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Environmental fate & pathways

Adsorption / desorption

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Description of key information

Conclusions for adsorption coefficient of 2,2-bis[[(2-ethyl-1-oxohexyl)oxy]methyl]propane-1,3-diyl bis(2- ethylhexanoate) are based on read across from a know category of analogue substances (notified under Directive 67/548/EEC (NONS) in 2003/2004 ) and on QSAR. The log Koc is estimated to be > 4.3.

Key value for chemical safety assessment

Additional information

For several compounds data on biodegradability are present, showing that the compounds investigated are not readily biodegradable. Only NONs dossier data is available, which does not present adequate robust study summaries. In addition, full study reports are not available for the majority of substances. 

Read across to structural analogue. Structural details are listed below. All members of this category of esters have a hydrophobic nature. Based on structural similarities of the substance of interest and the members of the category it was concluded that it was justified to apply read across for Biodegradation in water: screening tests.

 

REACH Annex XI, Paragraph 1.5 onGrouping of substances and read-across approach states as follows:

 

Substances whose physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a

regular pattern as a result of structural similarity may be considered as a group, or ‘category’ of substances. Application

of the group concept requires that physicochemical properties, human health effects and environmental effects or environmental fate may be predicted from data for reference substance(s) within the group by interpolation to other substances in the group (read-across approach). This avoids the need to test every substance for every endpoint. The Agency, after consulting with relevant stakeholders and other interested parties, shall issue guidance on technically and scientifically justified methodology for the grouping of substances sufficiently in advance of the first registration deadline for phase-in substances.

 

The similarities may be based on:

 

(1) a common functional group;

(2) the common precursors and/or the likelihood of common breakdown products via physical and biological

processes, which result in structurally similar chemicals; or

(3) a constant pattern in the changing of the potency of the properties across the category.

If the group concept is applied, substances shall be classified and labelled on this basis.

 

In all cases results should:

— be adequate for the purpose of classification and labelling and/or risk assessment,

— have adequate and reliable coverage of the key parameters addressed in the corresponding test method referred

to in Article 13(3),

— cover an exposure duration comparable to or longer than the corresponding test method referred to in

Article 13(3) if exposure duration is a relevant parameter, and

— adequate and reliable documentation of the applied method shall be provided.

Read across to this structural analogue is considered appropriate, as the substance shares a common data set and structure. Tabulated data below demonstrates the available study. This demonstrates similar characteristics across the group in terms of physico-chemical and toxicological behaviour. As such, it is deemed appropriate to read across to available data to fulfil this endpoint. 

Endpoint

Guideline

CAS 144971-11-9

CAS 131459-39-7

CAS 452-180-9

CAS 7299-99-2

Physchem

 

 

 

 

 

Melting/freezing / Pour point

OECD 102

< -80.5

< -36

-30

9 deg C

Boiling point

OECD 103

dec >175 deg C

399 deg C

386 deg C

415 deg C

Relative density

OECD 109

0.97

0.96

0.97

0.9634

Vapour pressure

OECD 104

5.7 E-03

1.9

0.38

0.000000306 Pa at 20 °C

Water solubility

OECD 105

<0.2 mgl

<0.1 mg/l

<0.2 mmg/l

< 0.4 µg/l.

n-Octanol-water partition coefficient

OECD 117 / 107

>6.7*

>7.0*

>6.7*

Read-across: > 6.7; Calculated at 12.34

Flash point or flammability

EU A9 / A10

215.5 deg c

260 deg c

274 deg c

213 deg c

Explosivity

EU 14

waived

waived

waived

Not explosive

Auto-flammability

EU A15

405

400

415

waived as FP > 200 Deg C

Viscosity

OECD 114

Not listed

Not listed

Not listed

44 at 40°C
6.2 at 100°C

Mammalian Toxicity

Acute oral toxicity

OECD 423

> 2000

> 2000

> 2000

> 2000 mg/kg bw

Ames test

OECD 471

negative

No data

negative

Negative

 

 

All members of the category have low water solubility and high Log Kow. Since the few substances tested by experiment were strongly retained on the stationary phase, the log Koc for most substances was determined by QSAR calculation. All members of the category have a Log Koc>= 4.3 (Koc > 19952)meaning that they absorb strongly to organic material. Hence mobility in soil will be low. However, as the substance is not manufactured in Europe and at formulation or use waste is not disposed of via a waste water treatment plant, but incinerated, the environment is not expected to be exposed.

 

Using EPISuite 4.0 the log Kocof 2,2-bis[[(2-ethyl-1-oxohexyl)oxy]methyl]propane-1,3-diyl bis(2- ethylhexanoate) (EC# 230 -743 -8) was calculated as 9.2 (estimate from MCI (Molecular Connectivity Index)) and 7.6 (estimated from log Pow)

 

Log Koc can provide insight as to whether a material will cling to soils or sediments in water and whether they will desorb or be tightly bound. Based on information from NTIS ((Review of Exposure Assessment Guidelines, September 1996), approximate indications of relative soil absorption potential are as follows:

 

Low potential: Koc = 1 to 100, log Koc = 0 - 2

Moderate potential: Koc = 100 to 10,000, log Koc = 2 - 4

High potential: Koc = 10,000 to 10,000,000, log Koc 4 - 7

 

A high potential would indicate that a material would bind tightly to soils and sediments and thus, reduce overall exposure potential.