4-(5-Ethyl-tetrahydropyran-2-yl)-phenol

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:

22 Sep 2017

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)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

At the start of the exposure and at the renewal (24 and 48 h), samples of the freshly prepared test item concentrations were taken and analyzed.
At renewal and at the end of the exposure (24 and 48 h), sampled of the 24 h old media were taken directly fron the test vessels and analyzed.

Vehicle:

yes

Remarks:

dilution water

Details on test solutions:

Stock solution:
A stock solution (100 mg/L of the test item were weighed out) was freshly prepared with dilution water prior to the start of the exposure (0 h) and prior to the renewal of the test solutions (24 h). The stock solution was mixed thoroughly by manual agitation.

Test concentrations:
5 test item concentrations ina geometirc series with a separation factor of 2, prepared by dilution of the stock solution of 100 mg/L with dilution water were tested as follows: 6.25, 12.5, 25.0, 50.0 and 100 mg/L.

Control:
Dilution water without test item incubated under the same semi-static conditions as the test group.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna STRAUS (Clone 5)
- Source: Institut für Wasser-, Boden und Lufthygiene (WaBoLu), Berlin, Germany
- Age: < 24 h

FEEDING DURING TEST
- Food type: 5 x per week ad libitum with a mix of unicellular green algae

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

0 h: 170 mg CaCO3/L
24 h: 178 mg CaCO3/L

Test temperature:

20.8 - 20.9 °C

pH:

0 h: 8.61
24 h: 8.24

Dissolved oxygen:

0 h: 8.76 mg/L
24 h: 8.90 mg/L

Conductivity:

0 h: 448 µS/cm
24 h: 462 µS/cm

Details on test conditions:

Test vessels:
Glass beakers, 50 mL capacity, loosely covered with watch glasses
Test volume:
20 mL
Number of daphnids and replicates:
20 daphnids, divided into 4 replicates, each with 5 daphnids were used for each concentration level and control.
Application:
20 g test solution per replicate was weighed out into each test vessel. This corresponds to 20 mL per test vessel. The daphnids were inserted with a samll amount of dilution water (start of the exposure) or test solution (water renewal) by pipette.
Renewal of the test solutions:
The test solutions were renewed after 24 h. For this purpose, a second set of test vessels was filled with the freshly prepared test solutions and the daphnids were transferred by pipette.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

10.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

16.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Table 1: Immobilization rates after 24 and 48 h

Nominal test item conc. [mg/L]	Immobilization [%]
	24 h					48 h
	Replicates					Replicates
	1	2	3	4	MV	1	2	3	4	MV
100	100	100	100	100	100	100 % mortality after 24 h
50.0	100	100	100	100	100	100 % mortality after 24 h
25.0	80	100	100	100	95	100	100	100	100	100
12.5	20	0	20	20	15	60	80	80	100	80
6.25	0	0	0	0	0	0	0	0	0	0
control	0	0	0	0	0	0	0	0	0	0

Validity criteria fulfilled:

yes

Conclusions:

Based on the nominal concentrations of the test item, the 48 h EC50 for Daphnia magna was 10.8 mg/L (95% confidence limits: 6.48 - 12.4 mg/L).

Executive summary:

In the acute immobilization test with Daphnia magna (STRAUS), the effects of the test item were determined according to OECD 202 (2004).

The study was conducted under semi-static conditions over a period of 48 hours with 5 concentrations of the test item in the range of 6.25 to 100 mg/L, prepared in a geometric series with a separation factor of 2.

All tested concentration levels were visually clear throughout the exposure. Twenty daphnids (divided into 4 replicates with 5 daphnids each) were exposed to each concentration level and the control.

The concentrations of the test item were analytically verified via HPLC-DAD in fresh media of all concentration levels and in the control at the start of the exposure and at renewal (0 and 24 hours) and in 24-hours old media at renewal and at the end of the test (24 and 48 hours).

 

The measured concentrations of the test item in fresh media at the start of the exposure and at renewal (0 and 24 hours) were in the range of 90 to 100% of the nominal values, and 88 to 100% in old media at renewal and at the end of the test (24 and 48 hours).

The measured test item concentrations were all within ± 20% of the nominal concentrations. This indicates that the test item concentrations were successfully maintained for the duration of the test. Therefore, all effect concentrations are based on the nominal concentrations of the test item.

The validity criteria of the test guidelines were fulfilled.

 

Based on the nominal concentrations of the test item, the 48 hour-EC50 for Daphnia magna was 10.8 mg/L (95% confidence limits: 6.48 - 12.4 mg/L).

 

Description of key information

OECD 202: 48 -h EC50 = 10.8 mg/L (nominal)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

10.8 mg/L

Additional information

In the acute immobilization test with Daphnia magna (STRAUS), the effects of the test item were determined according to OECD 202 (2004).

The study was conducted under semi-static conditions over a period of 48 hours with 5 concentrations of the test item in the range of 6.25 to 100 mg/L, prepared in a geometric series with a separation factor of 2.

All tested concentration levels were visually clear throughout the exposure. Twenty daphnids (divided into 4 replicates with 5 daphnids each) were exposed to each concentration level and the control.

The concentrations of the test item were analytically verified via HPLC-DAD in fresh media of all concentration levels and in the control at the start of the exposure and at renewal (0 and 24 hours) and in 24-hours old media at renewal and at the end of the test (24 and 48 hours).

 

The measured concentrations of the test item in fresh media at the start of the exposure and at renewal (0 and 24 hours) were in the range of 90 to 100% of the nominal values, and 88 to 100% in old media at renewal and at the end of the test (24 and 48 hours).

The measured test item concentrations were all within ± 20% of the nominal concentrations. This indicates that the test item concentrations were successfully maintained for the duration of the test. Therefore, all effect concentrations are based on the nominal concentrations of the test item.

The validity criteria of the test guidelines were fulfilled.

 

Based on the nominal concentrations of the test item, the 48 hour-EC50 for Daphnia magna was 10.8 mg/L (95% confidence limits: 6.48 - 12.4 mg/L).