1,3,5-tris[3-(trimethoxysilyl)propyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione

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:

Exposure phase: 2018-09-11 to 2018-09-13. Study period: 2018-09-10 to 2018-09-13

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Substance analysis determined concentration of parent, not hydrolysis product

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

Fulfilled the test guideline validity criteria

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Remarks:

The samples were implemented under non-GLP and documented in the GLP raw data. The method was validated according to Annex I.

Details on sampling:

- Concentrations: 0 and 100mg/l
- Sampling method: At the start of the exposure (0 hours), two aliquots as samples of the fresh media (control and limit loading) were taken after preparation of the limit loading, diluted by factor 2 with methanol and analyzed.
At the end of the exposure (48 hours), two aliquots as samples of the old media (control and limit loading) were taken directly from the test vessels, diluted by factor 2 with methanol and analysed.

- Sample storage conditions before analysis: All samples were stored at room temperature until the start of the analysis, if necessary. Prepared samples were stored in the autosampler at room temperature until analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A bottle was filled with 2000 mL of the dilution water and 170.9 µL of the test item (density: 1.17 g/cm³ was taken into account; purity not taken into account) were placed by pipette below the water surface. The bottle was closed with a screw cap. The test item solution was stirred with a magnetic stirrer at approximately 1100 rpm for 24 ± 1 hours at room temperature. After a separation phase of 1 hour, the test item solution was removed by siphoning (from the approximate middle, 2/3 of height, of the glass flask). The resulting saturated solution was once again stirred for 2 hours at approx. 1100 rpm at room temperature. Thereafter, the test item solution was checked via laser beam (Tyndall effect) for undissolved test item (formation of an emulsion). No Tyndall effect was observed. Therefore, the test item solution (saturated solution) was used for testing without filtration.
- Eluate: Not reported
- Differential loading: Not reported
- Controls: Dilution water without test item incubated under the same conditions as the test group.
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): The test item solution was checked via laser beam (Tyndall effect) for undissolved test item (formation of an emulsion). The solution was clear and colourless.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: obtained from continuous laboratory culture at Noack Laboratorien GmbH
Käthe-Paulus-Str. 1, 31157 Sarstedt, Germany. Original source: Institut für Wasser-, Boden- und Lufthygiene (WaBoLu), 14195 Berlin, Germany
- Age of parental stock (mean and range, SD): Not reported
- Feeding during test: The daphnids were not fed during the study.
- Food type: Not applicable
- Amount: Not applicable
- Frequency: Not applicable

ACCLIMATION
- Acclimation period: Acclimatisation of the daphnids was not necessary, because the composition of the dilution water was equivalent to the culture medium.
- Acclimation conditions (same as test or not): Not applicable
- Type and amount of food: Not applicable
- Feeding frequency: Not applicable
- Health during acclimation (any mortality observed): not applicable

CULTURE
In glass vessels (2 - 3 L capacity) with approximately 1.8 L culture medium, at 20 ¿ 2 °C, in an incubator, 16 hours illumination; light intensity of max. 1500 lx. The daphnids were fed at least 5 times per week ad libitum with a mix of unicellular green algae, e.g. Pseudokirchneriella subcapitata and Desmodesmus subspicatus. The algae were cultured at the test facility.

Test type:

static

Water media type:

freshwater

Remarks:

Same as the culture medium

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

None

Hardness:

234 mg CaCO3/L

Test temperature:

19-20.3 °C

pH:

7.58-8.25

Dissolved oxygen:

7.27-8.95 mg/l

Salinity:

Not reported

Conductivity:

545 µS/cm

Nominal and measured concentrations:

Nominal values: control and 100 mg/l
Measured values: below the limit of quantification (LOQ) for both test solutions at both 0 and 48h. LOQ = 0.015 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beakers (4 (ID) x 7 (H) cm), 50 mL capacity, loosely covered with watch glasses
- Aeration: not reported
- 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: Same composition as the culture medium
- Total organic carbon: not reported for the limit test
- Particulate matter: not reported
- Metals: not reported
- Pesticides: not reported
- Chlorine: not reported
- Alkalinity: not reported
- Ca/mg ratio: 234mg CaCO3/L
- Conductivity: 545
- Salinity: not reported
- Culture medium different from test medium: No
- Intervals of water quality measurement: 48h

OTHER TEST CONDITIONS
- Adjustment of pH:
- Photoperiod: 16/8 hours light/dark cycle
- Light intensity: max. 1500 lx

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

VEHICLE CONTROL PERFORMED: no

RANGE-FINDING STUDY
- Test concentrations: 0.500, 5.00 and 50.0 mg/l
- Results used to determine the conditions for the definitive study:
Application, solubility and stability of test item,
No immobilization of daphnids was observed in any concentration after 48h,
Measured concentrations were 0-1% of nominal concentrations at 0 hours and were below the lowest calibration standard after 48h,
TOC was measured and it was determined that due to the fast hydrolysis rate, analytical detection of the parent test item under test conditions is considered to be impossible under test conditions

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

exposure is based on hydrolysis product

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities:
Determination of other adverse, sub-lethal effects (e.g. discolouration, abnormal behavior etc.) was done, but other adverse effects did not occur during the course of the study. The study was performed under static conditions.

- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No
- Effect concentrations exceeding solubility of substance in test medium: The limit loading of 100 mg test item/L was colorless and visually clear throughout the exposure.

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels: yes
- Dose-response test: 24h EC50 = 1.89 mg/l (confidence limits of 1-4mg/l) based on nominal values

Reported statistics and error estimates:

The EL10 / 50 / 100-values after 24 and 48 hours for the test item were empirically derived from the observation data. Since no effects on Daphnia magna were observed in the limit loading of the test item, no calculations were made.
All effect loadings (EL10 / 50 / 100) given were based on the nominal loading of the test item.

REFERENCE ITEM:
An EC50-value was calculated for the reference item by sigmoidal dose-response regression from the best-fit values with the software GraphPad Prism. The respective 95% confidence limits were empirically derived from the observation data as follows: The highest concentration level without any effect (EC0) and the lowest concentration level causing 100% immobilization (EC100) were used as 95% confidence limits.

	Number of immobile Daphnids / Total number of Daphnids					Number of immobile Daphnids / Total number of Daphnids
	24 hours					48 hours
	Replicates					Replicates
Nominal test item loading [mg/l]	1	2	3	4	SUM	1	2	3	4	SUM
100	0/5	0/5	0/5	0/5	0/20	0/5	0/5	0/5	0/5	0/20
Control	0/5	0/5	0/5	0/5	0/20	0/5	0/5	0/5	0/5	0/20

Validity criteria fulfilled:

yes

Conclusions:

Daphnia magna 48h immobilization EC50 >100mg/l of 1,3,5-Tris[3-(trimethoxysilyl)propyl]-1,3,5-triazinane-2,4,6-trione (CAS No. 26115-70-8, EC No. 247-465-8). Test was performed in accordance with OECD 202 (2004).

Description of key information

Short-term toxicity to invertebrates: 48 hr EC₅₀ > 100 mg/L (nominal) (highest concentration tested) 1,3,5-tris[3-(trimethoxysilyl)propyl]-1,3,5-triazinane-2,4,6-trione (CAS 26115-70-8, EC No. 247-465-8) (OECD TG 202). The observations in this study are attributed to the exposure of test organisms to the hydrolysis products in the test system. The EC₅₀ is equivalent to >80 mg/L when expressed in terms of the silanol hydrolysis product, tris[3-(trihydroxysilyl)propyl]-1,3,5-triazinane-2,4,6-trione.

Additional information

A 48 h EC₅₀ value of >100 mg/L (nominal, highest concentration tested) have been determined for the effects of 1,3,5-tris[3-(trimethoxysilyl)propyl]-1,3,5-triazinane-2,4,6-trione (CAS 26115-70-8, EC No. 247-465-8) on mobility of Daphnia magna. In view of the test media preparation method and exposure regime, it is likely that the test organisms were exposed predominantly to the hydrolysis products of the tested substance. The study was supported by LC-MS/MS analysis of the parent substance and concentrations were below the limit of quantification (LOQ = 0.015 mg/L) at 0 and 48 h, which indicated the parent had fully hydrolysed prior to the start of the test. The results may be expressed in terms of concentration of the hydrolysis product, tris[3-(trihydroxysilyl)propyl]-1,3,5-triazinane-2,4,6-trione, by applying a molecular weight correction: (MW of silanol=489.62 / MW of parent=615.86) * [CONCENTRATION OF PARENT=100] = >80 mg/L.