4-bromo-2,2-diphenylbutyric acid

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:

2016-09-16 to 2016-10-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: Guidance document on aquatic toxicity testing of difficult items and mixtures, OECD series on testing and assessment number 23, December 14, 2000

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

4-bromo-2,2-diphenylbutyric acid

EC Number:

253-648-3

EC Name:

4-bromo-2,2-diphenylbutyric acid

Cas Number:

37742-98-6

Molecular formula:

C16H15BrO2

IUPAC Name:

4-bromo-2,2-diphenylbutanoic acid

Test material form:

solid: particulate/powder

Details on test material:

- Name of test material (as cited in study report): JNJ-1580774-AAA (T000835)
- Physical state: solid powder
- Appearance: slight beige

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: I16BB1136
- Expiration date of the lot/batch: 02 March 2017
- Purity: 99.3% (based on acid titration assay)
- Purity test date: 2016-04-27

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: At room temperature
- Stability under test conditions: not indicated
- Solubility and stability of the test substance in the solvent/vehicle: 0.04 g/L in water

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Sampling method: samples for possible analysis were taken from all test concentrations and the control at t=0 and t=48h. 2.0 mL of volume was taken from the approximate centre of the test vessels. At the end of the exposure period, the replicates were pooled at each concentration before sampling
- Sample storage conditions before analysis: the samples were stored in a freezer. Additionally, reserve samples of 2.0 mL were taken for possible analysis

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Preparation of test solutions started with a loading rate of 100 mg/L applying a three-day period of magnetic stirring to ensure maximum dissolution of the test item in test medium. The resulting aqueous mixture was filtered through a 0.45 µm membrane filter (Whatman; RC55) to remove the undissolved fraction of the test item. The filter was pre-conditioned with a small volume of test solution that was discarded. The obtained Saturated Solution (SS) was used as the highest test concentration. The lower test concentrations were prepared by subsequent dilutions of the SS in test medium.
- Evidence of undissolved material (e.g. precipitate, surface film, etc): final test solutions were clear and colourless

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water-flea
- Source: in-house laboratory culture with a known history
- Age at study initiation (mean and range, SD): <24h (from parental daphnids of more than 2 weeks old)
- Method of breeding: 250 newborn daphnids (i.e. less than 3 days old) are placed into 5 litres of medium in an all-glass culture vessel. Medium is M7. After 7 days of cultivation half of the medium is renewed twice a week.
- Feeding during test: no

ACCLIMATION
- Acclimation period: not relevant

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

180 mg/L as CaCO3

Test temperature:

20°C

pH:

At t= 0h: 7.2 - 8.0
At t= 48h: 7.7-8.1

Dissolved oxygen:

At t= 0h: 9.5-9.9 mg/L
At t= 48h: 8.8-9.0 mg/L

Salinity:

not relevant

Nominal and measured concentrations:

Combined limit/range-finding test
Nominal concentrations (% of the SS): 10, 100% of a SS at 100 mg/L
Measured concentrations (mg/L) at t=0h: 3.00, 30.4 mg/L
Measured concentrations (mg/L) at t=48h: 2.94, 29.9 mg/L

Final test
Nominal concentrations (% of the SS): 0, 10, 18, 32, 56 and 100% of a SS at 100 mg/L
Measured concentrations (mg/L) at t=0h: 0.0051, 2.83, 5.30, 9.14, 16.0, 28.2
Measured concentrations (mg/L) at t=48h: n.d., 2.82, 5.01, 9.00, 15.8, 28.2

All concentrations remained stable during the 48-hour test period (95-100% of initial at the end of the final test).

Details on test conditions:

TEST SYSTEM
- Test vessel: beaker
- Material, size, headspace, fill volume: 100 mL, glass beaker filled with 80mL
- Aeration: not during the test
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

OTHER TEST CONDITIONS
- Photoperiod: 16h light daily

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Immobility, defined as those organisms which are not able to swim within 15 seconds after gentle agitation of the test container. This was monitored after 24 and 48 hours of continuous treatment with the test substance.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8
- Range finding study
- Test concentrations: 1.0, 10 and 100% of a SS prepared at a loading rate of 100 mg/L
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

yes

Remarks:

Potassium Dichromate

Results and discussion

Effect concentrations

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

13 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: CL 95%: 11-15 mg/L

Details on results:

- Immobility of control: none
- Other adverse effects control: no
- Abnormal responses: none

Results with reference substance (positive control):

- Results with reference substance valid? yes (should lie between 0.3 and 1.0 mg/L)
- EC50/LC50: 48h-EC50 = 0.39 mg/L the sensitivity of the daphnia was within the range determined with the historical data collected at WIL Research Europe.

Reported statistics and error estimates:

The 24 and 48h-EC50 value was calculated from the weibits of the percentages of affected daphnids and the logarithms of the corresponding test item concentrations (initially measured) using the maximum likelihood estimation method.
ToxRat Professional v 3.2.1 (ToxRat Solutions® GmbH, Germany) was used to perform the analyses.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The acute toxicity of T000835 to Daphnia magna was determined in a 48-hour static test according to the OECD guideline 202.
The 48h-EC50 was 13 mg/L based on measured concentrations (95% confidence interval between 11 and 15 mg/L. The results of the test can be considered reliable without restriction.