(R)-2-(2,4-Difluorphenyl)-1,1-difluor-3-(tetrazol-1-yl)-1-{5-[4-(2,2,2-trifluorethoxy)-phenyl]-2-pyridyl}-2-propanol-(R,R)-tartrate

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:

01 May 2020 - 21 August 2020

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:

13 April 2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

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. An additional intermediate sampling point after 24h was also performed.
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 date without any sample treatment.
All samples were stored in a freezer (≤ - 20 °C), protected from light, until analysis was performed. Afterwards the samples were again stored deep frozen (≤ -20 °C) and will be kept stored up to the date of the final report.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: a supersaturated stock solution of nominal 100 mg test item/L was prepared by suspending 89.9 mg test item in 899 mL test water. The stock suspension was stirred for 48.3 hours at room temperature in the dark to dissolve as much test item as possible. Then, non-dissolved fractions of the test item were separated from the test medium by membrane filtration (0.45 µm cellulose acetate filter). The filtrate with dissolved test item was used to prepare the desired dilutions of 1:50, 1:110, 1:242, 1:532, 1:1171, 1:2577, 1:5669.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain/clone: clone 5
- Age at study initiation: 1.25 - 17.50 h
- Method of breeding: Parental daphnids in Elendt M4 medium
- Source: in-house culture of Ibacon

ACCLIMATION
- Acclimation period: none, already cultured in test medium

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

20.0 - 20.6

pH:

8.0

Dissolved oxygen:

8.9 - 8.7 mg/L

Nominal and measured concentrations:

Nominal: 1:50, 1:110, 1:242, 1:532, 1:1171, 1:2577 and 1:5660 dolutions of 100 mg/L filtrated solution.
Measured (geometric mean): 1097, 508, 225, 104, 42.5, 15.8, 7.17 µg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 ml glass beaker
- Type: closed
- Material, size, headspace, fill volume:
- Volume of solution: 60 ml
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16:8 (h, light:dark)
- Light intensity: 300-570 lux

EFFECT PARAMETERS MEASURED: immobilisation after 24 and 48h

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

684 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

225 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

474 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Results with reference substance (positive control):

- Results with reference substance valid? yes. The sensitivity of the daphnids was consistent with the level proposed by the OECD 202 guideline (EC50 between 0.6 and 2.1 mg potassium dichromate/L)

Table 1: Effect concentrations

Endpoint	24 hours	48 hours
	[µg test item/L]
EC50	< 1097	684
95 % CI	n.d.	585 - 800
EC20	< 1097	537
95 % CI	n.d.	449 - 643
EC10	n.d.	474
95 % CI	n.d.	384 - 585
NOEC	508	225
LOEC	1097	508

Table 2: Sumary of immobilised daphnids (%)

Geometric Mean Measured Concentration [µg test item/L]	% of immobilized daphnids after
	24 hours	48 hours
Control	0	0
7.17	0	0
15.8	0	0
42.5	0	0
104	0	0
225	0	0
508	0	15
1097	10	95

Validity criteria fulfilled:

yes

Conclusions:

The 48-hour NOEC of (R)-3-Amino-2-(2,4-difluorophenyl)-1,1-difluoro-1-(5-(4-(2,2,2-trifluoroethoxy)phenyl)pyridin-2-yl)propan-2-ol L-tartrate was determined to be 225 µg test item/L. The 48-hour LOEC was determined to be 508 µg test item/L and the 48-hour EC50 value was calculated to be 684 µg test item/L.

Executive summary:

The 48–hr-acute toxicity of (R)-3-Amino-2-(2,4-difluorophenyl)-1,1-difluoro-1-(5-(4-(2,2,2-trifluoroethoxy)phenyl)pyridin-2-yl)propan-2-ol L-tartrate to Daphnia magna Straus was studied under static conditions. Test species were exposed to control and test chemical at measured concentrations of 0, 7.17, 15.8, 42.5, 104, 225, 508, 1097 µg test item/L for 48 hr.  Immobilisation was observed at 24 and 48 h.  The 48–hour EC₅₀was 684 µg/L.  The 48–hr NOEC based on immobilization was 225 µg test item/L. 

 

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

 

Results Synopsis

 

Test Organism Age: 1.75 - 17.50h

Test Type: static

 

NOEC:  225 µg test item/L                       

EC₅₀:  684 µg test item/L                       95% C.I.:  585 to 800 µg test item/L

Endpoint Effected:  immobilisation

Description of key information

In a single key study on the 48–hr-acute toxicity of (R)-3-Amino-2-(2,4-difluorophenyl)-1,1-difluoro-1-(5-(4-(2,2,2-trifluoroethoxy)phenyl)pyridin-2-yl)propan-2-ol L-tartrate to Daphnia magna Straus was studied according to OECD guideline 202. The 48–hour EC₅₀was 684 µg/L. The study was conducted under static conditions and fulfilled all criteria for a valid test.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

684 µg/L

Additional information

Daphnia magna were exposed to control and test chemical at measured concentration of 0, 7.17, 15.8, 42.5, 104, 225, 508, 1097 µg test item/L for 48 hr.  Immobilisation was observed at 24 and 48 h.  The 48–hour EC₅₀was 684 µg/L.  The 48–hr NOEC based on immobilization was 225 µg test item/L.