2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one

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:

2002-11-18 to 2003-01-10

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:

1984

Deviations:

no

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:

- Concentrations: duplicate samples from each test medium and control; just before test start, after 48 h
- Sampling method: additional flasks with adequate volumes of the freshly prepared test media of all test concentrations and the control were incubated during the test period under the same conditions as in the actual test
- Sample storage conditions before analysis: All samples were deep-frozen (at about -20 °C) immediately after sampling. Based on preexperiments for invesfigation of the storage stability (without GLP) the test item is sufficienfiy stable in the test water under the storage conditions.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Prior to the start of the test, four individual mixtures with loading rates of 1.0, 2.2, 4.6, and 10 mg/L were prepared. For the dispersion with the loading rate of 1.0 mg/L, the amount of 4.2 mg of the test item was mixed into 4200 mL test water by ultrasonic treatment for 15 minutes and intense sfirring. The dispersions with the loading rates of 2.2, 4.6, and 10 mg/L were prepared by mixing 6.6, 13.8, and 30.1 mg of the test item into 3000 mL test water, respectively. No auxiliary solvent or emulsifier was used. The dispersions were stirred on a magnetic sfirrer at room temperature in the dark for 96 hours to dissolve a maximal amount of the test item in test water.After the stirring period of 96 hours, the dispersions were filtered through a membrane filter just before the start of the test. The filtrates of the dispersions with dissolved test item were tested on the daphnids as WAFs. The WAF with the lowest loading rate of 0.46 mg/L was prepared by dilution of the WAF with the loading rate of 1.0 mg/L due to technical reasons. Addifionally, a control was tested in parallel.
- Eluate: test water
- Differential loading: loading rates of 1.0, 2.2, 4.6, and 10 mg/L
- Controls: yes

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna Straus
- Source: the University of Sheffield/UK in 1992
- Age at study initiation (mean and range, SD): 6-24 hours old
- Method of breeding: the clone is bred in the laboratories of RCC in reconstituted water of the quality idenfical to the water quality used in the tests
- Feeding during test: none
- Food type: none
- Amount: none
- Frequency: none

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

2.5 mmol/L (=250.0 mg/L) as CaCO3

Test temperature:

20 - 21 °C during the test period

pH:

7.8 to 7.9

Dissolved oxygen:

at least 8.2 mg/L

Nominal and measured concentrations:

- loading rates: 0.46, 1.0, 2.2, 4.6, 10 mg/L
- mean measured concentration: 0.42, 0.76, 1.8, 3.9, 5.0 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL glass beakers filled with 50 mL test medium
- Type (delete if not applicable): closed
- Aeration: no aeration
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates):2
- No. of vessels per control (replicates):2
- No. of vessels per vehicle control (replicates): no data
- Biomass loading rate: The loading rate was lower than one daphnia per 2 mL of test solution.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted test water
- Total organic carbon: The test water was aerated until oxygen saturation was reached.
- Alkalinity: 0.8 mmol/L
- Ca/mg ratio: 4 : 1 (based on molarity)

OTHER TEST CONDITIONS
- Photoperiod: The test was performed as far as possible in the dark to avoid photolytic degradation of the test item.


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Influence on the mobility: at the test start, 24 h, 48 h
TEST CONCENTRATIONS
- Spacing factor for test concentrations: The loading rates were based on the results of a range-finding test and on the results of preexperiments
to the solubility of the test item.
- Justification for using less concentrations than requested by guideline: the solubility of the test item
- Range finding study: yes

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.56 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 0.42 to 0.76 mg/L. confidence interval

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

0.42 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.42 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

0.76 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.68 mg/L

Nominal / measured:

nominal

Conc. based on:

other: loading rate

Basis for effect:

mortality

Remarks on result:

other: 0.46-1.0 mg/L confidence interval

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

0.46 mg/L

Nominal / measured:

nominal

Conc. based on:

other: loading rate

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.46 mg/L

Nominal / measured:

nominal

Conc. based on:

other: loading rate

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

1 mg/L

Nominal / measured:

nominal

Conc. based on:

other: loading rate

Basis for effect:

mortality

Details on results:

- Behavioural abnormalities: No significant immobility of the test organisms was determined and in the WAF with the loading rate of 0.46 mg/L. At the loading rate of 0.46 mg/L (mean measured 0.42 mg/L), one test organism was immobile at the observafion after 48 hours. However this immobilizafion rate was not esfimated to be a significant toxic effect because according to the test guidelines, this immobilization rate is also tolerated in the control. At the loading rates of 1.0 to 10 mg/L (mean measured 0.76 to 5.0 mg/L), all daphnids were immobile with the excepfion of 4 daphnids at the loading rate of 2.2 mg/L (mean measured 1.8 mg/L). However, the mobility of these daphnids was also affected.
- Observations on body length and weight: no data
- Mortality of control: none
- Other adverse effects control: no immobility of the test organisms was determined

Reported statistics and error estimates:

The immobility of the daphnids was determined by visual control after 24 and 48 hours of exposure. Those organisms not able to swim within 15 seconds after gentle agitation of the test beaker were considered to be immobile.
The 24-hour and 48-hour EC50 could not be calculated by Probit Analysis or Moving Average Interpolation due to the steep concentrafion-effect relationship. Instead, the EC50 values were determined by linear interpolafion between log-concentrafions and %-immobility.
For the 24-hour EC50, the 95% confidence interval could not be calculated. The test concentrations with 0% and 100% immobility was taken as 95% confidence limits for the 48-hour EC50. The NOEC, ECO, and EC100 were determined directly from the raw data.

Since the test item contains two different isomers, five WAFs (water accommodated fracfions) with loading rates of 0.46, 1.0, 2.2, 4.6, and 10 mg/L were prepared prior to the start of the test. Individual dispersions of the test item in test water with loading rates menfioned above were confinuously stirred at room temperature in the dark over 96 hours to dissolve a maximal amount of the test item in test water. No auxiliary solvent or emulsifier was used. The dispersions were filtered through membrane filters (pore size 0.45 µm) just before the start ofthe test. Addifionally, a control was tested in parallel. The analytically measured test item concentrafions in the test media samples (loading rates 0.46, 1.0, 2.2, 4.6, and 10 mg/L) amounted to 0.39, 0.76, 1.8, 4.0, and 4.9 mg/L at the start of the test (sum of both isomers). In these test media, incubated under the test conditions during the test period (but without daphnia), the concentrations found at the end of the test ranged from 98 to 115% of the inifially measured values. Under the test condifions the test item was stable during the test period of 48 hours. The mean measured test item concentrations (calculated as the average over all measurements per test concentration) were 0.42 mg/L (loading rate 0.46 mg/L), 0.76 mg/L (loading rate 1.0 mg/L), 1.8 mg/L (loading rate 2.2 mg/L), 3.9 mg/L (loading rate 4.6 mg/L), and 5.0 mg/L (loading rate 10 mg/L).

The 48-hour EC50 on the basis of loading rates of the WAFs was calculated to be 0.68 mg/L with a 95% confidence interval from 0.46 to 1.0 mg/L. The 48-hour EC50 on the basis of mean measured test item concentrations was calculated to be 0.56 mg/L with a 95% confidence interval from 0.42 to 0.76 mg/L. The 48-hour EC0 and also the 48-hour NOEC (highest concentrafion tested without toxic effects after 48 hours) of the test item was at the loading rate of 0.46 mg/L (mean measured 0.42 mg/L) since no significant immobilizafion was observed in the test organisms up to and including this loading rate. The 48-hour EC100 was at the loading rate of 1.0 mg/L (mean measured 0.76 mg/L).

Validity criteria fulfilled:

yes

Conclusions:

The test substance is acutely very toxic to aquatic invertebrates.

Executive summary:

In this guideline (OECD 202) study, the 48 hour EC50 of the test material (EC 444-860-9) to Daphnia magna was determined to be 0.56 mg/l (mean measured). The test was conducted under static conditions. The result of this test is sufficient to trigger classification and labelling under the EU Classification, Labelling, and Packaging (CLP) regulation (1272/2008) as H400 (Hazardous to the aquatic environment, Category Acute 1) and [due to the absence of adequate chronic toxicity data] H410 (Hazardous to the aquatic environment, Category Chronic 1).

Description of key information

Study conducted to recognised testing guidelines with GLP certification.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.56 mg/L

Additional information

The acute toxicity of the test substance to the water flea Daphnia magna was determined according to the OECD guideline 202 (RCC Ltd., 2003). The test was performed under static conditions. Since the test item contains two different isomers, five WAFs (water accommodated fractions) with loading rates of 0.46, 1.0, 2.2, 4.6, and 10 mg/L have been tested. The test concentrations were analytically verified at the beginning and at the end of the test. The test substance was stable during the test period.

After 48 hours an EC50 value of 0.56 mg/L mean measured (= 0.68 mg/L loading rate) was determined. The NOEC/EC0 was determined to be 0.42 mg/L mean measured (= 0.46 mg/L loading rate) after 48 h. The test substance is acutely very toxic to aquatic invertebrates.