Registration Dossier

Administrative data

Endpoint:
toxicity to microorganisms
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1988-06-15 to 1988-06-16
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Report generated from archived laboratory manuscripts. No GLP. No recent guideline followed. Procedure following proposal of ETAD-Ecological sub-committee: "Determination of damage to effluent bacteria by the fermentationtube method (1976)."

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report date:
1988

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
ETAD Fermentation Tube Method
Deviations:
not specified
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
not specified

Test solutions

Details on test solutions:
- Stock solution: Saturated solution, prepared by suspending 40 mg/L in deionized water, adjusting the pH from 5.2 to 7.2, stirring over 24 hrs at room temperature and filtrating the batch through a folded paper filter.
- Analysis of the stock solution: 8 mg DOC /L (dissolved organic carbon)
- Concentration of the stock solution: 18.1 mg/L (calculated from the DOC)

Test organisms

Test organisms (species):
sewage, domestic
Details on inoculum:
- As inoculum sewage sludge from a domestic sewage treatment plant was used

Study design

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

Test conditions

Details on test conditions:
- Temperature during incuabtion: 37 °C

- Blank controls were used for determination of the 100% values (basis of the calculations), but the use of further controls was not mentioned in the laboratory manuscript.

Results and discussion

Effect concentrationsopen allclose all
Duration:
24 h
Dose descriptor:
EC0
Effect conc.:
2.3 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: gas production inhibition
Duration:
24 h
Dose descriptor:
other: EC20
Effect conc.:
> 4.2 - < 4.5 mg/L
Nominal / measured:
estimated
Conc. based on:
test mat.
Basis for effect:
other: gas production inhibition
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
>= 10.9 - <= 12.5 mg/L
Nominal / measured:
estimated
Conc. based on:
test mat.
Basis for effect:
other: gas production inhibition
Duration:
24 h
Dose descriptor:
other: EC90
Effect conc.:
> 18.1 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: gas production inhibition

Any other information on results incl. tables

Estimation of the EC0, EC20 and EC50 values:

  • No inhibition was observed at the dilution steps from 1:8 to 1:64, corresponding to concentrations >= 2.26 mg/L.
  • An enhanced gas production of 25% was observed in the dilutions from 1:16 to 1:64.
  • The EC90 was calculated as 42.7 mg/L (35.5 mg/L - 53.2 mg/L) in the spreadsheet (inc. in original report) by logarithmic regression. But in consideration to the extrapolation for this value in the calculation, with the indicated test data the EC90 should be estimated as > 18.1 mg/L.
  • the highest test concentration was the saturated solution with 18.1 mg/L.

Applicant's summary and conclusion

Validity criteria fulfilled:
not specified