Tetraethylammonium tetrafluoroborate

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:

1 November 2018 - 4 March 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

Adopted April 13, 2004

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

tetraethylammonium tetrafluoroborate

Cas Number:

429-06-1

Molecular formula:

C8H20BF4N

IUPAC Name:

tetraethylammonium tetrafluoroborate

Test material form:

solid: crystalline

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Details on test solutions:

Preparation of test solutions started with the highest concentration of 100 mg/L applying approximately 15 minutes of magnetic stirring to ensure complete dissolution of test item in test medium. Lower test concentrations were prepared by subsequent dilutions of the highest concentration in test medium. All test solutions were clear and colorless at the end of the preparation procedure.
Any residual volumes were discarded.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna (Crustacea, Cladocera) (Straus, 1820), at least third generation, obtained by a cyclical parthenogenesis under specified breeding conditions.
- Source: In-house laboratory culture with a known history.
- Reason for selection: This system has been selected as an internationally accepted invertebrate species.
- Validity of batch: Daphnids originated from a healthy stock, 2nd to 5th brood, showing no signs of stress such as mortality >20% , presence of males, ephippia or discoloured animals and there was no delay in the production of the first brood.
- Characteristics: Daphnia, less than 24 hours old, from parental daphnids of more than two weeks old.

BREEDING
- Start of each batch: Approximately 250 newborn daphnids, i.e. less than 3 days old, were placed into 5 litres of medium in an all-glass culture vessel.
- Maximum age of the cultures: 4 weeks
- Renewal of the cultures: After 7 days of cultivation, half of the medium twice a week.
- Temperature of medium: 18-22°C
- Feeding: Daily, a suspension of fresh water algae.
- Culture medium: M7, as prescribed by Dr. Elendt-Schneider (Elendt, B.-P., 1990: Selenium deficiency in Crustacea. An ultrastructural approach to antennal damage in Daphnia magna Straus. Protoplasma 154, 25-33).

Study design

Test type:

static

Total exposure duration:

48 h

Test conditions

Hardness:

The hardness of test medium expressed as CaCO3: 180 mg/L

Test temperature:

19 - 20°C

pH:

6-9

Dissolved oxygen:

≥3 mg/L

Nominal and measured concentrations:

The measured concentrations at the start of the test were 13, 24, 43, 77 and 126 mg/L at nominal concentrations of 10, 18, 32, 56 and 100 mg/L, respectively.

Details on test conditions:

TEST SYSTEM
- Test Concentrations: 10, 18, 32, 56 and 100 mg/L.
- Test vessel: 60 mL, all-glass.
- Aeration: No aeration of the test solutions was applied
- No. of organisms per vessel: 5 per vessel containing 50 mL of test solution
- No. of daphnids per concentration: 20
- Introduction of daphnids: within 35 minutes after preparation of the test solutions

TEST MEDIUM / WATER PARAMETERS
The following salts (analytical grade) were added to tap water purified by Reverse Osmosis:
CaCl2.2H2O 211.5 mg/L
MgSO4.7H2O 88.8 mg/L
NaHCO3 46.7 mg/L
KCl 4.2 mg/L

OTHER TEST CONDITIONS
- Light: A daily photoperiod of 16 hours

RANGE-FINDING STUDY
- Test concentrations: 20 daphnids per concentration (four replicates, 5 daphnids per vessel) were exposed to a control and a concentration of 100 mg/L.10 daphnids per concentration (in duplicate, 5 per vessel) were exposed to 0.10, 1.0 and 10 mg/L.
- Results: No immobility was observed in the control and at nominal concentrations of 1.0 and 10 mg/L throughout the test. At the end of the test, 10 and 90% immobility was observed at nominal concentrations of 0.1 and 100 mg/L, respectively.
Based on these results, samples taken from nominal concentrations of 10 and 100 mg/L were analysed. The measured concentrations at the start of the test were 15 and 142 mg/L, respectively. During the exposure period, the concentrations remained stable, i.e. were at the level of 97 - 103% of initially measured.

Results and discussion

Effect concentrations

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 126 mg/L

Nominal / measured:

meas. (initial)

Details on results:

No immobility was observed in the control and at any of the test concentrations throughout the exposure period.

Any other information on results incl. tables

In the combined limit/range-finding test, 90% of the daphnids exposed to a measured concentration of 142 mg/L were observed to be immobile at the end of the test. In the final test, no toxicity was observed up to a measured concentration of 126 mg/L.

It should be noted that in both tests, the recoveries of the Quality Control (QC) samples were above the acceptable range of 70-110%. Hence, it might be possible that measured concentrations were slightly over-estimated. In case a correction was made for the high recovery in the QC samples, the measured concentration in both tests would still be at or above the regulatory limit concentration of 100 mg/L. Consequently, it can be stated that there is no toxic effect on the mobility of the daphnids up to the regulatory limit concentration of 100 mg/L. 

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 48h-EC50 for Daphnia magna exposed to Tetraethylammonium tetrafluoroborate exceeded the regulatory limit concentration of 100 mg/L, i.e. exceeded an initially measured concentration of 126 mg/L.

Executive summary:

The objective of the study was to evaluate Tetraethylammonium tetrafluoroborate for its ability to generate acute toxic effects on the mobility of Daphnia magna during an exposure period of 48 hours and, if possible, to determine the EC₅₀ at 24 and 48 hours of exposure.

A final test was performed based on the results of a combined limit/range-finding test. Twenty daphnids per group (5 per replicate, quadruplicate) were exposed to an untreated control and to 10, 18, 32, 56 and 100 mg/L. The total exposure period was 48 hours and samples for analytical confirmation of exposure concentrations were taken at the start and at the end of the test.

Samples taken from all test concentrations and the control were analysed. The measured concentrations at the start of the test were 13, 24, 43, 77 and 126 mg/L at nominal concentrations of 10, 18, 32, 56 and 100 mg/L, respectively. During the exposure period, these concentrations remained stable, i.e. were at the level of 90 - 101% of initially measured at the end of the test. Based on these results, effect parameters were expressed as initially measured concentrations.

No immobility was observed in the control and at any of the test concentrations throughout the exposure period.

The study met the acceptability criteria prescribed by the study plan and was considered valid.

In conclusion, the 48h-EC₅₀ for Daphnia magna exposed to Tetraethylammonium tetrafluoroborate exceeded the regulatory limit concentration of 100 mg/L, i.e. exceeded an initially measured concentration of 126 mg/L.