4'-Ethyl-2,3-difluorbiphenyl-4-boronic acid

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:

06 Aug - 11 Oct 2018

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)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

One sample from the freshly prepared stock solution filtrate (filtrate of 100 mg test item/L) and duplicate samples from the freshly prepared test media of all test concentrations 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 concentrations during the test period, duplicate samples from the test media of all test concentrations and the control were collected at the end of the test (after 48 hours) by pouring together the contents of the test beakers of each treatment.
All samples were diluted by a factor of 2 with acetonitrile.
Additional samples of the control and the dilution solvent were taken at each sampling without any sample treatment.
All samples were stored in a freezer (≤ - 20 °C), protected from light, until analysis was performed.

Vehicle:

no

Details on test solutions:

Reconstituted Water (Elendt "M4"): Analytical grade salts and additives were added at the following nominal concentrations in deionised water (conductivity < 5 μScm-1):
-------------------------------------------------------------------------------------------------------------------------
Main Compounds Trace Elements Vitamins
-------------------------------------------------------------------------------------------------------------------------
CaCl2·2 H2O 293.80 mg/L H3BO3 2860 μg/L Thiamin HCl 75.0 μg/L
MgSO4·7 H2O 123.30 mg/L MnCl2·4 H2O 361 μg/L Cyanocobalamin (B12) 1.0 μg/L
KCl 5.80 mg/L LiCl 306 μg/L Biotin (B6) 0.75 μg/L
NaHCO3 64.80 mg/L RbCl 71 μg/L
Na2SiO3·9 H2O 10.00 mg/L SrCl2·6 H2O 152 μg/L
NaNO3 0.27 mg/L NaBr 16 μg/L
KH2PO4 0.14 mg/L Na2MoO4·2 H2O 63 μg/L
K2HPO4 0.18 mg/L CuCl2·2 H2O 17 μg/L
ZnCl2 13 μg/L
CoCl2·6 H2O 10 μg/L
KI 3.3 μg/L
Na2SeO3 2.2 μg/L
NH4VO3 0.6 μg/L
Na2EDTA·2 H2O 2.5 mg/L
FeSO4·7 H2O 1.0 mg/L
-------------------------------------------------------------------------------------------------------------------------
Water Hardness: 2.5 mmol/L (= 250 mg/L) as CaCO3 Alkalinity: 0.9 mmol/L

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain/clone: Daphnia magna
- Justification for species other than prescribed by test guideline: accepted by Guideline
- Source: in house
- Age of parental stock (mean and range, SD): 0.75 - 18 hours
- Feeding during test: no
- Food type: -
- Amount: -
- Frequency: -

ACCLIMATION
- Acclimation period: no
- Acclimation conditions (same as test or not): -
- Type and amount of food: -
- Feeding frequency: -
- Health during acclimation (any mortality observed): -

QUARANTINE (wild caught)
- Duration: -
- Health/mortality: -

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES:

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

250 mg/L

Test temperature:

20.6 - 20.9 °C

pH:

7.7 - 8.0

Dissolved oxygen:

8.6 to 9.2 mg/L

Salinity:

-

Conductivity:

-

Nominal and measured concentrations:

nominal: 1 0.5 0.25 0.125 0.063 mg/L
analytical: 0.117 0.0615 0.033 0.0204 0.010 mg/L

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.045 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Validity criteria fulfilled:

yes

Conclusions:

The toxic effect of the test item to Daphnia magna was assessed in a static concentration-response test. The 48-hour EC50 value was calculated to be 0.045 mg test item/L based on mean measured concentrations.
The initial concentrations and the maintenance of the exposure concentrations during the test were verified in the analytical part. All reported results refer to mean measured concentrations since the concentrations of the test item were not within ± 20% of the nominal concentrations due to filtration of the stock solution.

Description of key information

OECD 202:

EC50 (48 h) = 0.045 mg/l (mean measured concentration)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.045 mg/L