Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

short-term toxicity to aquatic invertebrates
Type of information:
Adequacy of study:
key study
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: QSAR calculation, reliable with restrictions
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6

Data source

Reference Type:
other: computor 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 applicable

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):
Daphnia sp.
Details on test organisms:
Not applicable

Study design

Test type:
other: Not applicable
Water media type:
not specified
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
48 h
Dose descriptor:
Effect conc.:
11 mg/L
Nominal / measured:
Conc. based on:
test mat.
Details on results:
calculated using the neutral organic QSAR. Data entered: log Kow 2.4, melting point = -105.52, water solubility = 263mg/l
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 estimated 48hr LC50 for Daphnids is 11 mg/l
Executive summary:

The estimated 48hr LC50 for Daphnids is 11 mg/l. Measured data are not available for butene for this endpoint. Due to the practical difficulties associated with the ecotoxicity testing of gases (i.e. maintaining exposure concentrations) the use of QSAR toxicity estimates is an appropriate alternative. The ECOSAR model is a reliable and appropriate QSAR model to apply to butene as it is based on a related chemical dataset that calculates the toxicity of neutral organic hydrocarbons whose mode of action is non-polar narcosis. The endpoint calculated here is therefore a reasonable estimate of its baseline toxicity.