Ethylenebis(oxyethylene) bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate]

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:

1988-11-15 to 1988-11-23

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non-GLP guideline study (OECD 209). Deviations to the updated OECD Guideline (adopted 2010) The coefficient of analysis of the control was not reported and a reduced number of replicates in the treatment groups were used.

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Version / remarks:

reliability scoring based on 1984 guideline

Deviations:

yes

Remarks:

settled sludge was used, and one concentration was tested due to the low toxicity

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

Twice 21.1 mg of the test substance were weighed and added to the test medium. The volume was adjusted to 200 mL with bidistilled water and aerated for 3 hours. The substance was not dissolved.

Test organisms (species):

activated sludge, domestic

Details on inoculum:

Activated sludge collected from the sewage treatment plant of CH - 4153 Reinach on 14/11/88. The preparation was carried out according to the method described in the guideline. The sludge was separated from the aqueous layer by settling instead of centrifugation. The sludge concentrations in the test bottles was 1.7 g/l.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

20°C ± 2°C

Nominal and measured concentrations:

Nominal - 105.5 mg/l

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 ml BOD flasks with gas inlet
- # of vessels per control: 2
- # of vessels per concentration: 2
- # of vessels per reference substance concentration: 1 per conc for a total of 3

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol

Duration:

3 h

Dose descriptor:

other: IC20

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

3 h

Dose descriptor:

IC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

3 h

Dose descriptor:

other: IC80

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Results with reference substance (positive control):

IC50 = 9 mg/L

Reported statistics and error estimates:

None (values determined graphically)

Description of key information

The inhibition of the degradation activity of activated sludge is not anticipated when introduced in appropriate low concentrations. 

Additional information

A respiration inhibition test according to OECD guideline 209 was conducted (CIBA-GEIGY 1988). The IC20, IC50 and IC80 values for respiration inhibition were greater than 100 mg/L .