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Environmental fate & pathways

Biodegradation in water: screening tests

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Administrative data

Endpoint:
biodegradation in water: screening tests
Type of information:
(Q)SAR
Adequacy of study:
supporting study
Study period:
2013
Reliability:
2 (reliable with restrictions)
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2013
Report date:
2013

Materials and methods

Principles of method if other than guideline:
QSAR approach: Different tools were used, when possible, in order to apply a consensus approach and thus enhance the reliability of the predictions. In fact, a single in silico prediction model may provide acceptable results. However, by definition all models are simulation of reality, and therefore they will never be completely accurate; sometimes a single model will not work. When multiple models and multiple approaches are combined in a single consensus score, more accurate predictions can be achieved.
If two prediction methods that use data and different approaches are consistent, the reliability of prediction is better. The errors of a model/approach should be different from another, and therefore compensate.

Several computational tools are nowadays available for applying in silico approaches. Among them, for QSAR predictions the following was selected and used for the endpoint:
Estimation Program Interface (EPI) Suite (US Environmental Protection Agency’s Office of Pollution Prevention and Toxics and Syracuse Research Corporation (SRC), version 4.10) is a collection of several modules for the prediction of physicochemical and environmental fate endpoints developed by the Environmental Protection Agency (EPA) and by the Syracuse Research Corporation (SRC). It allows to transfer a single SMILES notation to thirteen separate structure estimation programs that calculate several properties
Toxtree (Ideaconsultant, version 2.5.1) is a flexible and user-friendly open-source application that places chemicals into categories and predicts various kinds of toxic effect by applying decision tree approaches. The following decision trees are currently implemented: the Cramer classification scheme, Verhaar scheme for aquatic modes of action, rulebases for skin and eye irritation and corrosion, Benigni-Bossa rulebase for mutagenicity and carcinogenicity, structural alerts for identification of Michael Acceptors, START rulebase for persistence / biodegradation potential.
GLP compliance:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
Bis[2-[2-(2-butoxyethoxy)ethoxy]ethyl] adipate
EC Number:
265-807-4
EC Name:
Bis[2-[2-(2-butoxyethoxy)ethoxy]ethyl] adipate
Cas Number:
65520-46-9
Molecular formula:
C26H50O10
IUPAC Name:
1,6-bis({2-[2-(2-butoxyethoxy)ethoxy]ethyl}) hexanedioate
Test material form:
other: liquid

Results and discussion

Any other information on results incl. tables

BIOWIN ready biodegradability prediction

Chemical

Ultimate

Biodegradation

Biowin3

Linear MITI

model

Biowin5

Non linear

MITI model

Biowin6

Ready

biodegradability

prediction

bis(2-(2-(2-butoxyethoxy)ethoxy)ethyl) adipate

Weeks-

Readily biodegradable

Readily biodegradable

YES

Toxtree ready biodegradability prediction

Chemical

Toxtree biodegradability

bis(2-(2-(2-butoxyethoxy)ethoxy)ethyl) adipate

Persistent

Applicant's summary and conclusion

Interpretation of results:
other: persistent
Conclusions:
BIOWIN results: the target chemical was predicted READILY BIODEGRADABLE; and Toxtree result: bis(2-(2-(2-butoxyethoxy)ethoxy)ethyl) adipate was predicted PERSISTENT chemicals because of the identification of the ether aliphatic group, which is a functional group associated with low biodegradability.
A consensus assessment was performed according to the precautionary approach, which led to the conclusion: PERSISTENT.
Executive summary:

Consensus ready biodegradability prediction

Chemical

BIOWIN ready

biodegradability

prediction

Toxtree biodegradability

CONSENSUS PREDICTION

bis(2-(2-(2-butoxyethoxy)ethoxy)ethyl) adipate

YES

Persistent

Persistent