Benzyl acetate

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:

From 18 to 20 February 1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other:

Remarks:

The study was performed acording to a recognised guideline and was GLP compliant.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Qualifier:

according to guideline

Guideline:

other: ISO 8192-1986 requirement (E)

GLP compliance:

yes

Analytical monitoring:

no

Details on sampling:

Not applicable

Test organisms (species):

activated sludge

Details on inoculum:

The activated sludge used was obtained from the laboratory sewage treatment plant. It was not pre-treated. The concentration of the inoculum was 6 g/L TS. Autooxidation was 10000 mg/L.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Post exposure observation period:

Not applicable

Hardness:

Not applicable

Test temperature:

Not reported

pH:

Not reported

Dissolved oxygen:

Not applicable

Salinity:

Not applicable

Nominal and measured concentrations:

The following nominal test concentrations were used: 180, 320, 560, 1000, 1800 mg/L.

Details on test conditions:

A defined amount of activated sludge was mixed with synthetic Nährlösug the respiration rate was measured. This respiration rate was compared with those measured in test preparations with different concentrations of test substance.

Reference substance (positive control):

yes

Remarks:

3, 5 - dichlorophenol

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

855 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):

No results stated.

Reported statistics and error estimates:

Not reported.

Table 1: Respiration and Inhibition of Benzylacetate

Test Concentration (mg/L)	Respiration Rate (mg/L.h)	% Inhibition
180	33.0	0.0
320	32.0	0.9
560	25.5	21.1
1000	11.0	65.9
1800	3.0	90.7

The test concentrations result from the use amounts of audit and were not verified analytically.

The EC-values can be found in the graph given below.

Validity criteria fulfilled:

yes

Conclusions:

A study was performed to assess the effects of benzyl acetate on microorganisms. The method followed that described in the ISO 8192-1986 requirement E guideline (equivalent to OECD 209). The EC50 value was 855 mg/L.

Executive summary:

A study was performed to assess the effects of benzyl acetate on microorganisms. The method followed that described in the ISO 8192-1986 requirement E guideline (equivalent to OECD 209).

Nominal exposure concentrations were 180, 320, 560, 1000 and 1800 mg/L.  Respiration rates were 33.0, 32.0, 25.5, 11.0 and 3.0 mg/L.h and the % inhibition values were 0, 0.9, 21.1, 65.9 and 90.7%. The EC₅₀ was 855 mg/L.

Description of key information

A study was performed to assess the effects of benzyl acetate on microorganisms. The method followed that described in the ISO 8192-1986 requirement E guideline (equivalent to OECD 209) (Muller, 1994). 
Nominal exposure concentrations were 180, 320, 560, 1000 and 1800 mg/L. Respiration rates were 33.0, 32.0, 25.5, 11.0 and 3.0 mg/L.h and the % inhibition values were 0, 0.9, 21.1, 65.9 and 90.7%.  The EC50 was 855 mg/L. 

Key value for chemical safety assessment

EC50 for microorganisms:

855 mg/L

Additional information

A study was performed to assess the effects of benzyl acetate on microorganisms. The method followed that described in the ISO 8192-1986 requirement E guideline (equivalent to OECD 209). The EC50 value was 855 mg/L (Muller, 1994).