1,2-Benzenedicarboxylic acid, isodecyl ester, manuf. of, by-products from

Toxicity to soil macroorganisms except arthropods

Administrative data

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

2019

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:

Detailed information covering the calculation model, compositional model, compositional data used as input, validity, applicability and adequacy of the result are in the attached document.

The registered substance is a complex mixture whose constituents within the mixture have variable physiochemical properties. Therefore, a modeling framework is needed to account for the bioavailability of the constituents in the mixture, which was then used to predict the toxicity of the substance as a whole.

The target lipid model (TLM) is a framework that relates toxicity to the physicochemical properties of a nonpolar organic constituent. The TLM, and HC5, have been applied to soils and sediment using equilibrium partitioning (EqP) model. This framework utilizes organic carbon partition coefficients (KOC) to convert aquatic based effect levels (CW) to bulk soil- and sediment-based effect levels. The combined TLM-EqP framework was validated previously for soil and sediment acute and chronic toxicity endpoints. The constituents in this substance are within the scope of the TLM and EqP frameworks.

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Refinement and validation of TLM-derived HC5 values. Independent review.

Author:

McGrath JA, Di Toro DM, Fanelli CJ

Year:

2015

Bibliographic source:

HDR, Mahwah, NJ

Reference 2

Reference Type:

publication

Title:

Extension and validation of the target lipid model for deriving predicted no-effect concentrations for soils and sediments

Author:

Redman AD, Parkerton TF, Paumen ML, McGrath JA, den Haan K, DiToro DM

Year:

2014

Bibliographic source:

Envrionmental Toxicology and Chemistry Vol. 33, No. 12, pp. 2679-2687 (2014)

Materials and methods

Principles of method if other than guideline:

The target lipid model (2015) as described in the cited reference was used to determine aquatic effect levels following an estimation of initial loading of the registered substance and its constituents in the substrate. A full explanation of the calculation method is provided in the 'attached justification'. For model description and justification of QSAR prediction: see fields 'justification for type of information' and 'attached justification'.

Test material

Test material information

1

Reference substance name:

1,2-Benzenedicarboxylic acid, isodecyl ester, manuf. of, by-products from

EC Number:

271-079-9

EC Name:

1,2-Benzenedicarboxylic acid, isodecyl ester, manuf. of, by-products from

Cas Number:

68515-38-8

Molecular formula:

n/a

IUPAC Name:

1,​2-​Benzenedicarboxylic acid, isodecyl ester, manuf. of, by-​products from

Specific details on test material used for the study:

The registered substance is a UVCB substance consisting of a number of hydrocarbons and oxygenated hydrocarbon components, covering a wide range of carbon numbers and structures. The relevant components were determined based on the best available analytical data and process knowledge (see dossier sections 1.2 Composition and 1.4 Analytical methods). The representative structures and relative mass balance for each group of constituents are presented in the attached document.

Test organisms

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

28 d

Dose descriptor:

LC50

Effect conc.:

2.83 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Effect concentrations 2

Duration:

56 d

Dose descriptor:

EC10

Effect conc.:

0.566 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: Chronic endpoints estimated using typical acute-to-chronic ratio of 5

Applicant's summary and conclusion

Conclusions:

(Q)SAR estimations resulted in a LC50 of 2.83 mg/kg dw and an EC10 of 0.566 mg/kg dw for the earthworm.

Executive summary:

The registered substance is a complex mixture whose constituents within the mixture have variable physicochemical properties. Therefore, a modeling framework is needed to account for the bioavailability of the constituents in the mixture, which was then used to predict the toxicity of the substance as a whole. The target lipid model (TLM) and HC5, have been applied to soils and sediment using equilibrium partitioning (EqP) model. Further, an exposure assessment was performed using representative constituents, and RCR values of the individual constituents were summed to estimate the RCR values for the registered substance. RCR values below 1 were safely achieved for soil, freshwater and marine sediments, indicating a low level of risk to these environmental compartments. As such, modeled data are considered fit for purpose.