Reaction mass of benzyl 2-ethylhexyl adipate and bis(2-ethylhexyl) adipate and dibenzyl adipate

Toxicity to soil microorganisms

Administrative data

Endpoint:

toxicity to soil microorganisms

Type of information:

experimental study planned

Justification for type of information:

TESTING PROPOSAL ON TERRESTRIAL MICROORGANISMS, OECD 216

NON-CONFIDENTIAL NAME OF SUBSTANCE:
- Name of the substance on which testing is proposed to be carried out: ‘Reaction mass of benzyl 2-ethylhexyl adipate and bis(2-ethylhexyl) adipate and dibenzyl adipate’ (EC No. 905-983-8)
CONSIDERATIONS THAT THE GENERAL ADAPTATION POSSIBILITIES OF ANNEX XI OF THE REACH REGULATION ARE NOT ADEQUATE TO GENERATE THE NECESSARY INFORMATION:
- Available GLP studies: For ‘Reaction mass of benzyl 2-ethylhexyl adipate and bis(2-ethylhexyl) adipate and dibenzyl adipate’ (EC No. 905-983-8) no studies assessing the toxicity on terrestrial microorganisms are available yet.
- Available non-GLP studies: No further studies on terrestrial toxicity on microorganisms are available for ‘Reaction mass of benzyl 2-ethylhexyl adipate and bis(2-ethylhexyl) adipate and dibenzyl adipate’ (EC No. 905-983-8)
- (Q)SAR: There are no QSAR models available for this higher tier ecotoxicological endpoint that are sufficiently validated and acceptable (according to OECD Q/SAR validation criteria).
- Weight of evidence & Grouping and read-across: ‘Reaction mass of benzyl 2-ethylhexyl adipate and bis(2-ethylhexyl) adipate and dibenzyl adipate’ (EC No. 905-983-8) is not part of a category and no data on terrestrial toxicity on microorganisms for ‘Reaction mass of benzyl 2-ethylhexyl adipate and bis(2-ethylhexyl) adipate and dibenzyl adipate’ (EC No. 905-983-8) or related substances is available. There is thus no data supporting a weight of evidence or read-across approach and further testing is deemed necessary.

CONSIDERATIONS THAT THE SPECIFIC ADAPTATION POSSIBILITIES OF ANNEXES VI TO X (AND COLUMN 2 THEREOF) OF THE REACH REGULATION ARE NOT ADEQUATE TO GENERATE THE NECESSARY INFORMATION:
- Recent experimental results from a chronic daphnia study (2021, according to OECD Guideline for the Testing of Chemicals, No. 211, "Daphnia magna, Reproduction Test) indicate chronic toxicity of ‘Reaction mass of benzyl 2-ethylhexyl adipate and bis(2-ethylhexyl) adipate and dibenzyl adipate’ (EC No. 905-983-8) towards aquatic invertebrates. Based on the determined NOEC (4.34 µg/L), the T criterion is fulfilled (NOEC ≤ 0.01 mg/L for marine/freshwater organisms) and there is indication that the registered substance is very toxic to aquatic organisms. In addition, the calculated range of the partition coefficient (logKOW between 4.80 and 8.12, individually calculated for the components) and the range of the adsorption coefficient (logKOC between 3.45 and 5.29, individually calculated for the components) are both indicative for a high adsorptive potential. Thus, based on the indications to be very toxic to aquatic organism and to be highly adsorptive, the registered substance is assigned to soil hazard category 4 as described in REACH Guidance document R7.c, Version 3.0 (June 2017). According to Table R.7.11-2 the screening assessment based on EPM is not recommended for substances assigned to hazard category 4. In order to derive the PNECsoil, and to assess the toxicity towards the terrestrial compartment, experimental studies are required.
The registrant has carefully considered the available adaptation possibilities applicable for the discussed endpoint. Based on the lack of studies conducted according to GLP (or with acceptable restrictions) on toxicity testing on soil microorganisms for the substance, it is deemed necessary to further investigate the toxicity potential of the substance according to Annex IX 9.4.2 REACh regulation.
FURTHER INFORMATION ON TESTING PROPOSAL IN ADDITION TO INFORMATION PROVIDED IN THE MATERIALS AND METHODS SECTION:
- The registrant intends to perform the toxicity on soil microorganisms according to OECD guideline 216, Soil Microorganisms: Nitrogen Transformation Test. According to the guideline, the study design of this study will fit to the physico-chemical properties of the test substance, as this study can deal with substances with low water solubility.

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 216 (Soil Microorganisms: Nitrogen Transformation Test)

Deviations:

not applicable

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Benzyl 2-ethylhexyl adipate

EC Number:

261-234-9

EC Name:

Benzyl 2-ethylhexyl adipate

Cas Number:

58394-64-2

Molecular formula:

C21H32O4

IUPAC Name:

benzyl 2-ethylhexyl adipate

Constituent 2

Reference substance name:

Bis(2-ethylhexyl) adipate

EC Number:

203-090-1

EC Name:

Bis(2-ethylhexyl) adipate

Cas Number:

103-23-1

Molecular formula:

C22H42O4

IUPAC Name:

bis(2-ethylhexyl) adipate

Constituent 3

Reference substance name:

Dibenzyl adipate

EC Number:

219-516-4

EC Name:

Dibenzyl adipate

Cas Number:

2451-84-5

Molecular formula:

C20H22O4

IUPAC Name:

dibenzyl adipate