4-(5-Propyl-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:

Jul 28 - Nov 13, 2021

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:

2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

Council Regulation (EC) No. 440/2008 laying down test methods pursuant to Regulation (EC) No. 1907/2006 of the European Parliament and the council on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH).

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Preparation of the Test Item:
A stock preparation with a test item concentration of 100 mg/L was freshly prepared. For that purpose, the test item was weighed in a calibrated flask and vehicle was added. The preparation was stirred with a magnetic stirrer for 24 hours. Then the formulation was passed through a filter membrane (pore size: 0.2 µm). The filtrate was used for the study. The pH was not adjusted.

Analytical monitoring:

yes

Details on sampling:

Analysis of the test item concentration directly after preparation and at the end of the exposure period was performed in an analytical laboratory at the test facility.
One replicate was given to the analytical laboratory for analysis. The second replicate was deep-frozen (≤ -20°C) as backup. The samples were measured either undiluted (1.0 mg/L) or diluted (2.2 mg/L to 23.4 mg/L). Finally, the concentration of the test item in each sample was quantified using a calibration curve. Blank and control samples were included to identify interfering peaks. Test media samples were measured by a single measurement.

Vehicle:

yes

Details on test solutions:

Macro nutrients (mg/L)
CaCI2 •2H20 293.80
MgSO4•7H20 123.30
NaHCO3 64.80
KCI 5.80
Na2SiO3•9H20 10.00
NaNO3 0.27
KH2PO4 0.14
K2HPO4 0.18

Trace elements (mg/L)
B 0.5000
Fe 0.2000
Mn 0.1000
Li, Rb and Sr 0.0500
Mo 0.0250
Br 0.0125
Cu and Zn 0.0063
Co and I 0.0025
Se 0.0010
V 0.0003

Macro nutrients (mg/L)
Na2EDTA • 2H20 2.50

Vitamins (µg/L):
Thiamine 75.00
B12 1.00
Biotin 0.75

- pH: 7.97
- O2: 8.36 mg/L
- Conductivity: 724 µS/cm
- Total hardness: 248 mg CaCO3/L

Preparation of the Test Item:
A stock preparation with a test item concentration of 100 mg/L was freshly prepared. For that purpose, the test item was weighed in a calibrated flask and vehicle was added. The preparation was stirred with a magnetic stirrer for 24 hours. Then the formulation was passed through a filter membrane (pore size: 0.2 µm). The filtrate was used for the study. The pH was not adjusted.

Test organisms (species):

Daphnia magna

Details on test organisms:

Species: Daphnia magna Straus
Culture conditions: The clone is bred in the laboratories .
Parental daphnids are used for reproduction until they are about 6 weeks old. Thereafter, they are replaced by neonates.
Daphnids are kept individually in 100 mL glass vessels containing approximately 60 mL reconstituted water (ELENDT M4 medium) at a water temperature of 20 ± 2°C and a 16 hour light and 8 hour
dark regime to ensure similar conditions as in the experiment. Offspring are removed from the vessels at least twice per week.
Feeding: The parental daphnids are fed ad libitum with unicellular green algae Desmodesmus subspicatus three times per week.
Age: Offspring less than 24 hours old were used for the study.
Acclimation period: same as test

Feeding during test: None

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

240 mg/L as CaCO3

Test temperature:

20.9 to 21.5°C

pH:

7.84 to 7.99

Dissolved oxygen:

8.23 - 8.49 mg/L

Conductivity:

564 µS/cm

Nominal and measured concentrations:

Nominal 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass test tubes
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: 20 mL glass test tubes containing 20 mL medium
- Aeration: no
- 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 medium according OECD 202)
- Total organic carbon: no data
- Particulate matter: no data
- Metals: no data
- Pesticides: no data
- Chlorine: no data
- Alkalinity: no data
- Ca/mg ratio: no data
- Conductivity: 564 µS/cm
- Salinity: no data
- Culture medium different from test medium: no
- Intervals of water quality measurement: at start and end of exposure

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16h light / 8h dark
- Light intensity: The mean light intensities were 665 Lux and 672 Lux prior to and at the end of the exposure period

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Immobilisation (daily)

VEHICLE CONTROL PERFORMED: no

RANGE-FINDING STUDY
- Test concentrations: 100 mg/L
- Results used to determine the conditions for the definitive study: no immobilisation observed at 100 mg/L

Reference substance (positive control):

no

Remarks:

No positive control used in this study. The accuracy and reliability of the test method is demonstrated periodically as recommended by guidelines with potassium dichromate.

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

5.86 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

4.89 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The recovery rates of the test material directly after preparation were between 47.6% to 48.9% and between 44.6 and 47.5% at the end of the exposure period. No test item was measured in the control medium.
As the test item concentrations could be maintained >80% of the initial measured concentrations after 48 hours (92.8 to 97.4%), the EC values were calculated based on the initial measured concentrations.


Under the conditions of the present study, the test item showed a 48h EC50 of 4.89 mg/L for the immobilization of Daphnia magna.

Results with reference substance (positive control):

the positive control substance, Art. 104864 (Potassium dichromate), showed a 24h EC50 value of 0.81 mg/L which is within the range of the published data of 0.6 to 1.7 mg/L (Council Regulation (EC) No. 440/2008) and 0.6 to 2.1 mg/L (OECD Guideline No. 202).



Objective:
The objective of this study was to determine the effect of the positive control substance
Art. 104864 (Potassium dichromate) on the immobilization of Daphnia magna in order to check the sensitivity of the test system as recommended by guidelines (Council Regulation (EC) No. 440/2008 and OECD Guideline No. 202).

Study design:
Juvenile daphnids were exposed to different concentrations of the test item (0, 0.31, 0.46, 0.69, 1.02 and 1.52 mg/L) in an open static system. 20 daphnids, divided into four replicates, each with five animals were used per concentration and control. The daphnids were observed for immobilization after 24 and 48 hours of exposure.

Results:
No effect on the mobility of the daphnia was observed at the two lowest concentrations of
0.31 mg/L and 0.46 mg/L. A concentration dependent immobilization was observed at concentrations of 0.69 to 1.52 mg/L.


EC50 values with 95% confidence intervals:
24h EC50 1.13 mg/L (0.98 – 1.34 mg/L)
48h EC50 0.74 mg/L (0.66 – 0.82 mg/L)

Conclusion:
Under the conditions of the present study, the test item Potassium dichromate showed a 24h EC50 value of 1.13 mg/L which is within the range of the published data of 0.6 to 1.7 mg/L (Council Regulation (EC) No. 440/2008) and 0.6 to 2.1 mg/L (OECD Guideline No. 202).

Therefore, this study confirms the sensitivity and reliability of the test system used in the test facility.

Nominal Test Item Concentration [mg/L]	Number of daphnids immobilized / exposed		% of daphnids immobilized
	24 hours	48 hours	24 hours	48 hours
0.0	0/20	0/20	0%	0%
1.0	0/20	0/20	0%	0%
2.2	0/20	0/20	0%	0%
4.8	0/20	0/20	0%	0%
10.6	3/20	13/20	15%	65%
23.4	20/20	20/20	100%	100%

Test Duration	EC50	95% Confidence Interval
24h	5.86 mg/L	n.d.*
48h	4.89 mg/L	n.d.*

*n.d. = could not be determined due to mathematical reasons or inappropriate data by ToxRat Professional

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the present study, the test item showed a 48h EC50of 4.89 mg/L for the immobilization of Daphnia magna.

Description of key information

Under the conditions of the study performed, the test item showed a 48h EC50 of 4.89 mg/L for the immobilization of Daphnia magna.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

> 4.89 mg/L