4,4'-thiodiethylene hydrogen -2-octadecenylsuccinate

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

31st October 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

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:

at the start of exposure, 24 and 48 hours after the start of exposure, and the end of exposure

Vehicle:

yes

Details on test solutions:

Required amount of test sample melted in water bath set to 40°C was taken out and added to a preparation container. Then the test sample was remelted in water bath set to 40°C and daubed onto bottom of the preparation container with a magnetic stirrer. Medium were added in the preparation container to prepare 100 mg/L (nominal), and they were stirred with a magnetic stirrer for 48 hours. After cease of stirring, the suspension was filtered with a membrane filter (GV, 0.22 pm pore size, Millipore) by suction. The filtrate was used as test solution and divided into each test vessel.

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

Species: Pseudokirchneriella subcapitata
Reason for selection of species: Species recommended in the test guidelines
Source: American Type Culture Collection
Strain number: ATCC 22662
Supplied date: June 30, 1995
Subculture: Passage cultured under sterile conditions in this laboratory
Confirmation of reproducibility of test system
Algae growth inhibition test with a reference substance was periodically conducted.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Hardness:

Not stated

Test temperature:

2.5-22.8°C

pH:

7.7-7.9

Dissolved oxygen:

Not stated

Salinity:

Not stated

Conductivity:

Not stated

Nominal and measured concentrations:

Nominal concentration = 100 mg/L
Measured concentration = 0.054 mg/L

Details on test conditions:

Type of test: Incubation with rotary shaking (approximately 100 rpm)
Duration: 72 hours
Test concentration: Limit test at around the solubility in medium (0.151 mg/L: Measured value in preliminary study)
The test concentration was decided based on the results of preliminary study.
The results of the preliminary study are shown in Additional data.
Control: The medium without the test item, which was treated in the same manner as test solution.
Replicate: 6 replicates / test level
(Three replicates for analytical chemistry of the test item were set for 24 and 48 hours additionally.)
Volume of test solution
600 mL / test level (100 mL / test vessel)
(Three test vessels for analytical chemistry of the test item were set for 24 and 48 hours additionally.)
Initial cell concentration
The algae were counted in pre-culture incubated under the same conditions as the test for 3 days (from September 14 to September 17, 2013) as inoculums, and were added to test vessels to bring the initial cell concentration of 0.75x104 cells/mL.
Operation: All operations were carried out under sterile conditions.
Temperature: 21-24°C ( not varied more than ±2°C)
Light intensity: Nominal 90µEm-2s-1+20% (within ±15% from the average light intensity). Continuous illumination provided by fluorescent lights with wavelength range of 400-700 nm.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate used, checked by periodically by lab.

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.053 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

growth rate

Reported statistics and error estimates:

F test and Aspin-welch t-test

Values were rounded in accordance with MS Z 8401 lute B, 1999.
(JIS ; Japanese Industrial Standards)

See attached background documents

Validity criteria fulfilled:

yes

Conclusions:

EC50 (ErC50) >100 mg/L
NOEC (Growth rate 0-3d) >100 mg/L

Executive summary:

The objective of this study was to determine the toxicity of the test substance to the freshwater green alga (Pseudokirchneriella subcapitata) during a 72-hour exposure period.

 

The green alga (Pseudokirchneriella subcapitata) was exposed to five nominal WAF loading rates and a negative control (culture medium) under static conditions for 72 hours. Six replicate test chambers in the control group and treatment group were maintained. Due to the low solubility of the test substance, test solutions were prepared as water accommodated fractions (WAFs) and test concentrations are based upon the loading rate for each test solution. This study was conducted as a limit test in order to estimate the effect on the test organisms at around the solubility of the test item in medium. Test sample and medium were mixed to prepare 100 mg/L (nominal), and they were stirred for 48 hours. After settling, suspension was filtered with a membrane filter to prepare the test solution. The concentration of Test substance in test solution was also analysed at the start of exposure, 24 and 48 hours after the start of exposure, and the end of exposure by LC-MS/MS analysis.

 

The toxicity of Substance to green alga (Pseudokirchneriella subcapitata) was determined by evaluating changes in cell density over a 72-hour exposure period. Cell densities were used to calculate growth rates at 24-hour interval of exposure and yield at 72 hours of exposure.

 

This test achieved all validity criteria specified in the study protocol which was based on the OECD 201 guideline.

 

The algal growth of the exposure level was same as control level. The results of the cell observation showed that cells in control were normal, and cells in the exposure level were the same as control.

 

The measured concentration of the test item with 100 mg/L (nominal) was 0.054 mg/L. As a result of the statistical analysis of the growth rate, a significant difference was not found. By the results in statistical analysis and cell observation, the ErC50 and NOEC of the Test Substance based on growth rate was estimated at > 100 mg/L (nominal) (Measured >0.054 mg/L).

Description of key information

The ErC50 and NOEC of the Test Substance based on growth rate was estimated at > 100 mg/L (nominal)

Key value for chemical safety assessment

EC50 for freshwater algae:

100 mg/L

EC10 or NOEC for freshwater algae:

100 mg/L

Additional information

Algae inhibition Study:

The objective of this study was to determine the toxicity of the test substance to the freshwater green alga (Pseudokirchneriella subcapitata) during a 72-hour exposure period.

 

The green alga (Pseudokirchneriella subcapitata) was exposed to five nominal WAF loading rates and a negative control (culture medium) under static conditions for 72 hours. Six replicate test chambers in the control group and treatment group were maintained. Due to the low solubility of the test substance, test solutions were prepared as water accommodated fractions (WAFs) and test concentrations are based upon the loading rate for each test solution. This study was conducted as a limit test in order to estimate the effect on the test organisms at around the solubility of the test item in medium. Test sample and medium were mixed to prepare 100 mg/L (nominal), and they were stirred for 48 hours. After settling, suspension was filtered with a membrane filter to prepare the test solution. The concentration of Test substance in test solution was also analysed at the start of exposure, 24 and 48 hours after the start of exposure, and the end of exposure by LC-MS/MS analysis.

 

The toxicity of Substance to green alga (Pseudokirchneriella subcapitata) was determined by evaluating changes in cell density over a 72-hour exposure period. Cell densities were used to calculate growth rates at 24-hour interval of exposure and yield at 72 hours of exposure.

 

This test achieved all validity criteria specified in the study protocol which was based on the OECD 201 guideline.

 

The algal growth of the exposure level was same as control level. The results of the cell observation showed that cells in control were normal, and cells in the exposure level were the same as control.

 

The measured concentration of the test item with 100 mg/L (nominal) was 0.054 mg/L. As a result of the statistical analysis of the growth rate, a significant difference was not found. By the results in statistical analysis and cell observation, the ErC50 and NOEC of the Test Substance based on growth rate was estimated at > 100 mg/L (nominal) (Measured >0.054 mg/L).