[No public or meaningful name is available]

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:

02/10/2008-10/02/2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP study performed according to OECD 202 guideline

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

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

ANALYSIS OF THE TEST ITEM CONCENTRATIONS
For the determination of the actual test item concentrations, duplicate samples were taken from each treatment before the start of the test and at the end of the test after 48 hours. For the 48-hour stability samples, the contents of the respective replicates were combined prior to sampling.
All samples were stored deep-frozen (at about -20 °C) immediately after sampling. Based on preexperiments for investigation of the storage stability (non-GLP), the test item was found to be sufficiently stable in the test water under these storage conditions.
The concentrations of the test item were analyzed in the duplicate test media samples from the nominal concentrations of 0.14 to 0.63 mg/L from both sampling times (0 and 48 hours). From the control, only one of the duplicate samples was analyzed from each of
the sampling times.
The samples of the nominal test concentrations of 1.4 and 3.0 mg/L were not analyzed since the same high toxic effect (EC100) was determined at the lower nominal concentration of 0.63 mg/L.
These test concentrations were therefore not considered to belong to the relevant part of the concentration-effect curve.

WATER QUALITY CRITERIA
At the start and end of the test, the pH values, dissolved oxygen concentrations and water temperature were determined at each test concentration and in the control. The appearance of the test media was visually recorded at the start of the test and after 24 and 48 hours.

Vehicle:

no

Details on test solutions:

DOSAGE
A stock solution with a nominal concentration of 30 mg/L was prepared by completely dissolving 30.0 mg of the test item in 1000mL of test water using ultrasonic treatment for 5 minutes and intense stirring for 5 minutes at room temperature. This intensively mixed stock solution was used in a series of dilutions to prepare the test media of all test item concnetrations.
The test was performed in 100mL glass beakers filled with 50mL of test medium.

Test Water
Reconstituted test water according to ISO 6341 was used in the study. It consisted of analytical grade salts dissolved in purified water.
The ratio of Ca:Mg and Na:K was 4:1 and 10:1, respectively, based on molarity.
The test water was aerated prior to the start of the study until oxygen saturation was reached.
During the test period, the test water was not aerated.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Source: University of Sheffield/UK
- Age at study initiation (mean and range, SD): 6-24 hours old

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

250 mg/L as CaCO3

Test temperature:

20-21ºC

pH:

7.9

Dissolved oxygen:

8.7mg/L

Nominal and measured concentrations:

Nominal concentrations: 0.14, 0.30, 0.63, 1.4 and 3.0 mg/L.
The selection of the test concentrations was based on the results of a range-finding test and on results of a pre-experiment to determine the solubility of the test item in the test water (non-GLP).

Details on test conditions:

Experimental Conditions
The test was performed in a temperature-controlled room with continuous monitoring of the room temperature. The water temperature was maintained at 20-21 °C. A 16-hour light to 8-hour dark cycle with a 30-minute transition period was used. Light intensity during the light period was approximately between 500 and 630 Lux. The daphnids were not fed during the test.

For each treatment, 20 daphnids were used divided into four replicates of five daphnids each. The volume of test solution provided for each daphnia was 10mL. Thus, the requirements of the test guideline for the minimum volume of 2 mL test medium per daphnia was fulfilled. The daphnids were randomly distributed to the test vessels at initiation of the test.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

0.32 mg/L

Conc. based on:

test mat.

Remarks on result:

other: 0.20-0.50 mg/L

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

0.2 mg/L

Conc. based on:

test mat.

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

0.5 mg/L

Conc. based on:

test mat.

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.32 mg/L

Conc. based on:

test mat.

Remarks on result:

other: 0.20-0.50 mg/L

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

0.2 mg/L

Conc. based on:

test mat.

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.2 mg/L

Conc. based on:

test mat.

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

0.5 mg/L

Conc. based on:

test mat.

Details on results:

During the 48 hours of the test, no significant number of immobilized test organisms were determined in the control and up to and including the test concentration of 0.20 mg/L. However, in the control and at the test concentration of 0.20 mg/L one daphnia was observed to be immobile after 48 hours. The low immobilization of 5% at the test concentration of 0.20 mg/L was not estimated as a significant toxic effect because according to the test guidelines a 10% immobilization in the control is accepted for the test to be valid. From the test concentration of 0.50 mg/L onwards, 100% immobilization of the daphnids was observed.
The 24-hour and 48-hour EC50 of the test item was calculated to be 0.32 mg/L with 95% confidence limits of 0.20 and 0.50 mg/L. The 24-hour and 48-hour EC0 and NOEC were
0.20 mg/L. The 24-hour and 48-hour EC100 were 0.50 mg/L. Thus, the dosage-response relationship in this test was rather steep.

Results with reference substance (positive control):

For evaluation of the quality of the daphnia clone and the experimental conditions, potassium dichromate is tested as a positive control twice a year. The result of the latest positive control test in March 2008 (48-hour EC50: 0.73 mg/L, RCC Study No. B83744) indicated that the sensitivity of the test organisms was within the historical range of the RCC laboratory (48-hour EC50 from1996 to 2008: 0.53-1.1 mg/L).

Reported statistics and error estimates:

The 24- and 48-hour EC50 could not be calculated by Probit Analysis or Moving Average Interpolation due to the steep concentration-effect relationship. Instead, the 48-hour EC50 was determined as the geometric mean value of the two consecutive test concentrations with 0 and 100% immobility (EC0 and EC100), and the confidence limits for the EC50 as the test concentrations with 0 and 100% immobility.
The NOEC, EC0 and EC100 were determined directly from the raw data.

No remarkable observations were made concerning the appearance of the test media. All test media were clear solutions throughout the entire test duration.

At the beginning and end of the test period, the dissolved oxygen concentrations in the test media and control were at least 7.6 mg/L, the pH value of the test media was between 7.8 and 7.9, and the water temperature during the test was 20-21 °C.

Validity criteria fulfilled:

yes

Conclusions:

Under the test conditions, the 48h-EC50 of the registered substance to Daphnia magna was found to be 0.32 mg/L, based on the mean measured test item concentrations.

Executive summary:

The acute toxicity of the test item of the substance to Daphnia magna was determined in a 48 -hour static test according to the OECD 202 and under GLP compliance.

The nominal test item concetrations tested were 0.14, 0.30, 0.63, 1.4 and 3.0 mg/L. Additionally, a control group was tested in parallel.

At the start of the test, the analytically determination concentrations of the test item in the test media of nominal 0.14 to 0.63 mg/L were between 73 and 101% of the nominal values. During the test period of 48 hours, a decrease of test item concentration in the test media was determined. At the end of the test, 36 to 62% of the nominal values were found. The mean measured test concentrations (calculated as the geometric means of the concentrations measured at the start and the end of the test) were 0.071mg/L (nominal 0.14 mg/L), 0.20 mg/L (nominal 0.30 mg/L), and 0.50 mg/L (nominal 0.63 mg/L).

The reported biological results were based on the mean measured test item concentrations.

– 24-hour EC50: 0.32 mg/L (95% confidence limits: 0.20 and 0.50 mg/L)

– 24-hour EC0: 0.20 mg/L

– 24-hour EC100: 0.50 mg/L

– 48-hour EC50: 0.32 mg/L (95% confidence limits: 0.20 and 0.50 mg/L)

– 48-hour EC0 0.20 mg/L

– 48-hour NOEC: 0.20 mg/L

– 48-hour EC100: 0.50 mg/L

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

16/09/1991-18/09/1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

According to the OECD Guideline 202 but it is not GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

no

Analytical monitoring:

not specified

Vehicle:

no

Details on test solutions:

The preparation of stock solution with a concentration of 1g/L of test susbtance was done by dilution with reconstituted water according to DIN 38412, part 30.

Test organisms (species):

Daphnia magna

Details on test organisms:

- Breeding method: Daphnia are held in drinking water at room temperature (20 +/- 2°C) with 16h photoperiod daily. Daphnia are sieved every day, so that the animals used for the test are not more than 24 hours old.
- Feeding: Every 24 hours ad lib. with Scenedesmus cells.

Test type:

static

Water media type:

not specified

Limit test:

no

Total exposure duration:

48 h

Nominal and measured concentrations:

0; 0.125; 0.25; 0.5; 1; 2; 4; 8 and 16 mg/L.

Details on test conditions:

The test conditions were as follows: static test for 48 hours at 20±1ºC. Four test vessels involved 5 Daphnia each are run in parallel for every test concentration.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

1 mg/L

Conc. based on:

test mat.

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

0.5 mg/L

Conc. based on:

test mat.

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

2 mg/L

Conc. based on:

test mat.

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

1 mg/L

Conc. based on:

test mat.

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

4 mg/L

Conc. based on:

test mat.

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

2 mg/L

Conc. based on:

test mat.

Validity criteria fulfilled:

yes

Conclusions:

Under the test conditions, the EC50 (48h) of the test item to Daphnia was found to be 1 mg/L. The EC50 value was determined by calculation of the geometrical mean value.

Executive summary:

The acute toxicity of the test item to aquatic invertebrate Daphnia magna was determined in a non-GLP 48-hour test according to the OECD Guideline for Testing of Chemicals No. 202.

The Daphnia are exposed to various concentrations of the test substance for 48hours. After 24h and 48h the percentage of animals incapable of swimming is recorder. pH-value, water temperature and dissolved oxygen concentration are measured at the beginning and at the end of each test. A range-finding test is performed in advance. The concentrations of the test substance in the range-finding test vary with a factor of 10 each. Concentrations for the definitive test are chosen according to the results of the range-finding tests: 0; 0.125; 0.25; 0.5; 1; 2; 4; 8 and 16 mg/L.

The test conditions were as follows: static test for 48 hours at 20±1ºC. Four test vessels involved 5 Daphnia each are run in parallel for every test concentration. The preparation of stock solution with a concentration of 1g/L of test susbtance was done by dilution with reconstituted water according to DIN 38412, part 30.

Under the test conditions, the EC50 (48h) of the test item to Daphnia was found to be 1 mg/L. The EC50 value was determined by calculation of the geometrical mean value.

In addition, the EC0 and the EC100 were 0.5 and 2 mg/L respectively.

Description of key information

A reliable study was available to assess the acute toxicity of the test item to Daphnia magna in a 48-hours static test according to the OECD Guideline 202 and in compliance with GLP.

Under the test conditions, the 48h-EC50 of the registered substance to Daphnia magna was found to be 0.32 mg/L, based on the mean measured test item concentrations.

This study was considered acceptable for that endpoint.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.32 mg/L

Additional information

Moreover, a supporting study that assesses the acute toxicity of the test item to thae aquatic invertebrate Daphnia has been added to the dossier. This non-GLP study was performed according to the OECD Guideline for Testing of Chemicals No. 202.

Under the test conditions, the EC50 (48h) of the test item to Daphnia was found to be 1 mg/L. The EC50 value was determined by calculation of the geometrical mean value.