1,2,4-trimethylbenzene

Toxicity to soil macroorganisms except arthropods

Administrative data

Endpoint:

toxicity to soil macroorganisms except arthropods: short-term

Type of information:

(Q)SAR

Adequacy of study:

other information

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: QSAR calculation, reliable with restriction

Justification for type of information:

QSAR prediction: migrated from IUCLID 5.6

Data source

Reference

Reference Type:

other: computer model

Title:

ECOWIN v1 ECOSAR Classes for Microsoft Windows

Author:

Nabholz V and Mayo-Bean K

Year:

2009

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:

no

Remarks:

not applicable

Test material

Test material information

Constituent 1

Reference substance name:

1,2,4-trimethylbenzene

EC Number:

202-436-9

EC Name:

1,2,4-trimethylbenzene

Cas Number:

95-63-6

Molecular formula:

C9H12

IUPAC Name:

1,2,4-trimethylbenzene

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

Analytical monitoring:

no

Details on sampling:

not applicable

Test substrate

Vehicle:

no

Details on preparation and application of test substrate:

not applicable

Test organisms

Test organisms (species):

other: earthworm

Animal group:

annelids

Details on test organisms:

not applicable

Study design

Study type:

other: calculated

Substrate type:

not specified

Limit test:

no

Total exposure duration:

14 d

Post exposure observation period:

not applicable

Test conditions

Test temperature:

not applicable

pH:

not applicable

Moisture:

not applicable

Details on test conditions:

not applicable

Nominal and measured concentrations:

not applicable

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

141.598 other: ppm

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

calculated using the neutral organics QSAR and a measured log kow of 3.63. ECOSAR model reports that the chemical may not be soluble enough to measure this predicted effect.

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

Remarks:

Calculated

Conclusions:

The estimated 14 day LC50 for earthworms is 141.598ppm

Executive summary:

The ECOSAR model is a reliable and appropriate QSAR model to apply to 1,2,4 -trimethylbenzene 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.