A mixture of cis- and trans-cyclohexadec-8-en-1-one

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:

1998-06-22 to 1998-07-3

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

other: According to Commission Directive 88/302/EEC, Official Journal of the EC L133, Part C: Biodegradability: Test for inhibition of oxygen consumption

Version / remarks:

(correspondings for the most part to the test method OECD 209)

GLP compliance:

yes

Analytical monitoring:

no

Remarks:

The study was carried out with nominal weights. The test concentrations were not confirmed by chemical analysis.

Vehicle:

no

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Laboratory culture: No
- Name and location of sewage treatment plant where inoculum was collected: Wupper area water authority.
- Pretreatment: No

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

19.8 - 20.2 °C

pH:

7.6-7.7

Dissolved oxygen:

Control:
Start: 6.0-6.5 mg O2/L; End: 2.6 mg O2/L;
Test solution:
Start: 4.2-5.6 mg O2/L; End: 2.6-2.9 mg O2/L;
Physiochemical oxygen consumpation conctrol (10000 mg/L):
Start: 7.4 mg O2/L; End: 7.4 mg O2/L;

Nominal and measured concentrations:

Nominal concentrations: 100-1000-10000 mg/L with a test concentration separation factor of 10

Details on test conditions:

Not reported in details

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol

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

Details on results:

See below

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Relevant effect levels: 5-20 mg/L (12.7-83.9% inhibition)

 

Inhibition of the test item to the respiration of microorganisms:

Test concentration [mg/L]	Respiratory rate test substance [mg/L*h]	Phys.chem. O2-consumption [mg/L*h]	Respiratory rate -phys. chem.  Phys.chem. O2-consumption [mg/L*h]	Inhibition [%]
100	33.6	0	33.6	0
1000	34.5	0	34.5	0
10000	32.0	0	32.0	0
Control-1	29.1	-	-	-
Control-2	29.3	-	-	-
Control-mean	29.2	-	-	-

Phys.chem. O2-consumption is carried out to determine if any oxygen is consumed by chemical reactivity of the test substance.

 

Validity criteria fulfilled:

yes

Conclusions:

The EC50 (3h) of the test item to the respiration of microorganisms was determined to be above 10000 mg/L.

Executive summary:

The inhibition effect of the test item to the respiration of microorganisms was tested according to Commission Directive 88/302/EEC, Official Journal of the EC L133 part C (similar to OECD 209) and GLP. Three concentrations (100-10000 mg/L) with a separation factor of 10 were tested. The EC50 (3h) of the test item to the respiration of microorganisms was determined to be above 10000 mg/L. 

Description of key information

A study on the inhibition effect of the test item to the respiration of microorganisms was conducted according to Commission Directive 88/302/EEC, Official Journal of the EC L133 part C (similar to OECD 209) and GLP. Three concentrations (100-10000 mg/L) with a separation factor of 10 were tested. The EC50 (3h) of the test item to the respiration of microorganisms was determined to be above 10000 mg/L. 

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

10 000 mg/L