Trimethylsulfonium bromide

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:

From 20 to 22 Septermber 2022

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Batch No.: 215P13-2
Appearance: White solid
Purity: 99.2%

Analytical monitoring:

yes

Details on sampling:

Because there was not a suitable analytical method for quantifying exposure (e.g. nominal concentrations were below limit of quantification of most sensitive analytical method), confirming nominal test chemical concentrations in a stock solution were used.
During the test, the concentrations of test item in the stock solution of 2500 mg/L were determined at 0 and 24 hours fresh solutions. In addition, in order to demonstrate how the concentration at the sample of the stock solution behaved under test conditions for a renewal period, the stock solution of 2500 mg/L was kept under test conditions for about 24 hours and then the concentration of test item was determined.

Vehicle:

no

Details on test solutions:

2.500 g (actual weight: 2.5013 and 2.5009 g, used for two batches of preparation) test item was weighed and dissolved in 1 L of test water directly. After the test item was dissolved completely, the stock solution of 2500 mg/L was used for dilution of the test solutions.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Method of breeding: The test Daphnia was derived from a same healthy pre-cultured population (i.e. showing no signs of stress such as high mortality, presence of males and ephippia, delay in the production of the first brood, discolored animals, etc.).
- Source: originally obtained from Applied Chemistry Department Pesticide Environmental Evaluation Laboratory of China Agricultural University.
- Age of parental stock (mean and range, SD): The test animals were less than 24 hours old and not the first brood progeny.

ACCLIMATION
- Acclimation period: not specified
- Acclimation conditions (same as test or not): same

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

140 to 250 mg/L (as CaCO3)

Test temperature:

18~22oC

pH:

6.0 to 8.5 pH units

Dissolved oxygen:

not less than 3 mg/L during the test period

Nominal and measured concentrations:

1, 2, 4, 8 and 16 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL glass beakers
- Type (delete if not applicable): open / closed
- Material, size, headspace, fill volume:
- Volume of solution: 100 mL per vessel
- Aeration: Before usage, the water was aerated for more than 24 hours to attain dissolved oxygen saturation.
- Type of flow-through (e.g. peristaltic or proportional diluter):
- Renewal rate of test solution (frequency/flow rate): 24 hours
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates):
- Biomass loading rate:

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hr light: 8 hr dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Biological observation:
Observation intervals: 24 (±1) hours and 48 (±1) hours after exposure.
Method: Each test vessel was checked for immobilized daphnids. In addition to immobility, any abnormal behavior or appearance were recorded. Those animals that are not able to swim within 15 seconds, after gentle agitation of the test vessel are considered to be immobilized (even if they can still move their antennae).

RANGE-FINDING STUDY
- Test concentrations: 1, 2, 10, 50, 100 mg/L
- Results used to determine the conditions for the definitive study: During the period of 48 hours, no immobilization or any toxic signs were observed in the control group and the test group of 1 mg/L, partial immobilization occurred in the test groups of 2 and 10 mg/L, and 100% immobilization occurred in the test groups of 50 and 100 mg/L.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

10.8 mg/L

95% CI:

8.6 - 14.4

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

During the 48-hour exposure period, no immobilization and abnormal behavior or appearance was observed in the control group and the test groups of 1, 2 mg/L, the daphnids exposed to 4, 8 and 16 mg/L showed abnormal behavior such as immobilization and showed increasing immobility effects with increasing concentration.

Results with reference substance (positive control):

EC50-24 h of potassium dichromate to Daphnia magna was 1.17 mg/L, and the 95% confidence limits was 1.04 - 1.33 mg/L. The results met the recommended criterion in OECD Guideline No. 202: EC50-24 h of potassium dichromate is within the range of 0.6 mg/L to 2.1 mg/L.

Validity criteria fulfilled:

yes

Conclusions:

The 48-hour EC50 of the test item to Daphnia magna was determined to be 10.8 mg/L in this study.

Executive summary:

A Daphnia acute immobilization test of test item was conducted with Daphnia magna over a 48-hour exposure period, according to OECD Guideline 202.

The 48-hour EC50 of the test item to Daphnia magna was determined to be 10.8 mg/L in this study.

Description of key information

A Daphnia acute immobilization test of test item was conducted with Daphnia magna over a 48-hour exposure period, according to OECD Guideline 202.

The 48-hour EC50 of the test item to Daphnia magna was determined to be 10.8 mg/L in this study.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

10.8 mg/L