Benzyl benzoate

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:

21/02/1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Remarks:

This study was carried out according to ISO 8192 (equivalent to OECD 209) and to GLP standards. However, some information on test parameters was not included in the report. As such, the study is considered to be Klimisch 2.

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

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

yes

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not applicable

Analytical monitoring:

no

Details on sampling:

Not applicable

Vehicle:

no

Details on test solutions:

Test solutions were created from a directly weighed sample of the test item. Test concentrations were 1000, 1800, 3200, 5600 and 10000 mg/l

Test organisms (species):

activated sludge

Details on inoculum:

The activated sludge samples were taken from a laboratory sewage plant (OECD) on the 14/02/1992.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

3 h

Hardness:

No information provided

Test temperature:

No information provided

pH:

No information provided

Dissolved oxygen:

No information provided

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal test concentrations were 1000, 1800, 3200, 5600 and 10000 mg/l.

Details on test conditions:

Test conditions were in line with SOP 3.005, 1.004, 1.006, 1.007

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenole

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 EC50 was found to be >10000 mg/l based on respiration rate inhibition.

Results with reference substance (positive control):

The test was validated with a reference substance.

Reported statistics and error estimates:

No information provided

Table 1: Measured respiration rate and inhibition results

Test concentration (mg/l)	Respiration rate (mg/l.h)	Inhibition (%)
1000	26.4	18.3
1800	22.8	29.4
3200	21.0	35.0
5600	20.0	33.1
10000	17.0	47.4

Validity criteria fulfilled:

not specified

Conclusions:

The EC50 was determined to be >10000 mg/l

Executive summary:

A 3 hour respiration inhibition test was carried out on activated sludge according to ISO 8192. Nominal test concentrations of benzyl benzoate were 1000, 1800, 3200, 5600 and 10000 mg/l. The EC50 was found to be >10000 mg/l.

Description of key information

The 3-hour EC50 was determined to be >1000 mg/L.

Key value for chemical safety assessment

EC50 for microorganisms:

10 000 mg/L

Additional information

A 3 hour respiration inhibition test was carried out on activated sludge according to ISO 8192. Nominal test concentrations of benzyl benzoate were 1000, 1800, 3200, 5600 and 10000 mg/l. The EC50 was found to be >10000 mg/l.