 9.5 mg/L as nominal concentration (a geometric series with a factor of 1.8) [0.063, 0.087, 0.044, 0.060 and 0.032 mg/L as measured concentration of the soluble fraction] and a control were tested. Each test concentration was exposed to 4 replicated each containing 5 daphnia in 100mL for 48hours. The test was conducted in a semi-static regime with renewals at 24 hours). The concentration was analysed at the start, before and after the renewal, and at the end of the exposure by LC-MS/MS analysis.

 

During the exposure, the Daphnia were observed for immobility and signs of toxicity. Daphnia were considered immobile if they were not able to swim within 15 seconds after gentle agitation of the test vessels. The 48-hour EC50 value with the 95% confidence limits was calculated by Moving average method. The 24-hour EC50value was estimated as ">maximum test concentration" since more than 50% immobility could not be obtained in the range of the exposure concentrations. The EC50was estimated by using Computer Program (running on Microsoft software "Excel") developed by the laboratory.

 

Immobility in the control during exposure was 0%, which met the criterion for the validity of the test (i.e. not more than 10%).

 

The Substance is considered to be a highly insoluble UVCB and therefore measured soluble fraction is not representative of the Substance as a whole. As a result the loading rates should be used. The report indicates that Substance causes immobility to daphnia. A dose response cannot be identified based on the complexity of responses and possibly confounded by the low solubility of Substance. Immobility to daphnia was observed in nominal WAF preparation of >17 mg/L loading rate across all study date. The nominal loading rate at which no immobilization effect was observed was considered to be 9.5 mg/L. Therefore it is proposed that the no effect nominal loading rate of 9.5 mg/L is used as a conservative surrogate for the EL₅₀.

 

The 24-hour and 48-hour EL50of the test item for Daphnia magna were >100 mg/L and 9.5 mg/L, respectively.