Reaction product of Hexamethylene diisocyanate, oligomers with Mercaptopropyltrimethoxysilane

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:

2017-05-30 to 2017-06-01

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)

Version / remarks:

30 May 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

April 2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1010 (Aquatic Invertebrate Acute Toxicity Test, Freshwater Daphnids)

Version / remarks:

1996

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test item is a poorly water soluble material. In order to achieve the maximum solubility level, the test solution was prepared as follows: a supersaturated solution (100 mg/L nominal loading) was prepared by dispersing/dissolving an amount of 0.03 g test item in 300 mL test medium (ISO medium). This solution was agitated by orbital shaker (~350 rpm) for approx. one day and then the non-dissolved test material was separated by filtration through a membrane filter (0.2 µm) in order to obtain the saturated test solution (corresponding to 100 mg/L nominal concentration).
- Controls: Yes, one control group. The dilution water (ISO Medium) was used without addition of the test item.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain/clone: Daphnia magna (Straus)
- Source: Laboratory of Hydrobiology (Central Agricultural Office, Directorate of Plant-, and Soil Protection) 2100 Gödöllő, Kotlán S. u. 3. Hungary
- Age at start: Less than 24 hours old
- Sex. Female
- Feeding during test: None

ACCLIMATION
- Acclimation period: Test animals were bred under similar conditions as that used during the exposure period, therefore additional acclimatisation before the test was not necessary.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

249 mg/L (as CaCO3)

Test temperature:

20.0 - 20.2 °C (measured in the test vessels)
19.7 - 20.7 (within the climate chamber)

pH:

7.72 - 8.33

Dissolved oxygen:

7.62 - 8.18 mg/L

Nominal and measured concentrations:

Nominal concentration: 100 mg/L
No measured concentrations.

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beaker of approximately 40 mL test medium
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted water (ISO medium, according to OECD 202) was used as dilution water in the experiment.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours light (artificial illumination) and 8 hours darkness
- Light intensity: 678 lux

EFFECT PARAMETERS MEASURED: The immobility or mortality of the Daphnia was determined by visual observation after 24 and 48 hours of exposure. Those animals not able to swim within 15 seconds after gentle agitation of the test beaker were considered to be immobile.

RANGE-FINDING STUDY
- Test concentrations: A non-GLP preliminary experiment was carried out at saturation concentration (100 mg/L nominal loading) to determine the approximate toxicity of the test item.
- Results used to determine the conditions for the definitive study: Toxic effects were not observed during the preliminary test, therefore only one test concentration at saturation (equivalent to 100 mg/L nominal concentration) and one control group was tested in a limit test.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

other: EC20

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

There was no immobilisation observed in twenty daphnids exposed to each test item treated and control group. Further no abnormal behaviour or appearance of test animals was noted.

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Relevant effect levels: The 24 h EC50: 1.41 mg/L, (95 % confidence limits: 1.19 – 1.68 mg/L)

Reported statistics and error estimates:

Statistical analysis was not necessary; endpoints were determined directly from the raw data.

Validity of the Study
– The immobilisation rate of the introduced Daphnia did not exceed 10 %. Immobility was not observed in the untreated control and no Daphnia were trapped at the water surface or showed any sign of stress.
– The dissolved oxygen concentration at the end of the test was more than 3 mg/L in control and test vessels.
All validity criteria were within acceptable limits and therefore the study was considered as valid.

Biological Results
There was no immobilisation observed in twenty daphnids exposed to either test item treated or control group. In addition to immobility, no abnormal behaviour or appearance of test animals was detected.
Accordingly, the 48-h NOEC was determined as the saturation concentration (equivalent to 100 mg/L nominal concentration).
The 48-h EC50 and LOEC were determined to be higher than saturation (equivalent to 100 mg/L nominal concentration).

Validity criteria fulfilled:

yes

Conclusions:

In this 48-hour static acute toxicity test on Daphnia magna the test item Reaction product of Hexamethylene diisocyanate, oligomers with Mercaptopropyltrimethoxysilane had no toxic effect on Daphnia at aquatic saturation (equivalent to 100 mg/L nominal concentration). Accordingly, the 48-h EC50 value was determined to be > 100 mg/L. The 48-h NOEC was determined to be 100 mg/L. The results are based on nominal test item concentrations.

Executive summary:

A 48-h acute toxicity test with Daphnia magna was performed according to OECD guideline 202. The test item is a poorly water soluble material and therefore a saturated solution (100 mg/L nominal loading) was prepared and the daphnids were exposed unter static conditions to the test media containing the test item plus a control group for 48 hours. In this 48-hour static acute toxicity test on Daphnia magna the test item had no toxic effect on Daphnia magna at aquatic saturation (equivalent to 100 mg/L nominal concentration). Accordingly, the 48-h EC50 value was determined to be > 100 mg/L. The 48-h NOEC was determined to be 100 mg/L.

Description of key information

In an acute toxicity study with Daphnia magna an 48-h EC50 value of >100 mg/L and a NOEC of 100 mg/L was determined.

Additional information

A 48-h acute toxicity test with Daphnia magna was performed according to OECD guideline 202. The test item is a poorly water soluble material and therefore a saturated solution (100 mg/L nominal loading) was prepared and the daphnids were exposed unter static conditions to the test media containing the test item plus a control group for 48 hours. In this 48-hour static acute toxicity test on Daphnia magna the test item had no toxic effect on Daphnia magna at aquatic saturation (equivalent to 100 mg/L nominal concentration). Accordingly, the 48-h EC50 value was determined to be > 100 mg/L. The 48-h NOEC was determined to be 100 mg/L.