3-[(2,2-Dimethyl-1,2-azasilolidin-1-yl)(dimethyl)silyl]-1-propanamine

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD Guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

CAS No.:388606-32-4
Batch No.: YH00701
Chemical name: 1-[(3-Aminopropyl)dimethylsilyl]-2,2dimethyl-1-aza-2-silacyclopentan
Purpose: industrial chemical
Colour: colourless to yellowish
Physical state: liquid
Storage: at room temperature, protected from light and humidity
Safety precautions: Routine hygienic procedures were sufficient
to assure personnel health and safety

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

The test item is instable in water since hydrolysis will occur. Therefore adequate amounts of the test item were directly weighed into each test flask. One test solution with a final volume of 500 mL was tested per treatment in a glass flask (>500 mL). Samples were prepared in about I5-minute intervals.

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Activated sludge, micro organisms from a domestic waste water treatment plant supplied by the sewage plant Darmstadt, Germany
The activated sludge was washed by centrifugation and the supematant liquid phase was decanted. The solid material was re-suspended in tap water and again centrifuged. The latter procedure was repeated twice. The washed sludge was resuspended in tap water and sewage feed (50 mL per L,)
was added. The sludge was kept at room temperature under continuous aeration until use for one day. Immediately before use, the dry weight of the activated sludge was determined, and diluted to 2 g/L with tap water. The pH of the activated sludge was 7.3 and therefore no adjustment was necessary.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

3 h

Post exposure observation period:

not reported

Test conditions

Hardness:

not reported

Test temperature:

18 - 23 °C

pH:

7.3

Dissolved oxygen:

8.5 - 4.1 mg/L.

Salinity:

not applicable

Nominal and measured concentrations:

10, 32, 100, 320, 1000 mg/l

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol

Results and discussion

Effect concentrations

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

338.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Details on results:

In comparison to the inoculum controls the respiration rate of the activated sludge was slightly inhibited by 1.7 %, 8.5 % and 5.1 % at the three lowest nominal test concentrations of 10, 32 and 100 mg/L, respectively. At the next higher concentrations of nominal 320 and 1000 mg/L, the respiration rates were inhibited by 45.8 % and 96.6 %, respectively. Concentrations exceeding 1000 mg/L nominal were not tested.
The 3-hour EC20 was calculated by Probit analysis to be 195.8 mg/L. The 3-hour EC50 was calculated by Probit analysis to be 338.9 mg/L nominal. No ECso was calculated.

Results with reference substance (positive control):

The 3-hour EC50 for the positive control 3,5-Dichlorophenol, which was tested in the same way as the test item, was found to be 16.4 mg/L and is within the range of 5 - 30 mg/L recommended by the test guidelines; thus, confirming suitability of the activated sludge.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 3-hour EC20 was calculated by Probit analysis to be 195.8 mg/L. The 3-hour EC50 was calculated by Probit analysis to be 338.9 mg/L nominal. No EC80 was calculated.

Executive summary:

The influence of the test item on the activity of activated sludge was evaluated by measuring the respiration rate under defined conditions of the OECD guideline 209. The respiration rate (oxygen consumption) of an aerobic activated sludge fed with a standard amount of synthetic sewage was measured in the presence of various concentrations of the test item after an incubation period of 3 hours. Concentrations of 10,32, 100,320 and 1000 mg test item, 3.2, 10 and 32 mg 3,5-Dichlorophenol/L (control) and two inoculum controls were tested. In comparison to the inoculum controls the respiration rate of the

activated sludge was slightly inhibited by 1.7 %, 8.5 % and 5.1 % at the three lowest nominal test concentrations of 10, 32 and

100 mg/L, respectively. At the next higher concentrations of nominal 320 and 1000 mg/L, the respiration rates were inhibited by

45.8 % and 96.6 %, respectively. Concentrations exceeding 1000 mg/L nominal were not tested. The 3-hour EC20 was calculated by Probit analysis to be 195.8 mg/L. The 3-hour EC50 was calculated by Probit analysis to be 338.9 mg/L nominal. No EC80 was calculated. The 3-hour EC50 for the positive control 3,5-Dichlorophenol, which was tested in the same way as the test item, was found to be 16.4 mg/L and is within the range of 5 - 30 mg/L recommended by the test guidelines; thus, confirming suitability of the activated sludge.

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