2-phenoxyethanol; phosphoric acid

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:

2018-05-16 to 2018-05-18

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

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1010 (Aquatic Invertebrate Acute Toxicity Test, Freshwater Daphnids)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

- CAS number: 39464-70-5
- Appearance: Clear, yellow liquid
- Batch No.: M-1025-157
- Purity: 100%
- Expiry date: 25 October 2018
- Storage conditions: Room temperature (15-25 °C, ≤ 70 % relative humidity (RH))
- Safety precautions: Routine safety precautions (gloves, goggles, face mask, lab coat) for unknown materials were applied to assure personnel health and safety

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 100, 50, 25, 12.5, 6.25, 0 mg/L
- Sampling method: Analytical measurements were performed from the Control and at the applied test concentration levels at the beginning and at the end of the exposure.

Vehicle:

yes

Remarks:

Reconstituted water (ISO medium, according to OECD 202) was used as dilution water for both the range finding and definitive tests.

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The Test Item is an UVCB and soluble in the test media, therefore a stock solution with the concentration of 100 mg/L (nominal) was prepared with Test Item and test medium (ISO medium) by direct addition, with mixing and using ultra-sonication as needed. The test solutions were prepared by appropriate dilution of this stock solution just before introduction of the Daphnia (start of the experiment).

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Source: Szent István University, Department of Aquaculture, 2100 Gödöllő, Páter Károly u. 1., Hungary
- Age of animals: They were less than 24 h old at the beginning of the test

ACCLIMATION
- Acclimation conditions (same as test or not): There was no acclimatization because the water used was similar to the culture water.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

The reconstituted water (ISO medium) had a total hardness of 247 mg/L (as CaCO3).

Test temperature:

The water temperature was measured at the start and at the end of each renewal period in each test vessel. The test temperature was in the range of 20.1 – 20.9 °C measured in the test vessels. The additionally measured temperature in the climate chamber was between 20.2 – 20.8 °C.

pH:

The pH of the test solution was not adjusted and not varied by more than 1.5 units in any one test. The pH was measured at the start and at the end of each renewal period in each test vessel and was in the range of 7.10 – 7.86.

Dissolved oxygen:

The dissolved oxygen concentration was measured in each test vessel at the start and at the end of each renewal period and was in the range of 7.9 – 8.4 mg/L.

Salinity:

n.a.

Conductivity:

n.a.

Nominal and measured concentrations:

- nominal: 100, 50, 25, 12.5, 6.25, 0 mg/L
- measured: 117.2, 59.5, 28.7, 14.0, 7.4, 0 mg/L (geometric mean)

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beaker
- Type of flow-through: static
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per vehicle control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted water (ISO medium, according to OECD 202). Separate stock solutions of individual trace elements were first prepared in deionised water. The medium was prepared of these different stock solutions, so it contains all trace elements at 25 mL/L (CaCl2, MgSo4, KCl, NaHCO3)

OTHER TEST CONDITIONS
- Adjustment of pH: The pH of the test solution was not adjusted and not varied by more than 1.5 units in any one test. The pH was measured at the start and at the end of each renewal period in each test vessel and was in the range of 7.10 – 7.86
- Photoperiod: The test was carried out in 16-hour light and 8-hour dark cycle

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
The immobility or mortality of the Daphnia was determined by visual observation 24 and 48 hours after the start of the test. Those animals not able to swim within 15 seconds after gentle agitation of the test beaker are considered to be immobile.
The number of immobilised animals and the percentage of immobility were determined at 24 and 48 hours.

VEHICLE CONTROL PERFORMED: yes (water)

RANGE-FINDING STUDY
A concentration range-finding test was conducted to determine the approximate toxicity of the Test Item so that appropriate test concentrations could be selected for use in the definitive test. Ten daphnids (divided into two replicates) in each test concentration (100, 10, 1 and 0.1 mg/L) and control were exposed for 48 hours under semi-static conditions.
- Results used to determine the conditions for the definitive study: Yes

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (tested twice per year)

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:

48 h

Dose descriptor:

EC100

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

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:

Based on the results of this study, the Test Item had no toxic effect at 100 mg/L on the Daphnia therefore; based on the measured concentrations, the EC50 and the LOEC results are > 100 mg/L in the test medium.

Results with reference substance (positive control):

n.a.

Reported statistics and error estimates:

No statistical analysis was performed because of the lack of toxic effects on the Daphnia. The EC50, NOEC, LOEC and EC100 values were determined directly from the raw data. As all validity criteria were met during this study.

VALIDITY:

There was no immobilized animal in the Control group and the dissolved oxygen concentration at the end of the test in Control and test vessels was more than 3 mg/L. All validity criteria were within acceptable limits and therefore the study is considered as valid.

CONCENTARTIONS OF THE TEST ITEM:

The following nominal concentrations were tested: 6.25, 12.5, 25, 50 and 100 mg/L (nominal). All nominal concentration could be quantified during the study. There was no Test Item detected in the Control samples. The corresponding measured geometric mean Test Item concentrations were: 7.04, 14.0, 28.7, 59.5 and 117.2 mg/L, hence the highest concentration is considered to be >100 mg/L. The biological results are based on the measured concentrations. Since the starting concentration at the highest concentration was approximately 100 mg/L and there was no decrease in concentration, the concentration is considered to be >100 mg/L (the limit concentration for this test). The measured concentration at 48 hours appeared to be significantly above 100 mg/L, the reason for this is not known but logically the concentration cannot increase with time; but this has no influence on the study outcome when the concentration is considered to be >100 mg/L.

Validity criteria fulfilled:

yes

Conclusions:

In an acute toxicity test according to the OECD guideline 202 with Daphnia magna an 48 hr EC50 of > 100 mg/mL (nominal) was determined for Ethoxylated phenol phosphate.

Executive summary:

The 48-hr-acute toxicity of Ethoxylated phenol phosphate to Daphnia magna was studied under static conditions according to OECD test guideline 202. Daphnids were exposed to concentrations of 0, 6.25, 12.5, 25, 50 and 100 mg/L (nominal) for 48 hours. The test item had no toxic effect at 100 mg/mL on the Daphnia and therefore, based on the measured concentrations, the 48-hour EC50 based on immobilization was > 100 mg/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 (e.g. 1st instar): < 24 h

Test Type (Flowthrough, Static, Static Renewal): Static

NOEC: 100 mg/L (nominal)

EC50/LOEC: > 100 mg/L (nominal)

Description of key information

In an Acute Immobilisation Test conducted according to the OECD guideline 202 Daphnia magna were exposed to 100 mg/L Ethoxylated phenol phosphate. During this test no effects were observed regarding mortality and mobility. A 48-hr EC50 was therefore reported to be above 100 mg/L. As the measured concentrations did not deviate more than ± 20% of the nominal, the biological results are based on the nominal concentrations.

The 48-h EC50 value: >100 mg/L (nominal)

The 48-h NOEC: 100 mg/L (nominal)

The 48-h LOEC: >100 mg/L (nominal)