Reaction mass of benzyl 2-ethylhexyl adipate and bis(2-ethylhexyl) adipate and dibenzyl adipate

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:

1989

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

no

Qualifier:

according to guideline

Guideline:

ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

purity not specified
Molecular formula: C21H32O4
Molecular weight: 349 g/mol

Analytical monitoring:

no

Test organisms (species):

activated sludge

Details on inoculum:

- Initial biomass concentration: 6.0 g/L (dry weight)
- laboratory scale sewage treatment plant treating synthetic sewage (OECD 209)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

21.4°C

pH:

7.9

Dissolved oxygen:

O2 - Start: 2.9 - 7.9 mg
O2 - End: 2.0 - 6.1 mg

Nominal and measured concentrations:

nominal: 100, 1000 and 10000 mg/L

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorphenole

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Details on results:

The concentrations of the test item and reference compound were not confirmed by analytical methods, but instead based on nominal concentrations.

Results with reference substance (positive control):

EC50 of the reference compound 3.5-Dichlorophenol is < 20 mglL

Validity criteria fulfilled:

yes

Remarks:

on the basic of graphic evaluation; The EC50 for 3,5-DCP was < 20 mg/L and between the prescribed limits of 5 and 30 mg/L.

Conclusions:

A test with activated sludge with a duration fo 3 hours was performed according to the OECD Guideline 209 which is equivalent to ISO 8192 (Test for Inhibition of Oxygen Consumption by Activated Sludge). For 'Reaction mass of benzyl 2-ethylhexyl adipate and bis(2-ethylhexyl) adipate and dibenzyl adipate' an EC50 of > 10000 mg/L was observed.

Executive summary:

A test with activated sludge with a duration for 3 hours was performed according to the OECD Guideline 209 which is equivalent to ISO 8192 (Test for Inhibition of Oxygen Consumption by Activated Sludge).

The purpose of this test was to provide a rapid screening method whereby substances which may adversely affect aerobic microbial treatment plants can be identified, and to indicate suitable non-inhibitory concentrations of test items to be used in biodegradability tests. The method assessed the effect of a test item on microorganisms by measuring the respiration rate under defined conditions in the presence of different concentrations of the test item. With 'Reaction mass of benzyl 2-ethylhexyl adipate and bis(2-ethylhexyl) adipate and dibenzyl adipate' no respiration inhibition was observed at 100, 1000 and 10000 mg/L. Therefore the EC50 is higher than 10000 mg/L.

Description of key information

A test with activated sludge with a duration fo 3 hours was performed. For 'Reaction mass of benzyl 2-ethylhexyl adipate and bis(2-ethylhexyl) adipate and dibenzyl adipate' an EC50 of > 10000 mg/L was observed.

Key value for chemical safety assessment

EC50 for microorganisms:

10 000 mg/L

Additional information

A test with activated sludge with a duration for 3 hours was performed according to the OECD Guideline 209 which is equivalent to ISO 8192 (Test for Inhibition of Oxygen Consumption by Activated Sludge).

The purpose of this test was to provide a rapid screening method whereby substances which may adversely affect aerobic microbial treatment plants can be identified, and to indicate suitable non-inhibitory concentrations of test items to be used in biodegradability tests. The method assessed the effect of a test item on microorganisms by measuring the respiration rate under defined conditions in the presence of different concentrations of the test item. With 'Reaction mass of benzyl 2-ethylhexyl adipate and bis(2-ethylhexyl) adipate and dibenzyl adipate' no respiration inhibition was observed at 100, 1000 and 10000 mg/L. Therefore the EC50 is higher than 10000 mg/L.