Bis(triethoxysilylpropyl)amine

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02 - 22 Nov 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

ISO 10253 (Water quality - Marine Algal Growth Inhibition Test with Skeletonema costatum and Phaeodactylum tricornutum)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: The dissolved organic carbon (DOC) concentration was determined in nominal concentrations of 30, 147.4 and 426 mg/L at 0, 24, 48 and 72 h during the test in media that did not contain algae but was otherwise kept under test conditions. The mean concentrations in the three media were used to estimate the mean concentrations in all the media by linear interpolation.
- Sampling method: not reported
- Sample storage conditions before analysis: Retained samples were stored at -20 °C

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test substance was dissolved in algal growth medium to produce a stock solution with a nominal concentration of 473.4 mg/L. The solution was stirred for 1 hour and then diluted with algal growth medium to produce the test concentrations.

Test organisms (species):

Phaeodactylum tricornutum

Details on test organisms:

TEST ORGANISM
- Strain: 1090-1a SAG obtained from the University Institute of Plant Physiology, Göttingen, Germany
- Source (laboratory, culture collection): laboratory culture
- Age of inoculum (at test initiation): 3 days

Test type:

static

Water media type:

saltwater

Limit test:

no

Total exposure duration:

72 h

Hardness:

not reported

Test temperature:

19.8 - 21.4 °C

pH:

8.0 - 8.8 at start of test
8.0 - 8.2 at end of test

Dissolved oxygen:

not reported

Salinity:

34 ppt

Nominal and measured concentrations:

Nominal concentrations: 0 (Control), 30, 51, 86.7, 147.4, 250.6 and 426 mg/L
Calculated effective concentrations: 0 (Control), 42, 58, 87, 135, 217 and 356 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks
- Type: closed with pulp bung
- Material, size, fill volume: 100 ml containing 50 ml of medium
- Aeration: none
- Initial cells density: 10000
- Control end cells density: 550000
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Culture medium different from test medium: no
- Intervals of water quality measurement: pH determined at start and end of test

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: no
- Photoperiod: continuous
- Light intensity and quality: 8100+/-8% Lux (RSD)
- Salinity (for marine algae): 34 ppt

EFFECT PARAMETERS MEASURED: cell concentrations at the start of the test and after 24, 48 and 72 hours incubation.

- Determination of cell concentrations: counting chamber and microscope

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.7
- Range finding study: yes
- Test concentrations: concentrations tested and results not reported

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

125 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 106.9-146.1 mg/L

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

118.3 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 104.7-134.4 mg/L

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

68 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 42.1-84.5 mg/L

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

71.1 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 49.4-84.5 mg/L

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

51 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

58.5 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

51 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

58.5 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

91.23 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 81.9-101.9 mg/L

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

90.9 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 82.3-101.5 mg/L

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

56.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 39.9-65.9 mg/L

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

61.8 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 44.5-71 mg/L

Details on results:

- Exponential growth in the control: yes
- Any stimulation of growth found in any treatment: no

Results with reference substance (positive control):

- Results with reference substance valid?: yes
- 72-h EC50 for growth rate: 25 mg/L

Reported statistics and error estimates:

The area under the growth curve (biomass) and growth rate parameters were calculated from the cell concentration data in accordance with the description of the test method.

The EC50 and NOEC values were calculated using the Statistics Software ToxRat® Standard Version 2.09. The software calculates ECx values by Probit analysis using linear, maximum liklihood regression. NOECs were calcultaed using Dunnett's multipley-test procedure.

Table 1. Test results

Nominal test substance concentration (mg/L)	Mean cell concentration at start of test (cells/mL)	Mean cell concentration after 24 h (cells/mL)	Mean cell concentration after 48 hours (cells/mL)	Mean cell concentration after 72 hours (cells/mL)
0 (control)	10000	30000	160000	550000
30	10000	20000	150000	570000
51	10000	30000	160000	550000
86.7	10000	40000	120000	190000
147.4	10000	20000	40000	50000
250.6	10000	10000	0	0
426.0	10000	10000	0	0

Table 2. Results of analysis of test media - samples analysed immediately after collection

Nominal test substance concentration (mg/L)	Nominal TOC concentration (mg/L)	Measured DOC concentration at start of test (mg/L)*	Measured DOC concentration after 24 hours (mg/L)*	Measured DOC concentration after 48 hours (mg/L)*	Measured DOC concentration after 72 hours (mg/L)*
0 (Control)	0	20.0	19.0	14.5	12.5
30.0	12.5	18.6	20.4	29.7	20.0
147.4	61.5	70.0	34.3	65.3	28.4
426.0	177.6	198.2	142.4	146.2	114.2

*corrected for Control DOC

Table 3. Results of analysis of test media - samples analysed following 20 days storage under refridgeration

Nominal test substance concentration (mg/L)	Nominal TOC concentration (mg/L)	Measured DOC concentration at start of test (mg/L)	Measured DOC concentration after 24 hours (mg/L)	Measured DOC concentration after 48 hours (mg/L)	Measured DOC concentration after 72 hours (mg/L)
0 (Control)	0	13.0	14.0	6.4	7.0
30.0	12.5	no data	no data	no data	3.4
147.4	61.5	34.8	15.9	18.9	15.3
426.0	177.6	123.0	75.1	94.9	67.9

The results of the analyses performed immediately after collection of the samples were used as the basis for determining the exposure concentrations that were used as the basis for calculating the effective concentrations.

Validity criteria fulfilled:

yes

Conclusions:

A 72-h EC50 value of 125 mg/L based on nominal concentration (118.3 mg/L based on estimated concentration from DOC measurement) has been determined in the study testing the effect of the test substance on the growth rate of the marine alga Phaeodactylus tricornutum. The 72-h EC10 determined for the same endpoint was 68 mg/L (71.1 mg/L based on estimated concentration from DOC measurement).

Description of key information

ErC50 (72 h) = 125 mg/L (nominal, marine alga Phaeodactylum tricornutum, ISO 10235)

ErC10 (72 h) = 68 mg/L (nominal, marine alga Phaeodactylum tricornutum, ISO 10235)

Key value for chemical safety assessment

EC50 for marine water algae:

125 mg/L

EC10 or NOEC for marine water algae:

68 mg/L

Additional information

Experimental data are available testing the acute toxicity of 3-(triethoxysilyl)-N-[3-(triethoxysilyl)propyl]-1-propanamine (CAS No. 13497-18-2) towards algae. The study was performed according to the ISO guideline 10235 and GLP standards (2004). The salt water algae Phaeodactylum tricornutum was used for testing and was exposed for 72 h to the nominal test item concentrations of 0 (Control), 30, 51, 86.7, 147.4, 250.6 and 426 mg/L. The study showed effects on the growth rate of the algae resulting into a 72-h ErC50 value of 125 mg/L and an 72-h ErC10 value of 68 mg/L (both nominal).