Registration Dossier

Physical & Chemical properties

Partition coefficient

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Administrative data

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The method migh underestimate the real logKow. Only dublicate tests.

Data source

Reference
Reference Type:
other: Body responsible for the test
Title:
Unnamed
Year:
1994
Report Date:
1994

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: OECD method 107, EEC method A8
Principles of method if other than guideline:
HPLC Hewlett Packard HP1050
Column Spherisorb 5 oDS (25 cm x 4.6 mm id)
Mobil phase acetonitrile 60:40 v/v
Flow rate 1 ml/min
Test temp 21 C.
GLP compliance:
yes
Type of method:
HPLC method
Partition coefficient type:
octanol-water

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Fine white powder, purity > 98 %.

Study design

Analytical method:
other: UV detector254 nm detector

Results and discussion

Partition coefficient
Type:
log Pow
Partition coefficient:
2.7
Temp.:
21 °C
Remarks on result:
other: pH not determined in the test.

Applicant's summary and conclusion

Conclusions:
Doubt was raised about the accuracy of the loqKow value in the original risk assessment report for the notification of this substance. A calculated LogKow of 5.32 was used for environmental exposure assessment because doubt regarding the reliability of the experimental LogKow. Doubt was also raised in 1995 about the determined water solubility and comparison was made in the risk assessment with calculated water solubility (116,7 mg/l. The registrant made a new calculation in Epi Suite program KowWin 1.01 of Water solubility and this resulted in a value of 0.002632 mg/l at 25°C. This is even lower than experimental determined water solubility.
The registrant claims that the experimentally determined LogKow seems the most suitable value to use for the environmental risk assessment. With better analysis technique this experimental determination could be repeated with a traditional test in a shake flask, to verify the result from the HPLC method.

A QSAR determination as comparison was made of the registrant with Software EpiSiute KowWin ver. 1.67. This calculation gave also a higher logKow of 5,3 This calculated logkow will give a calculated value of BCF 2415 with EpiSuite Software BCfwin ver. 2.15. This QSAR calculation is not chosen by the registrant. The experimental data of log Kow is considered accurate and is used for the total environmental assessment and the new proposal for environmental classifications of the product.