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Environmental fate & pathways

Biodegradation in water and sediment: simulation tests

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Administrative data

Endpoint:
biodegradation in water: simulation testing on ultimate degradation in surface water
Type of information:
(Q)SAR
Adequacy of study:
weight of evidence
Study period:
2020
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:
Read-across discussed in Category Justification Document (CJD)
Cross-reference
Reason / purpose for cross-reference:
read-across: supporting information

Data source

Referenceopen allclose all

Reference Type:
publication
Title:
Unnamed
Year:
2005
Reference Type:
publication
Title:
Unnamed
Year:
1994
Reference Type:
publication
Title:
Unnamed
Year:
2000
Reference Type:
other: Computer QSAR model
Title:
Unnamed
Year:
2021
Report date:
2021

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other: ECHA Information Requirements R.6
Principles of method if other than guideline:
Episuite and the Biowin/BioHCWin models are well documented and commonly used QSARs for predicting the biodegradation potential of chemicals. Substances within LOA fall within the applicability domain of these models and they have been recommended by ECHA in the Information Requirement Guidelines.
BioHCwin v1.01 in EPISuite v4.11 (2013). The BioHCwin program was developed specifically for the biodegradation half-life prediction of petroleum hydrocarbons. Primary biodegradation half-lives for individual petroleum hydrocarbons are estimated using multiple linear regression against distinct molecular fragments, using a similar approach to several other biodegradation models such as those within the Biodegradation Probability Program (Biowin).

Test material

Constituent 1
Reference substance name:
Reference substance 002
Cas Number:
77-73-6

Results and discussion

Half-life of parent compound / 50% disappearance time (DT50)
Key result
Compartment:
water
DT50:
21.444 d
Type:
not specified
Remarks on result:
other: BioHCWin prediction
Transformation products:
not measured
Details on results:
For the purpose of the PBT assessment, the screening assessment was conducted using predicted biodegradability obtained by using EPI Suite v4.11.

Applicant's summary and conclusion

Conclusions:
The results of the BioHCwin for DCPD indicate a half-life of 21.4435 days.
Executive summary:

The use of a QSAR to predict the biodegradability of the substance is an appropriate technique as these substances clearly fall within the applicability domain of the model, with all substructures included in the model. The results indicate that the substance has a half life of 21.4435 days.

 

The use of QSAR estimates to predict the biodegradability of hydrocarbons because they are included in the training sets of the BIOWIN and BioHC models.The databases were created using experimental biodegradation data for compounds found in crude oil and its products, with biodegradation references obtained for each of these compounds, mainly from the BIOLOG and DATALOG files of EFDB, TOXLINE and American Chemical Society Chemical Abstracts as well as literature searches. For the BioHC model, a single recommended biodegradation half-life was chosen for use in the regression analysis from the primary biodegradation data that were compiled for each hydrocarbon structure.