Montan wax

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study according to OECD Test Guideline 117 under GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)

GLP compliance:

yes (incl. QA statement)

Type of method:

other: calculation method

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Reference substance name:

Montan wax

EC Number:

232-313-5

EC Name:

Montan wax

Cas Number:

8002-53-7

Molecular formula:

As montan wax is a UVCB, a molecular formular cannot be specified.

IUPAC Name:

Montan wax

Results and discussion

Partition coefficient

Type:

log Pow

Partition coefficient:

>= 1.49 - <= 2.57

Temp.:

20 °C

Remarks on result:

other: pH is not indicated. However, due to the low solubility, it can be assumed that the pH remained approximately neutral.

Details on results:

Water solubility was assumed to be between 0.1 (worst case) and 1.2 mg/L (best case) based on the available study of the water solubility.
Mean saturation in octanl of five samples was 36.9 mg/L ranging between 29.8 and 44.4 mg/L.
The blank gave only a marginal dry residue (0.1 mg). Therefore, no correction of the determined concentrations was necessary.
Log Pow range was calcualted by the above given formulae using both the best and worst case water solubility.

Applicant's summary and conclusion

Conclusions:

In a study according to OECD test guideline 117 under GLP, the log Pow of the test substance was calculated to be in the range from 1.49 to 2.57.

Executive summary:

In a preliminary test, the test substance was mixed with methanol / water 75/25 (%V/V) and set into an ultrasonic bath. No dissolution could be observed. The HPLC analysis of the solution according to the EU Method A.8 “Partition Coefficient“ yielded no signal of the test item. This was considered to be caused by the insolubility of the test item in the mobile phase. Therefore, it was not possible to determine the log Pow of Montan wax by HPLC. As the test item is a mixture of many components with different dissolution behaviours in n-octanol and water, a determination is not possible with the shake flask method, either. Therefore, an estimation of the solubility in water and in octanol was used to calculate an approximated log Pow.

The measured dry residues are low. Therefore, the determination of the saturation concentration is not very precise. Calculation of the corresponding log Pow shows that the influence on the result is not so relevant. On base of the minimum/maximum water solubility of 0.1/1.2 mg/L, the log Pow was calculated to be in the range from 1.49 to 2.57.

No observations arousing doubts concerning the accuracy of the results and the validity of the study were made.