N-ethyl-o-toluidine

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

1. SOFTWARE : EPI Suite

2. MODEL (incl. version number) : ECOSAR v1.00

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL : SMILE notation

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
The structure-activity relationships (SARs) presented in this program are used to predict the aquatic toxicity of chemicals based on their similarity of structure to chemicals for which the aquatic toxicity has been previously measured.  Most SAR calculations in the ECOSAR Class Program are based upon the octanol/water partition coefficient (Kow).  Various surfactant SAR calculations are based upon the average length of carbon chains or the number of ethoxylate units.
SARs have been used by the U.S. Environmental Protection Agency since 1981 to predict the aquatic toxicity of new industrial chemicals in the absence of test data.  The acute toxicity of a chemical to fish (both fresh and saltwater), water fleas (daphnids), and green algae has been the focus of the development of SARs, although for some chemical classes SARs are available for other effects (e.g, chronic toxicity and bioconcentration factor) and organisms (e.g., earthworms).  SARs 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 estimated Kow into the regression equation and correcting the resultant value for the molecular weight of the compound.
There are currently 130 chemical classes programmed into ECOSAR.  For those 130 classes, there are a total of 440 QSARs based on publicly available experimental data and confidential studies collected under the EPA New Chemicals Program.  For each class, a standard EPA New Chemicals Program aquatic toxicity profile will be created using available QSARs and/or alternate SAR approaches and professional judgment.  This standard profile typically contains 3 acute values, and 3 chronic values for fish, daphnid, and green algae.  In an effort to complete a profile for each class, 173 endpoints have been estimated using alternative approaches such as acute-to-chronic ratios and substitute QSARs based on scientific judgment.
ECOSAR estimates log Kow values using the US EPA's KOWWIN Program.  Information about the KOWWIN Program its log Kow estimations are available in the on-line KOWWIN Help File.
The ECOSAR Class Program is a computerized version of the ECOSAR analysis procedures as currently practiced by the Office of Pollution Prevention and Toxics (OPPT).  It has been developed within the regulatory constraints of the Toxic Substances Control Act (TSCA).  It is a pragmatic approach to SAR as opposed to a theoretical approach

5. APPLICABILITY DOMAIN
The category group of the substance of interest falls under the applicability domain of the model.

6. ADEQUACY OF THE RESULT
The predictions are considered as adeguate to predict the toxicity of the substance.

Data source

Reference

Reference Type:

other: (Q)SAR prediction

Title:

ECOSAR v1.00

Author:

EPI Suite

Year:

2018

Materials and methods

Test guideline

Qualifier:

no guideline required

GLP compliance:

no

Remarks:

not relevant

Test material

Specific details on test material used for the study:

not relevant

Sampling and analysis

Analytical monitoring:

not required

Details on sampling:

not relevant

Test solutions

Vehicle:

no

Remarks:

not relevant

Details on test solutions:

not relevant

Test organisms

Test organisms (species):

not specified

Details on test organisms:

Fish

Study design

Test type:

other: prediction

Test conditions

Hardness:

not relevant

Test temperature:

not relevant

pH:

not relevant

Dissolved oxygen:

not relevant

Salinity:

not relevant

Conductivity:

not relevant

Nominal and measured concentrations:

not relevant

Details on test conditions:

not relevant

Reference substance (positive control):

not required

Results and discussion

Effect concentrations

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

27.27 mg/L

Nominal / measured:

not specified

Conc. based on:

not specified

Basis for effect:

not specified

Applicant's summary and conclusion

Conclusions:

LC50 (Fish 96-hr): 27.270 mg/L (est)