4,4'-isopropylidenediphenyl dicyanate

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:

February - June 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Test Substance Name: LZ 514
- Source: Lonza Ltd, Visp/Switzerland
- Lot/batch No. of test material: 5011
- Expiration date of the lot/batch: 2nd December 2017
- Manufacture date: 3rd December 2015

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage conditions: Controlled room temperature (15-25 ºC, below 70 RH%), protected from light and humidity.
- Stability under test conditions: stable
- Safety precautions: Routine safety precautions (lab coat, gloves, safety glasses, face mask) for unknown materials were applied to assure personnel health and safety.

Analytical monitoring:

yes

Details on sampling:

at start and end of each renewal (24h)

Vehicle:

no

Details on test solutions:

Because the Test Item is poorly soluble in water, a test solution was prepared using a saturated solution method according to the Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures, OECD No. 23. A saturated Test Item stock solution (nominal loading rate of 100 mg/L) was prepared by dispersing/dissolving the amount of Test Item into the test medium (ISO Medium) one day before treatment (each renewal period). This solution was shaken for about 24 hours at approximately 30°C and then was equilibrated for about 2 hours at approximately 20°C. The non-dissolved test material was removed by filtration through a fine (0.22 μm) filter to give the 100 % saturated solution. The test solutions were prepared by appropriate dilution of this stock solution just before introduction of the Daphnia (before treatment at each renewal period).

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
- No. of animals: 20 animals in test and control groups respectively, divided into 4 replicates (5 animals / replicate)
- Age of parental stock: less than 24 h old at the beginning of the test
- Feeding during test: no

ACCLIMATION:
There was no acclimatization because the water used was similar to the culture water.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

taking into account that the stability of the test item is not available, the test was performed under semi-static conditions. The frequency of the water renewal periods were 24 hours.

Post exposure observation period:

none

Hardness:

Total hardness of 246 mg/L (as CaCO3)

Test temperature:

The test temperature was in the range of 20.1 – 20.4°C measured in the test vessels. The additionally measured temperature in the climate chamber was between 19.7 – 20.7°C.

pH:

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 7.64 – 7.83.

Dissolved oxygen:

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 7.64 – 7.83.

Salinity:

Fresh water used

Nominal and measured concentrations:

The nominal concentrations of Test Item used in the main experiment were: 1.0, 3.1, 9.8, 31.3 and 100 % saturated solution. Test concentrations were analytically determined at the start and at the end of each renewal period. The corresponding measured geometric mean Test Item concentrations were: 0.00125, 0.00199, 0.00653, 0.04092, 0.17320 mg/L.

Details on test conditions:

Twenty animals, divided into four groups (glass beaker) of five animals each (~ 16 mL test solution/animal) were used.

Reference substance (positive control):

no

Key result

Duration:

24 h

Dose descriptor:

EC50

Remarks:

(95 % confidence limits: 0.0124 – 0.0194 mg/L)

Effect conc.:

0.015 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Remarks:

(95 % confidence limits: 0.0071 – 0.0103 mg/L)

Effect conc.:

0.009 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

0.041 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.007 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

0.041 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Results with reference substance (positive control):

no reference substance tested

Reported statistics and error estimates:

For the determination of the LOEC and NOEC, the immobilization at the test concentrations was tested on significant differences to the control values by Dunnett’s Test using TOXSTAT software.

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of this Daphnia magna acute immobilisation study the calculated and observed endpoints for the effect of the test item were:
- 48h EC50 value: 0.0085 mg/L (measured)
- 48h No-Observed Effect Concentration (NOEC): 0.00653 mg/L (measured)

Executive summary:

The acute toxicity of the test item was assessed in an acute immobilisation test on Daphnia magna, over an exposure period of 48 hours in a semi-static system. Based on the performed preliminary range-finding test five test concentrations in a geometric series with a separation factor of 3.2 and one untreated control were tested in the main experiment. The nominal concentrations of Test Item used in the main experiment were: 1.0, 3.1, 9.8, 31.3 and 100 % saturated solution. Test concentrations were analytically determined at the start and at the end of each renewal period. The corresponding measured geometric mean Test Item concentrations were: 0.00125, 0.00199, 0.00653, 0.04092, 0.17320 mg/L. The biological results are based on the measured concentrations. All validity criteria were met during this study.

The test item was found to be very toxic to aquatic invertebrates (Daphna Magna). The calculated and observed endpoints were:

- 24h EC50 value: 0.0155 mg/L (measured)

- 48h EC50 value: 0.0085 mg/L (measured)

- 48h No-Observed Effect Concentration (NOEC): 0.00653 mg/L (measured)

- 48h Lowest Observed Effect Concentration (LOEC): 0.04092mg/L (measured)

Description of key information

The acute toxicity of the test item was assessed in an acute immobilisation test on Daphnia magna, over an exposure period of 48 hours in a semi-static system. Based on the performed preliminary range-finding test five test concentrations in a geometric series with a separation factor of 3.2 and one untreated control were tested in the main experiment. The nominal concentrations of Test Item used in the main experiment were: 1.0, 3.1, 9.8, 31.3 and 100 % saturated solution. Test concentrations were analytically determined at the start and at the end of each renewal period. The corresponding measured geometric mean Test Item concentrations were: 0.00125, 0.00199, 0.00653, 0.04092, 0.17320 mg/L. The biological results are based on the measured concentrations. All validity criteria were met during this study.

The test item was found to be very toxic to aquatic invertebrates (Daphna Magna). The calculated and observed endpoints were:

- 24h EC50 value: 0.0155 mg/L (measured)

- 48h EC50 value: 0.0085 mg/L (measured)

- 48h No-Observed Effect Concentration (NOEC): 0.00653 mg/L (measured)

- 48h Lowest Observed Effect Concentration (LOEC): 0.04092mg/L (measured)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.009 mg/L

Additional information

Source: GLP-report