Dimethylamine-borane (1:1)

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:

2017-10-27 to 2018-01-29

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)

Version / remarks:

April 13, 2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Sampling: The samples were taken from the biological phase of the study. Collecting, storage and handing over of the samples were the Study Director’s responsibility. The information concerning the samples was provided by the Study Director. Triplicate samples from the freshly prepared test medium of the single test concentration and the control were taken at the start of the test. For the determination of the stability of the test item under the test conditions and of the maintenance of the test item concentration during the test period, triplicate samples from the test medium of the single test concentration and the control were collected at the end of the test (after 48 hours).
- Storage: All samples were stored in a freezer (≤ - 20 °C), protected from light until shipment.
- Shipment: Two replicates of the samples of the single test concentration and the control were shipped from ibacon to the test site of WeylChem InnoTec. Samples were shipped at ambient temperature (+5 to 30 °C) to WeylChem InnoTec.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test medium of the only test concentration of nominal 100 mg test item/L was prepared by dissolving 43.2 mg test item into 432 mL test water by intense stirring for 20 minutes. The test media were prepared just before introduction of the daphnids (= start of the test).
- Controls: In the control, test water was used without addition of the test item.
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: Daphnia magna (Straus), clone 5
- Source: The daphnids introduced in the test were taken from ibacon's in-house laboratory culture.
- Age of parental stock (mean and range, SD): The test organisms were not first brood progeny.
- Feeding during test: no
- Food type: /
- Amount: /
- Frequency: /

ACCLIMATION
- Acclimation period: Was not necessary, since the test was performed in the same medium as the culturing
- Acclimation conditions (same as test or not): same as test
- Type and amount of food: The daphnids in the stock culture were fed at least on all working days with green algae (Desmodesmus subspicatus) freshly grown in the laboratories of ibacon.
- Feeding frequency: All working days

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

2.5 mmol/L (= 250 mg/L) as CaCO3

Test temperature:

20.0 to 20.1 °C at test start;
20.0 °C at test end

pH:

8.3 at test start;
7.8 to 7.9 at test end; and thus the pH-value did not vary by more than 1.5 units

Dissolved oxygen:

9.1 mg/L at test start;
9.0 to 9.1 mg/L at test end

Salinity:

not applicable

Conductivity:

no data

Nominal and measured concentrations:

100 mg test item/L and control

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beakers
- Type (delete if not applicable): The test vessels were covered with a lid to reduce the loss of water due to evaporation and to avoid the entry of dust into the solutions.
- Material, size, headspace, fill volume: Glass beakers of 100 mL volume containing approximately 60 mL of test medium.
- Aeration: no
- Type of flow-through (e.g. peristaltic or proportional diluter): static, no flow-through
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted Water (Elendt "M4"), according to OECD 202
- Culture medium different from test medium: no
- Intervals of water quality measurement: The water temperature, pH-values and dissolved oxygen concentrations were determined at test start and test end in each treatment group.

OTHER TEST CONDITIONS
- Photoperiod: 16 h light : 8 h dark
- Light intensity: The light intensity was 370 to 610 lux (measured once during the test).

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Mortality and Mobility

RANGE-FINDING STUDY
Pre-experiments were performed to determine a suitable concentration range and to establish suitable methods to prepare the test solutions. The pre-experiments were not performed in compliance with the GLP-Regulations and were excluded from the Statement of Compliance in the final report, but the raw data of these tests will be archived under the project number of the present study.
- Test concentrations: not reported
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

yes

Remarks:

For the evaluation of the quality of the Daphnia clone and the consistency of the experimental conditions, the reference item potassium dichromate is tested at least twice a year to demonstrate satisfactory test conditions.

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

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: not observed
- Mortality of control: 0
- Other adverse effects control: no
- Abnormal responses: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: no

Results with reference substance (positive control):

48-h EC50 = 1.07 mg/L

Reported statistics and error estimates:

As no immobilisation or any other abnormal behaviour was observed in any treatment group or control group, a statistical evaluation was not necessary.

- Analytical Results: The quantification of the analyte borane of the test item dimethylamine-borane in the test samples was performed using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). At the start of the test 100 % of the nominal test concentrations were found (average of the only test concentration). After 48 hours test duration, 99 % of the nominal value was determined (average of the only test concentrations). During the test the daphnids were exposed to a mean of 99 % of nominal. 

- Biological Results: The toxic effect of the test item dimethylamine-borane to Daphnia magna was assessed in a static limit test. The 48-hour NOEC was determined to be at least 100 mg test item/L. The NOEC might even be higher than this concentration, but concentrations in excess of nominal 100 mg test item/L or the limit of solubility have not been tested according to the recommendations of the test guidelines. The 48-hour LOEC and the 48-hour EC50 were clearly higher than 100 mg test item/L. These values could not be quantified due to the absence of toxicity of Dimethylamine-borane up to nominal 100 mg test item/L.

The initial concentration and the maintenance of the exposure concentrations during the test were verified in the analytical part. All reported results refer to nominal values since the concentrations of the test item were within ± 20 % of the nominal concentrations during the test.

- Validity Criteria of the Study: Control Immobilisation Rate: Was 0 % and furthermore no daphnid showed signs of disease or stress; thus, the validity criterion was met. Dissolved Oxygen Concentration: Was ≥ 9.0 mg O₂/L in the control and test vessels at the end of the test; thus, validity criterion was met.

Validity criteria fulfilled:

yes

Conclusions:

In an acute toxicity test according to the OECD guideline 202 Daphnia magna was exposed to 100 mg dimethylamine-borane/L. No toxic effect on D. magna was observed.

Executive summary:

The 48-hr-acute toxicity of dimethylamine-borane to Daphnia magna was studied under static conditions.  Daphnids were exposed to control, and test chemical at nominal concentration of 100 mg a.i./L for 48-hr in a limit test.  Mortality, immobilization and sublethal effects were observed daily. The 48- hour EC₅₀ was above 100 mg a.i./L as no effects could be observed. The 48-hr NOEC based on immobilization equals or is above 100 mg a.i./L.

The initial concentration and the maintenance of the exposure concentrations during the test were verified in the analytical part. All reported results refer to nominal values since the concentrations of the test item were within ± 20 % of the nominal concentrations during the test.  

  

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

 

Results Synopsis

 

Test Organism Age (e.g. 1^stinstar): 5 to 21.75 hours old

Test Type (Flowthrough, Static, Static Renewal): Static

 

EC₅₀/LC₅₀> 100 mg a.i./L                           

NOEL ≥ 100 mg a.i./L

                      

Endpoint(s) Effected: Mortality, immobilisation

Description of key information

In an acute toxicity test according to the OECD guideline 202 Daphnia magna was exposed to 100 mg dimethylamine-borane/L. No toxic effect on D. magna was observed.

Additional information

The initial concentration and the maintenance of the exposure concentrations during the test were verified in the analytical part. All reported results refer to nominal values since the concentrations of the test item were within ± 20 % of the nominal concentrations during the test.