9-[2-(2-methoxyethoxy)ethoxy]-9-[3-(oxiranylmethoxy)propyl]-2,5,8,10,13,16-hexaoxa-9-silaheptadecane

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29 February 1996 to 1 March 1996

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

9-[2-(2-methoxyethoxy)ethoxy]-9-[3(oxiranylmethoxy)propyl]- 2,5,8,10,13,16-hexaoxa-9-silaheptadecane was investigated for its ability to inhibit the cell multiplication of the bacteria species Pseudomonas putida according to DIN 38412 Part L 8 (March 1991) and NEN-EN-ISO 10712 (1996).the information is reported to an appropriate standard but it is not clear if the study was conducted in accordance with Good Laboratory Practice.

Qualifier:

according to guideline

Guideline:

DIN 38412-8 (Pseudomonas Zellvermehrungshemmtest)

Deviations:

no

GLP compliance:

not specified

Specific details on test material used for the study:

Batch number: 84246753
Expiry date: 14 August 1997

Analytical monitoring:

no

Details on sampling:

Not applicable

Vehicle:

no

Details on test solutions:

Since the test substance was soluble in water, a stock solution of 12,500 mg per litre in Milli-Q water (tap water purified by reverse osmosis and subsequently passed over activated carbon and ion-exchange cartridges (Millipore Corp., Bedford, Mass., USA)) was prepared. The solution was
thoroughly mixed to accelerate the dissolving of the test substance. No additives were used. The pH of the stock solution was 7.7.
Because of possible hydrolysis of the test substance, the test was started directly after preparation of the stock solution.

Test organisms (species):

Pseudomonas putida

Details on inoculum:

Test system Pseudomonas putida.
Strain MIGULA, Berlin 33/2 (DSM 50026).
Source BGA, Berlin, Germany.
Rationale Recognized by international guidelines.
Stock cultures of the bacteria are stored in liquid nitrogen (-196°C)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

16 h

Remarks on exposure duration:

Not applicable

Post exposure observation period:

Not applicable

Test temperature:

23 + 1°C

Nominal and measured concentrations:

Nominal test concentrations were 313, 625, 1250, 2500, 5000 and 10000 mg/L

Details on test conditions:

Vessels 100 ml Erlenmeyer flasks
Incubation temperature 23 + 1°C
Incubation time
- preliminary suspension cultures 6 + 1 hours
- exposure 18 + 2 hours

Nutrient medium: 18 g of agar dissolved in water, plus 50 ml of solution I, 125 ml of solution III and 100 ml of solution IV, made up to one litre with water.

Reference substance (positive control):

yes

Remarks:

3,5 - Dichlorophenol (97 %, Aldrich).

Key result

Duration:

16 h

Dose descriptor:

EC10

Effect conc.:

> 10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Details on results:

After incubation extinction values were measured and the cell multiplication inhibition for each test concentration was determined. Since no significant (significant: >10%) inhibition of cell multiplication was observed the toxicity threshold value of 9-[2-(2-methoxyethoxy)ethoxy]-9-[3(oxiranylmethoxy)propyl]- 2,5,8,10,13,16-hexaoxa-9-silaheptadecane for Pseudomonas putida was >10,000 mg/1.

Results with reference substance (positive control):

The EC50 value of 3,5-dichlorophenol determined for Pseudomonas putida as calculated by linear regression (Y = 5.4824 X -63.5703) was 21 mg/l. The inoculum used in the control batch was multiplied by a factor 71 within the test period. With respect to the accepted range of 10-30 mg/1 for the EC50 of the reference substance and the multiplication factor of the bacteria within the test being over 60, it was concluded that the test conditions were optimal and the results obtained were valid.

Validity criteria fulfilled:

yes

Conclusions:

No toxicity was observed. Based on the results of the test presently performed, the toxicity threshold value (EC10) was >10,000 mg/1.

Executive summary:

9-[2-(2-methoxyethoxy)ethoxy]-9-[3(oxiranylmethoxy)propyl]- 2,5,8,10,13,16-hexaoxa-9-silaheptadecanewas investigated for its ability to inhibit the cell multiplication of the bacteria species Pseudomonas putida according to DIN 38412 Part L 8 (March 1991) and NEN-EN-ISO 10712 (1996).

Suspensions of Pseudomonas putida were exposed to concentrations of the test substance ranging from 312.5 to 10,000 mg/l. After incubation the extinction values of the bacterial cell suspensions were measured. No toxicity was observed. Based on the results of the test presently performed, the toxicity threshold value (EC10) was >10,000 mg/1. The "Bewertungszahl" (Assessment'figure or value for bacterial toxicity) is therefore < 1.9 (Bewertung wassergefährdender Stoffe, 1989).

Description of key information

9-[2-(2-methoxyethoxy)ethoxy]-9-[3(oxiranylmethoxy)propyl]- 2,5,8,10,13,16-hexaoxa-9-silaheptadecane was investigated for its ability to inhibit the cell multiplication of the bacteria species Pseudomonas putida according to DIN 38412 Part L 8 (March 1991) and NEN-EN-ISO 10712 (1996). Suspensions of Pseudomonas putida were exposed to concentrations of the test substance ranging from 312.5 to 10,000 mg/l. After incubation the extinction values of the bacterial cell suspensions were measured. No toxicity was observed. Based on the results of the test presently performed, the toxicity threshold value (EC10) was >10,000 mg/1. The "Bewertungszahl" (Assessment'figure or value for bacterial toxicity) is therefore < 1.9 (Bewertung wassergefährdender Stoffe, 1989).

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

10 000 mg/L