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Ecotoxicological information

Toxicity to microorganisms

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Administrative data

Endpoint:
toxicity to microorganisms
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The study was well documented and meets generally accepted scientific principles, but was not conducted in compliance with GLP.

Data source

Reference
Reference Type:
publication
Title:
Comparison of the toxicity thresholds of water pollutants to bacteria, algae, and protozoa in the cell multiplication inhibition test.
Author:
Bringmann G, Kuhn R
Year:
1980
Bibliographic source:
Water Research 14(3): 231-241.

Materials and methods

Test guideline
Qualifier:
no guideline followed
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
not specified

Test organisms

Test organisms (species):
Entosiphon sulcatum

Study design

Test type:
other: Cell multiplication inhibition test
Water media type:
freshwater
Total exposure duration:
72 h
Remarks on exposure duration:
Incubation period

Test conditions

Test temperature:
25 degC
Details on test conditions:
TEST SYSTEM
- Test vessel: 300 ml Erlenmeyer flasks

- Test vessel content: 8ml culture liquid. 8ml stock solution I, 2ml united preliminary protozoan cultures (approx. impulses 15000/ml)I, and 10ml each of bacterial suspension (or 10ml each of saline for the dilution series not inoculated) and 2ml of suspension of inactivated bacteria from a preliminary bacterial culture having a known extinction value.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Double distilled water

OTHER TEST CONDITIONS
- Adjustment of pH: Pollutant solution adjusted to pH6.9 using the minimum volume of hydrochloric acid or caustic potash.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable)
- After incubating, add 10% of a 1.1%NaNO3 solution in double distilled water filtered through a membrane filter (pore size 0.2um) to each falsk and determine the number of protozoa by means of a cell counter.


TEST CONCENTRATIONS
- Spacing factor for test concentrations: Four parallel dilution series, 1:2 to 1:2E+14 v/v. One series inoculated, one not.
Reference substance (positive control):
not required
Remarks:
not applicable

Results and discussion

Effect concentrations
Duration:
72 h
Dose descriptor:
other: TT or EC3
Effect conc.:
44 mg/L
Basis for effect:
other: cell multiplication inhibition

Applicant's summary and conclusion

Conclusions:
A toxicity threshold (TT) value for bacteria (Entosiphon sulcatum) of 44 mg/l was determined in a reliable study conducted according to generally accepted scientific principles.