Ethyl 3-phenyloxirane-2-carboxylate

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:

18 April 2000 - 20 April 2000

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Analytical concentrations include parent and metabolites.

Justification for type of information:

Information is used for read across.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

1984

Deviations:

yes

Remarks:

Anylysed concentrations included parent substance and metabolites.

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Test concentrations were verified by DOC analysis. Samples were taken from the control and test concentrations of 32, 58 and 100 mg/L at t=0.
Test concentrations were only analytically verified at the beginning of the test. Therefore, the stability of the test item under test conditions was not known. However, analytical results of an acute fish study with this test substance indicated stability over 24 hours renewal periods. It can be assumed that the test substance is stable and therefore this deviation had no impact on the quality and the integrity of the study.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test item was added to dilution water, followed by 24 h stirring on a magnetic stirrer. A nominal stock solution of 100 mg/L was prepared with dilution water. The test item was clearly dissolved in all tested concentration levels throughout exposure.
Dilution water used was according to EC C.2.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain: STRAUS (Clone 5)
- Source: Institut fur Wasser-, Boden- und Lufthygiene des Bundesgesundheitsamtes, Corrensplats, 14195 Berlin, FRG
- Age at study initiation: Gravid adults were isolated 24 hours prior to initiation of the test. Young daphnids (2-24 h old) produced overnight were used for testing.
- Acclimation: daphnids have been acclimatized to the dilution water 2 h before test started under test conditions.
- Culture: in 2-3 L glass vessels with approximately 1.8 L culture medium, by 21 °C, in an incubator, 16 h illumination (illumination strength: 1.5-5.0 µmol/m^2/s (100-200lx)).
- Culture medium: M4
- Feeding: 5 times per week ad libitum with a mix of Scenedesmus subspicatus and Chlorella vulgaris, with an algae cell density of > 10^6 cells/mL.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

232 mg/L

Test temperature:

20 °C

pH:

7.5 - 7.8 at the beginning of the test
7.4 - 7.6 at the end of the test

Dissolved oxygen:

8.4 - 8.5 mg O2/L at the beginning of the test
7.0 - 7.9 mg O2/L at the end of the test

Nominal and measured concentrations:

Based on the results of a preliminary test, the following concentrations were used in the final study:
Nominal test concentrations: 10 mg/L, 18 mg/L, 32 mg/L, 58 mg/L, 100 mg/L
Measured test concentrations recovery rate: not measured, not measured, 108 %, 104 %, 106 %, respectively, based on DOC

Details on test conditions:

TEST SYSTEM
Twenty daphnids were divided into 4 groups with 5 animals per test vessel. 50 mL glass beakers with a fill volume of 20 mL were used. Control replicates (4) without test item were tested under the same conditions as the test groups. Cultures were maintained at 21 +/- 1 °C under a photoperiod of 16 hours light : 8 hours dark (diffuse light, illumination range 1.5-5 µmol/m^2/s
Prior to test start pH-value, dissolved oxygen concentration, conductivity, total hardness and temperature of the dilution water were measured. At the beginning of the test pH value and oxygen concentration were measured in one additional replicate per concentration and control groups, at the end of the same parameters were measured in all replicates per concentration and in the control groups. Temperature was recorded throughout the test with a thermohygrograph.

EFFECT PARAMETERS MEASURED: Daphnia were considered to be immobilised if they were unable to swim for approximately 15 seconds after gentle agitation. Percentage of immobility was determined in all test concentrations and control groups after 24 h and 48 h.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate p.a.

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

52 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Remarks:

DOC

Basis for effect:

mobility

Remarks on result:

other: 95% CL 48-57 mg/L

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

95 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Remarks:

DOC

Basis for effect:

mobility

Remarks on result:

other: 95% CL 90-101 mg/L

Details on results:

Measured concentrations at t=0 ranged from 104 - 108 % of nominal based on DOC analysis.
Individual pH, temperature and dissolved oxygen values remained within acceptable limits throughout
the duration of the study

Results with reference substance (positive control):

24h-EC50: 2.4 mg/L (95% CI: 2.2 - 2.6 mg/L)
The 24h-EC50 vale for the reference item is within the prescribed concentration range of 1.0-2.5 mg/L.

Reported statistics and error estimates:

EC10 and EC50 values were determined by probit analysis.

Table 1 Immobilisation of Daphnia magna (%)

Nominal concentration (mg/L)	Measured concentration (mg/L)	Immobilisation of Daphnia magna (%)
		24 hours					48 hours
Control	-	R1	R2	R3	R4	Mean	R1	R2	R3	R4	Mean
10	N/A	0	0	0	0	0	0	0	0	0	0
18	N/A	0	0	0	0	0	0	0	0	0	0
32	34.5	0	0	0	40	10	0	0	0	40	0
58	60.2	0	0	0	0	0	0	0	40	0	10
100	105.9	40	80	40	100	65	100	100	100	100	100

N/A = not applicable

Table 2 DOC analysis in the new media (0 h)

Nominal test concentration (mg/L)	Nominal total organic carbon (TOC) (mg/L)	Dissolved organic carbon (DOC) analysis (mg/L)		Recovery rate (%)
		New media	Corrected value
100	86.6	74.91	72.63	106
58	39.8	43.58	41.30	104
32	22.0	26.02	23.74	108
Control	-	2.28	-	-

Validity criteria fulfilled:

yes

Remarks:

No daphnids became immobilised in any of the control groups and the dissolved oxygen concentration at the end of the test was >3mg/L in the controls and all test concentrations.

Conclusions:

The Daphnia 48h-EC50 (immobilisation) 52 mg/L.

Executive summary:

The acute Daphnia magna study was conducted in accordance with OECD Guideline for Testing of Chemicals No. 202 and GLP. Four groups of five, 1st instar Daphnia (less than 24 hours old) were exposed for 48 hours to 10, 18, 32, 58 and 100 mg/L of the test substance dispersed in test medium, which were verified using DOC. The incidence of immobilisation was recorded for each test and control group at 24 hours and at 48 hours. Measured concentrations using DOC ranged from 104 - 108 % of nominal at 0 hours. No immobilisation was seen in the control groups, the 10 and 18 mg/L test concentrations. All validity criteria were fulfilled and the study is considered to be valid without restrictions. The Daphnia EC50 was determined to be 95 and 52 mg/Lh at 24 and 48h, respectively. In view of the nominal concentrations being in line with the measured concentrations the results are expressed in terms of nominal concentrations.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2016-2017

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Read across information

Justification for type of information:

The 48h-EC50 for Daphnia endpoint of Ethylphenylglycidate was assessed by using read across from Ethyl 3-methylphenylglycidate. The documentation of this read across can be found attached and in the aquatic endpoint summary.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

52 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CL 48-57 mg/L

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

95 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CL 90-101 mg/L

Validity criteria fulfilled:

yes

Remarks:

Adequate and reliable documentation presented

Conclusions:

For Ethylphenylglycideate the 48h-EC50 Daphnia magna is 52 mg/L.

Description of key information

The 48h Daphnia EC50 is 52 mg/l based on read across from Ethyl 3methylphenylglycidate (OECD TG 202).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

52 mg/L

Additional information

In this section the executive summary of the Daphnia study is presented of the source substance Ethyl 3methylphenylglycidate. The read across rationale is presented in the Aquatic toxicity Endpoint summary.

Ethyl 3methylphenylglycidate and its acute Daphnia toxicity

The acute Daphnia magna study was conducted in accordance with OECD Guideline for Testing of Chemicals No. 202 and GLP. Four groups of five, 1st instar Daphnia (less than 24 hours old) were exposed for 48 hours to 10, 18, 32, 58 and 100 mg/L of the test substance dispersed in test medium, which were verified using DOC. The incidence of immobilisation was recorded for each test and control group at 24 hours and at 48 hours. Measured concentrations using DOC ranged from 104 - 108 % of nominal at 0 hours. No immobilisation was seen in the control groups, the 10 and 18 mg/L test concentrations. All validity criteria were fulfilled and the study is considered to be valid without restrictions. The Daphnia EC50 was determined to be 95 and 52 mg/L at 24 and 48h, respectively. In view of the nominal concentrations being in line with the measured concentrations the results are expressed in terms of nominal concentrations.