Registration Dossier

Administrative data

Endpoint:
toxicity to microorganisms
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Aug - Nov 1994
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: According to DIN guideline under GLP
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report Date:
1995

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
DIN 38412-8 (Pseudomonas Zellvermehrungshemmtest)
Deviations:
no
Principles of method if other than guideline:
not relevant
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Ethyldienon
- Analytical purity: 89.1%
- Lot/batch No.: 21400404

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
Pseudomonas putida

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
16 h

Results and discussion

Effect concentrations
Duration:
16 h
Dose descriptor:
EC50
Effect conc.:
> 4 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
growth inhibition

Any other information on results incl. tables

The measurements showed that there is no growth inhibition of the bacterial population.

Table 1: Mean values of turbidity (expressed as TE/F) and growth inhibition as a function of the concentration

 Concentration    TE/F ± standard deviation    Growth inhibition  
 [mg/L]    [mean value (16 hours)]    -(%)    
 Control   359  ±   17,8 0
 1 :1000 diluted   355  ±   3,6 1,1
 1 : 1 00 diluted   352  ±   9 1,9
 1 :10 diluted   355  ±   27,5 1,1
 Saturated, not diluted   402  ±   0 -12

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Ethyldienon up to a saturated solution (approximately 4 mg/L) had no inhibitory effect on the growth of Pseudomonas putida. The slight increase of growth at the saturated concentration is not considered to be biologically relevant.
Executive summary:

The purpose of this study was to determine the effects of the test compound Ethyldienon (ZK 28519) on the growth of the bacterium Pseudomonas putida. The study was conducted in agreement with the standard DIN 38412 L8, Mar. 91.

The test substance was incubated in an aqueous solution including nutrients with a bacterial population of Pseudomonas putida for a test duration of approximately 16 hours. The nutrient solution was made up of mainly nitrate, phosphates, carbohydrates, some trace elements and vitamins. A stock solution with a concentration of 1000 mg/L was prepared, stirred for 24 hours and filtered. This filtered stock solution was used for the highest test concentration. For further test concentrations the stock solution was diluted 1 :10, 1:100 and 1 :1000. Additionally, one control without the test substance was used. All test solutions including the control were incubated in triplicate. Furthermore, for each test concentration one test vessel was incubated without addition of the inoculum in order to analyse the inherent turbidity of the test compound. The concentration of the saturated, filtered solution was analysed with a TOC-analyser and subsequent calculation based on the structural formula.

As a parameter for the growth of the bacterial population, the turbidity of the test and control solutions was analysed photometrically at a wave-Iength of 436 nm.

The measurements showed that there is no growth inhibition of the bacterial population. On the contrary, there is a slight growth increase at the highest test concentration in comparison with the control group.