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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Administrative data

toxicity to aquatic algae and cyanobacteria
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: QSAR calculation, reliable with restrictions

Data source

Reference Type:
other: Computer model
ECOWIN v1 ECOSAR Classes for Microsoft Windows
Nabholz V and Mayo-Bean K
Bibliographic source:
USEPA OPPT Risk Assessment Division

Materials and methods

Principles of method if other than guideline:
The Ecosar class program has been developed primarily for the evaluation of neutral organic compounds and organic classes with excess toxicity. The QSARs in the Ecosar program are developed for chemical classes based on measured test data that have been submitted by industry or they are developed by other sources for chemicals with similar structures, e.g., phenols. Using the measured aquatic toxicity values and estimated Kow values, regression equations can be developed for a class of chemicals. Toxicity values for new chemicals may then be calculated by inserting the Kow into the regression equation and correcting the resultant value for the molecular weight of the compound.
GLP compliance:
not specified

Test material

Details on test material:
Not applicable
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):Not applicable

Sampling and analysis

Details on sampling:
Not applicable

Test solutions

Details on test solutions:
Not applicable

Test organisms

Test organisms (species):
other: Algae
Details on test organisms:
Not applicable

Study design

Test type:
other: Not applicable
Water media type:
Post exposure observation period:
Not applicable

Test conditions

Not applicable
Test temperature:
Not applicable
Not applicable
Dissolved oxygen:
Not applicable
Not applicable
Nominal and measured concentrations:
Not applicable
Details on test conditions:
Not applicable

Results and discussion

Effect concentrations
96 h
Dose descriptor:
Effect conc.:
7.7 mg/L
Nominal / measured:
Conc. based on:
test mat.
Details on results:
calculated using the neutral organic QSAR.
Results with reference substance (positive control):
Not applicable
Reported statistics and error estimates:
Not applicable

Applicant's summary and conclusion

Validity criteria fulfilled:
not applicable
The calculated 96hr EC50 for butane is 7.7 mg/l.
Executive summary:

Members of this category are gases at standard temperature and pressure, so conducting an aquatic ecotoxicity test is technically difficult and based on exposure estimates the test may not be relevant. In addition, it is difficult to assess the toxicity of UVCB streams using standard test methods. Instead, it is more appropriate to consider the toxicity of representative components of these streams.

Therefore, the use of a QSAR to predict the ecotoxicity of representative components of these streams is an appropriate technique to use a part of a weight of evidence approach. The use of ECOSAR is appropriate for this Category as these streams falls within the applicability domain of the model.