Alkenes, C6-11 (branched), hydroformylation products, distn. residues, heavy cracked fraction

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

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 data used as input, validity, applicability and adequacy of the result are in the attached document.
The registered substance, Alkenes, C6-11, hydroformylation products, distillation residues, heavy cracked fractions, 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) is a framework that relates toxicity to the physicochemical properties of a nonpolar organic constituent. The TLM framework was validated previously for acute and chronic aquatic toxicity endpoints. The constituents in this substances are within the scope of the TLM and EqP frameworks.

Data source

Reference

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

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

Constituent 1

Reference substance name:

Alkenes, C6-11 (branched), hydroformylation products, distn. residues, heavy cracked fraction

EC Number:

701-314-7

Molecular formula:

CnH2n+2O2. n=24-33

IUPAC Name:

Alkenes, C6-11 (branched), hydroformylation products, distn. residues, heavy cracked fraction

Details on test material:

Alkenes, C6-11, hydroformylation products, distn. residues,heavy cracked fraction is a yellowing liquid comprised of oxygenated hydrocarbons.

Specific details on test material used for the study:

Alkenes, C6-11, hydroformylation products, distn. residues, heavy cracked fraction is a UVCB substance consisting of a number of 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 relevant components are based upon a range of branching of the molecules that make up the dimer and trimer molecules, and again, are based on the best available analytical data, and process knowledge. The representative structures and relative mass balance for each group of constituents are presented in the attached document.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

1 330 mg/L

Nominal / measured:

nominal

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EL10

Effect conc.:

266 mg/L

Nominal / measured:

nominal

Basis for effect:

growth rate

Remarks on result:

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

Applicant's summary and conclusion

Conclusions:

(Q)SAR estimations for the registered substance resulted in a 72 h EL50 to green algae of 1330 mg/L; and EL10 of 266 mg/l.

Executive summary:

The registered substance, Alkenes, C6-11, hydroformylation products, distillation residues, heavy cracked fractions, 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) has been applied to aquatic toxicity and is considered fit for purpose.