3-(2-methoxy-5-methylphenyl)-3-phenylpropanoic acid

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

May 20, 2019 - May 28, 2019

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

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 (control) and 100 mg/L (limit test)
- Sampling method: The test item concentration in the control and the solutions was checked by HPLC/UV at start (t=0h) and at the end of the test (t=48h). All the solutions were analysed taken directly from the starting solutions without daphnids.
- Sample storage conditions before analysis: All the solutions were kept in the refrigerator.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The prepared sample was stirred 24 hours at 20 ± 2°C and at darkness. After this step, the sample was filtered with a cellulose acetate filter (porosity size 0.45 µm).
- Controls: 6 biotic replicates

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: Daphnia magna straus, clone no.5
- Source: Laboratoire de Chimie-Écotoxicologie, FCBA (Institut Technologique Forêt Cellulose Bois, Construction Ameublement), Pôle des Laboratoires Bois, Allée de Boutaut – BP 227, 33028 BORDEAUX Cedex - FRANCE
- Age (mean and range, SD): Daphnids used in this experimentation were previously filtered in order to obtain animals from a size between 560 μm and 800 μm (corresponding to daphnids less than 24 hours old).
- Feeding during test: no

ACCLIMATION
- Acclimation conditions (same as test or not): The daphnids breeding was carried out in closed bottles placed in a climatic chamber free from any toxic vapour and in medium M4.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

250 mg/L as CaCO3

Test temperature:

18 – 22°C, but constant within ±1°C

pH:

6 – 9

Dissolved oxygen:

8.5 – 8.7

Nominal and measured concentrations:

- Nominal concentrations: 0 (control), 100 mg/L.
- Measured concentrations: 0 (control), 95.5 (0h) - 94.7 (48h) mg/L.

Details on test conditions:

TEST SYSTEM
- Test vessel: glass test tubes
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: glass, fill volume 10mL
- Aeration: yes
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 6
- No. of vessels per control (replicates): 6

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: ultrapure water (as described in the guideline).

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: continuous darkness

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): immobilisation (24h, 48h)

RANGE-FINDING STUDY
- Test concentrations: 1st run: 3, 10, 50 mg/L; 2nd run: 50, 100, 328, 1050 mg/L (nominal values; 10 animals/concentration)
- Results used to determine the conditions for the definitive study: 0% immobilisation was observed up to 100 mg/L; 40% immobilisation was observed at 328 mg/L and 10% at 1050 mg/L test item. Therefore, it was concluded that a limit test could be performed.

Reference substance (positive control):

yes

Remarks:

potassium dichromate (May 16, 2019)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: no

Results with reference substance (positive control):

- Results with reference substance valid? yes (result within the accepted interval of 0.6–2.1 mg/L as per ISO 6341, December 2012 and historical data)
- ECx: 24h-EC50 = 1.50 mg/L (1.36 – 1.67)

Table 2. Summary of results.

Observation time	24h	48h
EC50 (mg/l)	> 100 mg/L	> 100 mg/L

Table 3. Daphnids immobilisation results.

Nominal test item concentration ( mg/L)	Number of daphnids exposed at the start	Immobilised daphnids (%)
		at 24h	at 48h
Control	30	0 (0%)	0 (0%)
100	30	0 (0%)	0 (0%)

Table 4. Measured test item concentration during the main test (variation < 20% of the nominal value).

	Concentration (mg test item / L)		Deviation (%)
Nominal test item concentration (mg/L)	Initial time (T0h)	Final time (T48h)
Control	< 0.5	< 0.5	NA
100	95.5	94.7	-0.8

Table 5. Validity criteria.

Validity criterion	Values for OECD 202	Validity criteria for the test
Immobilised daphnids in control	< 10%	Ok (0%)
Dissolved Oxygen concentration	> 3 mg/L	Ok (8.5 mg/L)

Table 6. pH values

Nominal test item concentration (mg/L)	pH
	T0	T48 h
Control	8.5	8.3
100	7.4	7.5

Table 7. Dissolved oxygen.

Nominal test item concentration (mg/L)	O2 (mg/L)
	T0 (Air: 9.4 mg/L)	T48 h (Air: 9.4 mg/L)
Control	8.7	8.6
100	8.7	8.5

Validity criteria fulfilled:

yes

Remarks:

In the control, no daphnids were immobilised (< 10%); the dissolved oxigen concentration at the end of the test was ca. 8.5 mg/L (> 3 mg/L) in the control and test vessels.

Conclusions:

The 48h-EC50 of the test item in Daphnia magna based on immobilisation was found to be > 100 mg/L.

Executive summary:

An acute immobilisation test on Daphnia magna was performed on the test item, according to OECD 202, under GLP conditions. Based on the results obtained in a preliminary test where immobilisation of 20 - 40% was observed at 328 - 1050 mg/L test item, a 48-h exposure limit test at 100 mg/L test item concentration was performed. Blank controls were run in parallel, and a positive control is regularly performed with potassium dichromate. Six replicates were tested for the control and the test item. Test concentrations were analytically determined by means of a validated HPLC-UV method at the beginning and at the end of the test. Since the test item was stable in the test medium (deviation from the measured initial concentration was within ± 20 %), the test results expressed relative to nominal test item concentrations. All validity criteria were met. The 48h-EC50 and the 24h-EC50 of the test item in daphnids were determined to be > 100 mg/L.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

1. SOFTWARE : EPI-SUITE EPA (USA)

2. MODEL: ECOSAR v1.11

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
- SMILES: COC1=C(C=C(C)C=C1)C(CC(O)=O)C1=CC=CC=C1
- Experimental partition coefficient value: Log Kow: 2.440
- Experimental water solubility value: Wat Sol: 14.2 mg/L

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL: The QMRF is available in "Attached justification".

5. APPLICABILITY DOMAIN : The QPRF is available in 'Attached justification'.

6. ADEQUACY OF THE RESULT : The QPRF is available in 'Attached justification'.

Reason / purpose for cross-reference:

other: supporting information

Remarks:

experimental logKow value.

Guideline:

other: REACH Guidance on QSARs R.6

GLP compliance:

no

Specific details on test material used for the study:

SMILES: COC1=C(C=C(C)C=C1)C(CC(O)=O)C1=CC=CC=C1

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

528.7 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: calculated value.

ECOSAR v1.11 predicted that the substance has a 48h-LC50 = 528.7 mg/L in daphnia.

According to the prediction, if the effect level exceeds the water solubility by 10X, typically no effects at saturation (NES) are predicted. The experimental water solubility value of the test item was found to be 14.2 mg/L (20ºC, pH 5).

Validity criteria fulfilled:

not applicable

Conclusions:

The calculated 48h-LC50 of the test item in daphnia is 528.7 mg/L.

Executive summary:

ECOSAR v1.11 calculation of the 48h-LC50 in daphnia was used. According to this method, the 96h-LC50 = 528.7 mg/L of test item in daphnia.

Description of key information

Key study. Method according to OECD 202, GLP study. The 48h-EC50 and the 24h-EC50 of the test item in daphnids were determined to be > 100 mg/L.

Supporting study. ECOSAR v1.11, accepted calculation method. The substance has a predicted 48h-LC50 = 528.7 mg/L in daphnia.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L