Hexafluoropropene, oxidized, oligomers, reduced, fluorinated

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

November 2013 to March 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

OECD Guideline-conform study conducted under GLP.

Qualifier:

according to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

shake-flask method to: flask method

Partition coefficient type:

octanol-water

Analytical method:

gas chromatography

Key result

Type:

log Pow

Partition coefficient:

5.58

Temp.:

20 °C

pH:

5.3

Remarks on result:

other:

Remarks:

pH of the aqueous phase (water HPLC grade) was measured at the end of the Kow determination.

Details on results:

The whole procedure was conducted at room temperature (ca. 20°C) and the pH value of the aqueous phase was 5.3.

Ratrio O:W	Test vessel	Test item concentration in water (microgram/L)	Test item concentration in octanol (microgram/L)	Kow	mean Kow	mean Log Kow
1:1	A	10,18	10180000,00	384066,80	397378,049	5.599
	B	9,72	9720000,00	410689,30
1:2	A	10,50	10500000,00	368314,29	368393,3857	5.566
	B	10,54	10540000,00	368472,49
2:1	A	10,27	10270000,00	384985,39	388279,7342	5.589
	B	9,72	9720000,00	391574,07
				Mean:	384702.9	5.58
				RSD%:	4.11%	0.32%

Conclusions:

The test item showed grater affinity for n-octanol than for water. The mean Log Kow calculated basing on the experimental data was 5.58.

Executive summary:

The Partition Coefficient n-Octanol-water of the test item was determined under GLP according to OECD guideline No. 107 and EU method A.8, Partition Coefficient (n-octanol / water), Shake Flask Method.

 

In the preliminary test, in order to prepare a 0.01 M solution as suggested by A.8 method, and considering the molecular weight = 400 g/mol for the test item, a 4.0 g/L solution was prepared in the n-octanolic phase saturated with water derived from the original equilibrated mixture.

 

A solution containing a target concentration of 4197.6 microgram/mL, taking into account its 99 % purity, was prepared weighting the test item and dissolving it in the n-octanolic phase (saturated with water).

Three tests, using different ratios of the two phases (1.1, 1:2, 2:1 ) were performed. For each ratio, duplicate test vessels were prepared.

 

The test vessels were shaken for 2 hours on a mechanical shaker; that time elapsed, the two phases were separated by a 250 mL separatory funnel and analyzed by GC coupled with a FID detector. Calculations of analytical concentrations were made by an external standard.

 

All the procedure was conducted at room temperature (ca. 20 °C) and the pH value of the aqueous phase was 5.3.

 

The test item showed greater affinity from octanol than for water. Basing on the experimental data the mean Kow was calculated to be 384702.9 (RSD = 4.11%) and mean Log Kow was calculated to be 5.58 (RSD = 0.32 %).

Description of key information

The experimental determination of the partition coefficient Kow of GALDEN LMW was carried out according to the shake-flask method described in the OECD Guideline No. 107.

Log Kow of GALDEN LMW is 5,58.

Key value for chemical safety assessment

Log Kow (Log Pow):

5.58

at the temperature of:

20 °C

Additional information

Galden is a multi-constituent substance consisting of low molecular weight perfluoropolyethers (PFPE). Two grades of Galden LMW are manufactured (Galden HT55 and Galden HT70), which contain the same perfluorinated constituents and differ only in the relative concentration of the constituents.

As the two grades both contain only perfluorinated constituents (albeit in different relative concentrations), the solubility properties of both Galden grades are very similar. The log Kow= 5.58 therefore is representative for both grades.