N-(3-{1,1,1,5,5,5-hexamethyl-3-[(trimethylsilyl)oxy]trisiloxan-3-yl}propyl)prop-2-enamide

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-10-2 to 2010-10-08

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study according to international Guidelines, fully GLP monitored, no deviations

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

N-(3-{1,1,1,5,5,5-hexamethyl-3-[(trimethylsilyl)oxy]trisiloxan-3-yl}propyl)prop-2-enamide

EC Number:

700-253-3

Cas Number:

115258-10-1

Molecular formula:

C15H37NO4Si4

IUPAC Name:

N-(3-{1,1,1,5,5,5-hexamethyl-3-[(trimethylsilyl)oxy]trisiloxan-3-yl}propyl)prop-2-enamide

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 29, 9.2, 2.9, 0.92 and 0.29 µg test item/L
- Sampling method: no data
- Sample storage conditions before analysis: The freshly prepared test media were stored in a freezer (<= -10°C), protected from light until analysis was performed, whereas the aged test media were measured directly on the day of sampling

Test solutions

Vehicle:

yes

Details on test solutions:

REPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method:acc. to OECD 23 with solvent
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Dimethylformamide
- Concentration of vehicle in test medium (stock solution and final test solution): stock soluition: 290 mg/L
- Evidence of undissolved material (e.g. precipitate, surface film, etc): no

Test organisms

Test organisms (species):

Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchneriella subcapitata
- Strain:No. 61.81 SAG
- Source (laboratory, culture collection): SAG
- Age of inoculum (at test initiation):
- Method of cultivation: continous standard culture in exponontial growth

ACCLIMATION
- Acclimation period: not applicable
- Culturing media and conditions (same as test or not): no data
- Any deformed or abnormal cells observed: no

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

no

Test conditions

Hardness:

OECD medium
hardness (calculated): 0,24 mmol/L ^= 24 mg/L as CaO)

Test temperature:

23-24

pH:

8.0 (start); 8.9 - 9.5 (test end)

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmayer flask
- Type (delete if not applicable): open but covered
- Material, size, headspace, fill volume: glass, 50 ml
- Initial cells density: 5000 cells/mL
- Control end cells density: 72.745E+5

- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6
- No. of vessels per vehicle control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes
- Detailed composition if non-standard medium was used: not applicable

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: OECD water
- Culture medium different from test medium: no data
- Intervals of water quality measurement: no data

OTHER TEST CONDITIONS
- Sterile test conditions: no data
- Adjustment of pH: no data
- Photoperiod: 24/0
- Light intensity and quality:6035 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: spectrophotometer
- Chlorophyll measurement: no


TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3,15
- Justification for using less concentrations than requested by guideline:
- Range finding study yes
- Test concentrations: 0.29, 0.92, 2.9, 9.2, 29 µg/L (each in 100 µL DMF/L)
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

not specified

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 29 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 29 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 29 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 4

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 29 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 5

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 29 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 6

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 29 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): no
- Unusual cell shape: no
- Colour differences: no data
- Flocculation: no
- Adherence to test vessels: not reported
- Aggregation of algal cells: not reported
- Other:
- Any stimulation of growth found in any treatment: no
- 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: yes

Reported statistics and error estimates:

not applicable, due to no observed effect in the tests

Any other information on results incl. tables

I Biological results

Parameter (0 - 72 h)	Growth rate [µg test item/L]	Yield [µg test item/L]
72-hour EC50	> 29	> 29
95 % conf. limits	n.d.	n.d.
72-hour EC10	> 29	> 29
95 % conf. limits	n.d.	n.d.
72-hour NOEC	≥ 29	≥ 29
72-hour LOEC	> 29	> 29
n.d. = not determinable Values refer to nominal test concentrations

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Under test conditions no inhibition of growth, rate and yield could be observed. The test item is regarded as not toxic up to the water solibility of 29 µg/L to the tested green algae Pseudokirchneriella subcapitata.

Executive summary:

The influence of N-[3-tris(trimethylsilyloxy) silylpropyl]prop-2-enamide on the growth of the freshwater green algae Pseudokirchneriella subcapitata was assessed in a static dose-response test. The 72-hour NOEC was determined to be at least 29 µg test item/L. The NOEC might even be higher than this concentration, but concentrations in excess of the limit of solubility have not been tested according to the recommendations of the test guidelines. The 72-hour LOEC and the 72-hour EC₅₀were clearly higher than 29 µg test item/L. These values could not be quantified due to the absence of toxicity of N-[3-tris(trimethylsilyloxy) silylpropyl]prop-2-enamide up to the limit of solubility.

Under test conditions no inhibition of the test item to the tested algae were detectable.