Phosphoric acid, ethyl ester

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2001-01-08 - 2001-03-19

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Ethyl dihydrogen phosphate

EC Number:

216-603-9

EC Name:

Ethyl dihydrogen phosphate

Cas Number:

1623-14-9

Molecular formula:

C2H7O4P

IUPAC Name:

Phosphoric acid,monoethyl ester

Test material form:

liquid

Specific details on test material used for the study:

Phosphoric acid mono-/di-ethylesterChemical name:
Molecular formula: x C2H7O4P * y C4H11O4P
CAS-Number: 1623-14-9,598-02-7

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Details on test solutions:

The test substance was weighed into a beaker, mixed with water for dilution and homogenized with the Ultra-Turrax to ensure that the solubility limit of the test substance in the test water is reached.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Species
Daphnia magna - Clone 5 {IRChA, France)
Origin
Stock culture of Aventis Pharma Deutschland GmbH, ProTox
Breeding conditions
100 mL beakers (height 90 mm, diameter 50 mm), filled with 70 mL test water (according to Elendt, M4) served as culture vessels. One daphnid was used per culture vessel. The animals were used for breeding up to an age of 42 days. The reproduction rate and the state of health of the animals were monitored daily apart from weekends. The animals were fed three times a week with monocellular green algae {Scenedesmus subspicatus).
The supplied diet was based on the amount of organic carbon (C), The ration level is 0.2 mg carbon / day / animal.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Hardness:

The total hardness of the dilution water was 2.1 mmol Ca2+ + Mg2+ / L during the study.

Test temperature:

20.3-21.1 °C

pH:

6.1-6,3

Dissolved oxygen:

8.5-8.8 mg/l

Nominal and measured concentrations:

100 mg/l nominal
103 mg/l measured

Details on test conditions:

After the test concentrations had been prepared and water parameters were recorded, 10 daphnids were used in each test chamber. The daphnids were not fed during the entire study period. Inspection of the daphnids took place after 24 and 48 hours and involved recording the immobility. Immobile daphnids were removed from the chambers. Those animals which were not able to swim within 15 seconds after gentle agitation of the test container were considered to be immobile. The water parameters were measured after adding the substance and at the end of the test.

Results and discussion

Effect concentrations

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

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In this 48-hour acute toxicity study of Hordaphos MDE rn Daphnia magna (water flea) no immobility occurred in the 100 mg/L-group (nominal concentration) and in the control group.

Under the conditions of this test the EC50 of Hordaphos MDE after 48 hours was 100 mg/L.

Executive summary:

Hordaphos MDE was tested in Daphnia magna (water flea) for 48 hours in a static system. The concentration tested was 100 mg/L and a control (0 mg/L). The tested concentration was present as a clear solution. All test batches were homogeneous. No particulate matter was observed. The substance concentration was determined in the 100 mg/L group. The values determined were in a range of + 10 % of the theoretical value.

In this 48-hour acute toxicity study of Hordaphos MDE the following immobility values were determined:

	after 24 hours	after 48 hours
ECo (mg/L)	> 100	> 100
EC5o (mg/L)	> 100	> 100
EC-1oo (mg/L)	> 100	> 100

The 100 mg/L group showed no effect in comparison to the negative control.