Sodium 3-[[(dimethylamino)thioxomethyl]thio]propanesulphonate

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:

2016-04-12 - 2016-04-14

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD 202 guideline study under GLP on the registered substance itself without deviations.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

OECD Guideline for Testing of Chemicals No. 202, adopted 13. Apr. 2004: ”Daphnia sp., Acute Immobilisation Test“

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

Council Regulation (EC) No. 440/2008, Method C.2. “Daphnia sp. Acute Immobilisation Test”, adopted 30. May 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Landesamt für Umwelt, Wasserwirtschaft und Gewerbeaufsicht, Kaiser-Friedrich-Straße 7, 55116 Mainz, Germany

Test material

Test material information

Constituent 1

Reference substance name:

Sodium 3-[[(dimethylamino)thioxomethyl]thio]propanesulphonate

EC Number:

242-644-7

EC Name:

Sodium 3-[[(dimethylamino)thioxomethyl]thio]propanesulphonate

Cas Number:

18880-36-9

Molecular formula:

C6H13NO3S3.Na

IUPAC Name:

sodium 3-[(dimethylcarbamothioyl)sulfanyl]propane-1-sulfonate

Test material form:

solid: particulate/powder

Details on test material:

- Name of test material (as cited in study report): sodium 3-[[(dimethylamino)thioxomethyl]thio]propanesulphonate, DPS
- Substance type: pure substance
- Storage condition of test material: The test item was stored in a tightly closed vessel at 15.2- 20.9 °C under dry conditions in the dark.

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0, 10, 18, 32, 56, 100 mg/L

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution containing 100.8 mg/L test item in dilution water was prepared. The solutions of the amount needed were prepared by dilution of this stock solution with dilution water.
- Controls: Blank control were 4 vessels, each containing 20 mL dilution water and 5 Daphnia, Potassium dichromate K2Cr2O7 (CAS No. 7778-50-9) was used as positive control.
- Evidence of undissolved material (e.g. precipitate, surface film, etc): none stated

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna STRAUS
- Strain: Berlin
- Source: Daphnia magna is bred in the LAUS GmbH throughout the year. The animals are kept for the use in toxicity tests. They multiply by parthenogenesis, thus being genetically identical.
- Age at study initiation (mean and range, SD):
- Method of breeding: The husbandry is performed similar to the method described in EN ISO 6341, following SOP 115 002 01 („Zucht und Hälterung von Daphnia magna STRAUS“), Version 12.
Vessels: preserving glasses, nominal volume 2 L
Medium: M4-Medium (recipe of ELENDT)
Food: unicellular green algae (Desmodesmus subspicatus)
Medium renewal: twice a week
- Feeding during test: none

ACCLIMATION
- Acclimation period: none, in-house breeding
- Acclimation conditions (same as test or not): Not the same, but switching from M4-medium (husbandry) to Dilution water (test) has been shown not to cause any detrimental effects for test Daphnia.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

none

Test conditions

Hardness:

2.502 mmol/L; 250 mg CaCO3/L

Test temperature:

18.7 – 21.2 °C

pH:

7.6 (0h) - 7.7 (48h)

Dissolved oxygen:

8.5 - 9.3 mg/L

Nominal and measured concentrations:

0, 10, 18, 32, 56, 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers, nominal volume 50 mL, tall shape
- Material, size, headspace, fill volume: 30 ml headspace
- Aeration: After preparation, the dilution water was aerated.
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Culture medium different from test medium: yes

OTHER TEST CONDITIONS
- Adjustment of pH: After preparation, the dilution water was aerated, the pH measured and if necessary adjusted to 8.4.
- Photoperiod / Light intensity: diffuse lighting

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : After 24 and 48 hours, the immobilised Daphnia were counted. The pH, the concentration of dissolved oxygen and the content of the test item in the test vessels were measured at the beginning and at the end of the test.

TEST CONCENTRATIONS
- Test concentrations: 0, 10, 18, 32, 56, 100 mg/L

Reference substance (positive control):

yes

Remarks:

Potassium dichromate K2Cr2O7 (CAS No. 7778-50-9)

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 3

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 4

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: none noted
- Mortality of control: 0%
- Other adverse effects control: none noted
- Abnormal responses: none noted
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: none noted
- Effect concentrations exceeding solubility of substance in test medium: none

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels: 24h-EC50 of K2Cr2O7 was determined as 1.6 mg/L in a separate GLP study, lying within the demanded range of 0.6 – 1.7 mg/L stated in the guideline
- Limit test: no
- Dose-response test: yes

Reported statistics and error estimates:

95% confidence interval could not be determined as no immobilisation occurred.

Any other information on results incl. tables

Findings

 

Immobility

In the blank control, none of the Daphnia were immobilised (see table below).

 

Table Immobility

Nominal Concentration in mg/L	Immobility 24 hours					Immobility 48 hours
	absolute				in %	absolute				in %
Blank control	0	0	0	0	0	0	0	0	0	0
10	0	0	0	0	0	0	0	0	0	0
18	0	0	0	0	0	0	0	0	0	0
32	0	0	0	0	0	0	0	0	0	0
56	0	0	0	0	0	0	0	0	0	0
100	0	0	0	0	0	0	0	0	0	0

 

pH and O₂

The pH values in the test media and the blank control and the concentration of dissolved oxygen are given in the following tables:

 

Table pH and O₂-values

Nominal Concentration in mg/L	pH		O2-Concentration in mg/L
	0 h	48 h	0 h	48 h
Blank control	7.6	7.7	9.2	8.5
10	7.6	7.7	9.2	8.6
18	7.6	7.7	9.3	8.7
32	7.6	7.7	9.3	8.8
56	7.6	7.7	9.2	8.7
100	7.6	7.7	9.3	8.7

 

Analytical Determinations

The measured concentrations were in the range between 94% and 107 % of the nominal concentration at the start and at the end of the test. Therefore, the determination of the biological results was based on the nominal concentration.

The measured concentrations for treatment and control are given in the following tables:

 

Table Measured Concentrations

Nominal Concentration Test Item	Measured Concentration Test Item t = 0 h	Measured Concentration Test Item t = 48 h
mg/L	mg/L	mg/L
Blank control	< LOQ	< LOQ
10	9.38	10.05
18	17.27	18.82
32	31.03	33.49
56	55.62	59.76
100	96.87	106.52

LOQ (Limit of quantification) = 0.05 mg/L

 

Table Percentage of Nominal Concentrations and Recovery

Nominal Concentration Test Item	% of Nominal concentration t = 0 h	% of Nominal concentration t = 48 h
mg/L	%	%
Blank control	--	--
10	94	101
18	96	105
32	97	105
56	99	107
100	97	107

 

 

Results and Statistics

 

Biological Results Test Item

The biological results are presented in the following table:

 

Table Biological Results Test Item

Parameter	Value	95% confidence interval
24h EC50	> 100 mg/L	not determinable
48h EC50	> 100 mg/L	not determinable
48h NOEC	≥ 100 mg/L	not determinable
48h LOEC	> 100 mg/L	not determinable

 

 

Validity

The 24h-EC50 of K₂Cr₂O₇ should lie between 0.6 and 2.1 mg/L.
The 24h-EC50 of K₂Cr₂O₇ was determined as 1.6 mg/Lin a separate GLP study.

Immobilisation in the controls may not exceed 10 %.
Immobilisation in the controls was 0 %.

The concentration of dissolved oxygen at the end of the test must be at least 3 mg/L. The lowest concentration of dissolved oxygen at the end of the test was 8.5 mg/L.

The pH-value in the test solutions should not vary by more than 1.5 units during the test.
The highest variation was 0.1 units.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The study was conducted under GLP according to OECD guideline 202 and EU method C.2 on the registered substance itself. The method is to be considered scientifically reasonable with no deficiencies in documentation or deviations from the guidelines, the validity criteria were met. Hence, the results can be considered as reliable to assess the toxicity of DPS towards daphnids.
The toxicity against Daphnia magna was tested in a static test design using several concentrations up to 100 mg/L. The concentrations showed no toxicity. None of the animals were immobilised neither in the treatments nor in the control.
Based on the obtained results, sodium 3-[[(dimethylamino)thioxomethyl]thio]propanesulphonate does not need to be classified as hazardous to the aquatic environment according to the Regulation (EC) No. 1272/2008.

Executive summary:

The 48–hr-acute toxicity of sodium 3-[[(dimethylamino)thioxomethyl]thio]propanesulphonate to Daphnia magna STRAUS Berlin was studied under static conditions. Daphnids were exposed to control, positive control Potassium dichromate, and test chemical at nominal concentrations of 0, 10, 18, 32, 56, and 100 mg/L for 48 hr. Immobilization was observed daily. The 48 – hour EC50 was >100 mg/L.  The 48 – hr NOEC based on immobilization was ≥ 100 mg/L. The concentration showed no toxicity. None of the animals were immobilised neither in the treatment nor in the control. 

Based on the results of this study, sodium 3-[[(dimethylamino)thioxomethyl]thio]propanesulphonate would not need to be classified as toxic to daphnids, i.e. hazardous to the aquatic environment in accordance with the classification system of Regulation (EC) No. 1272/2008.

This study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.