PDI oligomers, isocyanurate (3x)

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 September - 20 October 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2018

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

2004

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

2008

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

1996

Deviations:

no

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: HJ/T 153-2004, The guidelines for the testing of chemicals, Beijing: SEPA

Version / remarks:

2004

Deviations:

no

Test guideline 5

Qualifier:

according to guideline

Guideline:

other: CRC-MEP, The Guidelines for the Testing of Chemicals, Effects on Biotic Systems, The 2nd edition. Beijing: China Environment Press. 2013:22-29.

Version / remarks:

2nd edition

Deviations:

no

Test guideline 6

Qualifier:

according to guideline

Guideline:

other: GB/T 21830-2008, Chemicals-Daphnia magna acute immobilisation test, Beijing: SAC

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

1,3,5-tris(5-isocyanatopentyl)-1,3,5-triazinane-2,4,6-trione

Cas Number:

119934-71-3

Molecular formula:

C21 H30 N6 O6

IUPAC Name:

1,3,5-tris(5-isocyanatopentyl)-1,3,5-triazinane-2,4,6-trione

Constituent 2

Reference substance name:

2-methylpropyl N-(5-isocyanatopentyl)-N-(5-isocyanatopentylcarbamoyl)carbamate

Molecular formula:

C18 H30 N4 O5

IUPAC Name:

2-methylpropyl N-(5-isocyanatopentyl)-N-(5-isocyanatopentylcarbamoyl)carbamate

Test material form:

liquid: viscous

Details on test material:

Appearance: colourless or light yellow viscous liquid
Storage conditions: at room temperature, container tightly closed, flushed with nitrogen.

Specific details on test material used for the study:

Solubility <0.394 mg/L (at 20°C)

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Samples of 10 mL were taken from the blank control and the limit concentration for analysis at t=0, t=24 and t=48.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: WAFs were prepared by adding the test substance directly to Elendt M7 medium in glass aspirator bottles at the required loading rates. The mixing aspirator bottle was stoppered and the aqueous test substance mixture was stirred for 24 hrs on a magnetic stirplate with a Telfon stirbar at room temperature. At the end of the 24 h, the mixtures were left to settle for 1 h at room temperature. Then the aqueous portion was removed through the outlet of the aspirator stirring bottle.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia
- Source: Nanjing University, Lot no. D20170925D and D20171017D (for dose-range finding and limit study, resp.)
- Age of parental stock: Daphnia magna (<24 hours old) were more than three generations through parthenogenesis.
- Feeding during test: no

ACCLIMATION: no

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Test temperature:

19.7 - 20.4 °C

pH:

7.34 - 7.83 throughout the test

Dissolved oxygen:

8.34 - 8.82 mg O2/L throughout the test

Nominal and measured concentrations:

Nominal concentration: WAF prepared at a loading rate of 100 mg/L
Measured concentrations: 20.4 mg/L at t=0 h, 19.5 mg/L at t=24 h and 21.9 mg/L at t=48 h. The mean measured concentration was calculated to be 20.6 mg/L.

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL glass beakers, fill volume: 50 mL
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Test medium: Elendt M7
- Intervals of water quality measurement: pH, dissolved oxygen and temperature in the controls and treatment groups were monitored at the beginning and end of the test.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16-hour light, 8-hour dark

EFFECT PARAMETERS MEASURED: immobilisation at t=24 h and t=48 h
- Other: any abnormal behaviour or appearance was reported at t=24 and t=48 h.

RANGE-FINDING STUDY
- Test concentrations: WAFs prepared at loading rates of 1.00, 10.0 and 100 mg/L.
- Results used to determine the conditions for the definitive study: yes, no immobilisation was observed up to and including the highest tested concentration. The EC50 was expected to be >100 mg/L and therefore a limit test using this concentration was performed.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 20.6 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mobility

Effect concentrations 2

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

20.6 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mobility

Details on results:

- No daphnids became immobilised during the limit test. Therefore, the NOEC was the highest tested concentration and the EC50 exceeded the highest tested concentration.
- No abnormal behaviour or other abnormalities were observed during the limit test.
- Test concentrations remained stable during the test period. Since the initial measured test concentration was outside the range 80-120% of the nominal concentration, the effect concentrations were based on the mean measured concentration.

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- 48h-EC50: 1.03 mg/L (95% CI: 0.87-1.23 mg/L)

Reported statistics and error estimates:

The EC50 and 95% confidence limits were calculated by Trimmed Spearman-Karber Method (Version 1.5, USEPA).

Any other information on results incl. tables

Table 1 Measured concentrations in samples taken during the limit test

Nominal Concentration (mg/L)	Measured TOC Concentration(mg/L)			Mean
	0h	24h	48h
blank control	9.75	9.66	9.40	9.60
100 mg/L	20.4	19.8	20.8	20.3
Deduct blank control TOC value	10.7	10.1	11.4	10.7
Concentration of test subtstance	20.4	19.5	21.9	20.6

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

see 'overall remarks' section

Conclusions:

In the toxicity to daphnia study, performed according to OECD guideline 202 and GLP principles, the EC50 of STABiO D-376N was determined to be >20.6 mg/L.

Executive summary:

In a short-term toxicity test, performed according to OECD guideline 202 and GLP principles, STABiO D-376N was assessed for its potential toxicity towards Daphnia magna. Test solutions were prepared as Water Accomodated Fractions (WAFs) for a dose-range finding study and a limit study. The dose-range finding study was performed with WAFs prepared at loading rates of 1.0, 10 and 100 mg/L. Since no immobility of the daphnids was seen at any tested concentration, the final test was performed as a limit test with a WAF prepared at a loading rate of 100 mg/L. The test solution was tested in 4 replicate vessels containing 5 daphnids each, next to 4 replicates of a blank control. The exposure period was 48 hours and the test was performed under static conditions. Samples were taken from the test solution at t=0, t=24 and t=48 h for determination of actual exposure concentrations by TOC analysis. The test concentration showed to remain stable over the test period and therefore effect concentrations were based on the mean measured concentration which was calculated to be 20.6 mg/L. No immobility or abnormal behaviour was observed in the daphnids during the exposure period. Therefore, the 48h-EC50 for Daphnia magna exposed to STABiO D-376N was determined to be >20.6 mg/L.

The acceptability criteria were met and the study was considered to be valid.