4,4'-methylenebis(2,6-diisopropylaniline)

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:

January 2015

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

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

At start and end of each renewal period (renewal after 24 h)

Vehicle:

no

Details on test solutions:

The test solution used in the test was prepared by mechanical dispersion without using of any solubilising agent. In order to achieve maximum dissolved concentration, a supersaturated solution was prepared by dispersing/dissolving an appropriate amount of test item into the test medium (ISO medium): 0.36 g / 500 mL in the first renewal period and 0.37 g / 500 mL in the second renewal period of the study. This solution was agitated by orbital shaker (~300 rpm) for a period of 20 hours and then the non-dissolved test material was separated by filtration through a fine (0.22 μm) filter in order to obtain the saturated test solution. The test solution was prepared just before introduction of the test animals (start of the water renewal periods).

Test organisms (species):

Daphnia magna

Details on test organisms:

- Sex: female
- Age of animals: less than 24 h old at the beginning of the test
- Origin: Laboratory of Hydrobiology, 2100 Gödöllő, Kotlán S. u. 3. Hungary
- Breeding: bred in the Laboratory of TOXI-COOP ZRT.
- Acclimatization: animals bred under similar conditions during exposure, therefore acclimatisation before testing was not needed
- Animal health: apparently healthy animals with a known history (breeding method, pre-treatment)
- Number of animals: 20 animals in each group (test group and untreated control) divided into 4 replicates
- Food and Feeding: fed with concentrated algal suspension of Pseudokirchneriella subcapitata during holding. Test animals not fed during exposure

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

Reconstituted water (ISO medium) has an approximate theoretical total hardness of 249 mg/L (as CaCO3).

Test temperature:

Test temperature was in the range of 19.9 – 20.5°C measured in the test vessels during the test.

pH:

pH of the test solution was not adjusted and not varied by more than 1.5 units in any one test. The pH was in the range of 7.63 – 7.95 during the test.

Dissolved oxygen:

Dissolved oxygen concentration was in the range of 7.77 – 8.55 mg/L during the test.

Salinity:

Freshwater used.

Nominal and measured concentrations:

Based on the results of the preliminary experiment nominal concentration of 100 % v/v saturated solution was tested in the main study. The corresponding calculated geometric mean test item concentration (based on the analytical measurements) was 0.13 mg/L. At the end of the first renewal period, the measured test item concentration was 61 % of the measured concentration at the start of the period while at the end of the second renewal period the measured test item concentration was 60 % of the measured concentration at the start of the period.
There is evidence that the concentration of the tested substance was not maintained within 20 % of the start concentrations throughout the test, therefore the analysis of the results was based on the geometric mean concentration values. All reported biological results are related to the measured concentrations of the test item.

Details on test conditions:

Based on the analytical results the test item was not expected to be stable for the duration of 48 hours in ISO Medium, therefore a semi-static test was performed using daily water renewal periods.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.13 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 0.13 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.13 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 0.13 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Results with reference substance (positive control):

For the evaluation of the quality of the Daphnia clone and the experimental conditions, Potassium dichromate is tested at least twice a year to demonstrate satisfactory test conditions. The date of the last study with reference item Potassium dichromate was: September 24 - 25, 2014. The 24-h EC50: 1.40 mg/L, (95 % confidence limits: 1.19 – 1.68 mg/L)

Reported statistics and error estimates:

No toxic effect was observed during the study, therefore using of statistical analysis was not necessary to evaluate the biological results. The 48-h EC50, NOEC, LOEC and EC100 values were determined directly from the raw data.

Validity criteria fulfilled:

yes

Conclusions:

Based on the results of this study, the test item has no toxic effect on Daphnia magna up to at least the solubility limit of the test item in the test medium (0.13 mg/L measured). The 48-h NOEC was determined to be the saturation concentration, the EC50 results and the LOEC are higher than the saturation concentration (0.13 mg/L measured).

Executive summary:

Acute toxicity of the test item was assessed on Daphnia magna in a 48 -hour Acute Immobilisation test according to OECD 202. Young Daphnia were exposed to aqueous test media containing the test item for 48 hours at the concentration equal to the water solubility (water accommodated fraction, i.e. WAF). Based on the analytical results the test item was not expected to be stable for the duration of 48 hours in ISO Medium, therefore a semi-static test was performed using daily water renewal periods.

Based on the results of this study, the test item has no toxic effect on Daphnia magna up to at least the solubility limit of the test item in the test medium (0.13 mg/L measured). The 48-h NOEC was determined to be the saturation concentration, the EC50 results and the LOEC are higher than the saturation concentration (0.13 mg/L measured).

Description of key information

Acute toxicity of the test item was assessed on Daphnia magna in a 48 -hour Acute Immobilisation test according to OECD 202. Young Daphnia were exposed to aqueous test media containing the test item for 48 hours at the concentration equal to the water solubility (water accommodated fraction, i.e. WAF). Based on the analytical results the test item was not expected to be stable for the duration of 48 hours in ISO Medium, therefore a semi-static test was performed using daily water renewal periods.

Based on the results of this study, the test item LZ 53 has no toxic effect on Daphnia magna up to at least the solubility limit of the test item in the test medium (0.13 mg/L measured). The 48-h NOEC was determined to be the saturation concentration, the EC50 results and the LOEC are higher than the saturation concentration (0.13 mg/L measured).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.13 mg/L