Registration Dossier

Administrative data

Endpoint:
bioaccumulation: aquatic / sediment
Type of information:
other: Expert Statement
Adequacy of study:
key study
Study period:
2010
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Statement is based on valid study data.

Data source

Reference
Reference Type:
other: Company data
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Principles of method if other than guideline:
The physicochemical properties of the test substance, and extensive ecotoxicity studies provide strong support in determining the bioaccumulation potential for this substance, and therefore may substitute for the experimentation of in vivo effects.
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Radiolabelling:
no

Results and discussion

Any other information on results incl. tables

Bioaccumulation (B) Assessment

Aquatic bioaccumulation

  • Screening data

Based on molecular size, the representative structures that comprise the majority of this UVCB substance have a molecular diameter greater than 2.0 nm which is greater than the ECHA criterion of 1.5 to 1.7 below which bioaccumulation potential is a concern.

  • Measured data

ECHA Guidance R7c 10.3.2 states that QSAR and read across can be used for the assessment of bioaccumulation on the chemical of interest. Measured data on the structurally similar substance CAS#115-86-6 (as identified by Toxmatch Tanimoto fingerprint) shows measured data for multiple fish species with BCF values less than 1,000.

  • Summary and discussion of bioaccumulation

Based on molecular size, the representative structures that comprise the majority of this UVCB substance have a molecular diameter greater than 2.0 nm which is greater than the ECHA criterion of concern for bioaccumulation. Based on read across to structurally similar substances, using the Toxmatch software, Tanimoto index, and Caesar database, the representative structures in this UVCB have low bioaccumulation potential with BCF values in various fish species all less than 2,000. Based on BCF predictions using QSAR models found in EPISuite and CAESAR, the representative structures in this UVCB have a low potential for bioaccumulation potential.

Table32. Criteria for Bioaccumulation

Parameter

ECHA Criterion*

Results for Substance

Screening Assignment based on Data for Substance

Octanol-water partitioning coefficient

Log Kow ­<4.5

3.7 to 7.8

Definitive assignment not possible based on range of Kow values for complex mixture; defer to experimental results, modeling results, and weight of evidence

Molecular size

Molecular diameter >1.5 to 1.7 nm

Representative structures for the majority of the UVCB have molecular diameters greater than 2.0 nm**

Not vB

Structural similarity or class of chemicals

Similarity to class of chemicals known to accumulate in living organisms?

Material is not structurally similar to any known materials that fulfill the screening criteria

Not B

Not vB

BCF in fish

>2,000 L/kg B

>5,000 L/kg B

Rainbow trout 271 and 573

Goldfish 150

Fathead minnow 573

Medaka 144

(for read across to structurally similar substance CAS# 115-86-6. data from EPA Ecotox database)

Not B

Not vB

QSAR

Log Kow or BCF Prediction

CAESAR and EPISUITE

Not B

Not vB

* Based on criterion described in ECHA 2008, “Guidance on information requirements and chemical safety assessment. Chapter R.11: PBT Assessment”

** Molecular diameter measured using Accelrys Molecular Modelling software

Table33. Summary of Bioaccumulation Potential by Representative Structures

Representative Structure

Property

Screening Assignment

Figure 1

CAESAR predicted BCF 11

Molecular diameter 2.4 nm

Structurally similar chemicals in CAESAR have measured BCF values less than 2000

Not B

Not vB

Figure 2

CAESAR predicted BCF 25

Molecular diameter 2.1 nm

Structurally similar chemicals in CAESAR have measured BCF values less than 2000

Not B

Not vB

Figure 3

CAESAR predicted BCF 3

Molecular diameter 2.2 nm

EPISuite BCF modelling predicts BCF in fish of 61

Structurally similar chemicals in CAESAR have measured BCF values less than 2000

Not B

Not vB

Figure 4

CAESAR predicted BCF 98

Structurally similar chemicals in CAESAR have measured BCF values less than 2,000

Structurally similar to CAS# 115-86-6 based on Tanimoto fingerprint

Measured BCF data in multiple fish species (source: EPA Ecotox database) show BCF values less than 1,000

Not B

Not vB

Figure 5

CAESAR predicted BCF 34

EPISuite BCF modeling predicts BCF in fish of 159

Structurally similar chemicals in CAESAR have measured BCF values less than 2,000

Not B

Not vB

 

Terrestrial bioaccumulation

Data on terrestrial bioaccumulation are not considered to be required for the substance. In accordance with REACH legislation the test does not need to be conducted if direct and indirect exposure to the terrestrial compartment is unlikely.  In addition, the results of the CSR for this substance and the PEC/PNEC ratios for the local and regional terrestrial compartment indicate no risk.  ECHA Chapter R.7B guidance states that if the PEC/PNEC ratio is below 1, then no risk for the compartment is indicated and there is no need to perform further tests.  Furthermore, this substance does not meet the B or vB criterion and it is not considered to be a PBT.

 

Conclusion:

The test materials is not bioaccumulative.

Applicant's summary and conclusion

Validity criteria fulfilled:
not applicable
Conclusions:
Based on the weight of evidence (measured Log Kow data, and QSAR predictions), this substance is expected to have low bioaccumulation potential. This substance does not meet the criteria of concern for bioaccumulation.