Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
11.04.1990
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline study: deficiecies in documentation

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1991
Report date:
1991

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other: DIN 38412 part 27
Deviations:
no
GLP compliance:
not specified

Test material

Constituent 1
Chemical structure
Reference substance name:
Zinc diricinoleate
EC Number:
235-911-4
EC Name:
Zinc diricinoleate
Cas Number:
13040-19-2
Molecular formula:
C18H34O3.1/2Zn
IUPAC Name:
zinc bis(12-hydroxyoctadec-9-enoate)

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
yes
Details on test solutions:
A stock solution with a concentration of 500 mg test substance/L was prepared under use of an untoxic emulsifier. Further concentrations (250, 125, 63 mg/L) were prepared by dilution. The dilution water was a synthetic drinking water according to the test method applied. It was prepared daily and aerated until consumption.

Test organisms

Test organisms (species):
Pseudomonas putida

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
60 min

Test conditions

Hardness:
no information
Test temperature:
20 +/- 1 °C
pH:
no information
Dissolved oxygen:
no information
Salinity:
no information
Nominal and measured concentrations:
Nominal test concentratrions: 500, 250, 125, 63 mg test substance/L
Details on test conditions:
TEST SYSTEM
- Test vessel: System made by Behr. It consists of an oxygen meter WTW OXI 537, an oxygen electrode EO 96 with temperature compensation. The respiration rate is measured in a cell with stirrer and is recorded by a compensation recorder.
- Aeration: The tests are incubated to 20 +/- 1 °C one hour of aeration.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: synthetic drinking water according to the test method used

TEST CONCENTRATIONS
- Test concentrations: 500, 250, 125, 63 mg/L
Reference substance (positive control):
no

Results and discussion

Effect concentrations
Duration:
60 min
Dose descriptor:
EC10
Effect conc.:
60 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate

Any other information on results incl. tables

During the test the following respiration rates were measured and used for calculting the inhibition.

 Concentration (mg/L)  Respiration rate (mg/L/min)  Inhibition (%)
 Control 1 36   
 Control 2  34  
 500  16  54
 250  22  37
 125  28  20
 63  30  14

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Executive summary:

An acute bacteria toxicity test according to DIN 38412 part 27 was carried out with zinc diricinoleate. Pseudomonas putida was exposed to nominal test concentrations of 63, 125, 250 and 500 mg/L. The EC50 of zinc diricinoleate amounts to 460 mg/L, the EC10 amounts to 60 mg/L.