Dioctanoyl peroxide

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 123 (Partition Coefficient (1-Octanol / Water), Slow-Stirring Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

slow-stirring method

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

Chemical name: Dioctanoyl peroxide
Trade name: Perkadox SE-8
CAS: 762-16-3
Batch/Lot no.: 1204350050
Purity: 99.2%
Composition: see CoA
Appearance: White flakes
Expiry date: January 18, 2016
Storage: - 20°C

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

> 6.5

Temp.:

25 °C

Remarks on result:

other: pH not noted

Details on results:

The concentration of test substance in the 1-octanol and water phase was analysed after 24 hours. The log Pow values of the replicates were calculated using the final concentrations. The average log Pow value for the test substance was calculated to be >6.5. The observed partition coefficient showed that the test substance dissolved well in 1-octanol and almost not in water. The concentration of the test substance solution at the end of the test deviated only 5.1% from the concentration determined at the beginning of the test. Therefore the stability of the test substance solutions was acceptable for the course of the test.

Results of definitive test

Octanol phase

Water phase

Replicate

meas. conc.

dilution

final conc.

meas. conc.

dilution

final conc.

Pow

log Pow

mg/L

factor

µg/L

µg/L

factor

µg/L

1

30173

1

30173473

<LOQ*

1

<

10

>

3.0.E+06

>

6.5

2

29509

1

29509337

<LOQ*

1

<

10

>

3.0.E+06

>

6.5

3

31283

1

31282592

<LOQ*

1

<

10

>

3.1.E+06

>

6.5

*LOQ = 10 µg/L

Average

>

3.0.E+06

>

6.5

St. dev.

0.013

Stability test substance solution

Date	Time point	Concentration	Deviation
	hr	mg/L	(24 to 0 hr)
29-7-2015	0	31255
30-7-2015	24	29672	-5.1

Conclusions:

The average log Pow value for the test substance was calculated to be >6.5. The observed partition coefficient showed that the test substance dissolved well in 1-octanol and almost not in water.

Executive summary:

The purpose of this study was to determine the partition coefficient n-octanol/water of thetest substanceusing the slow-stirring method, complying with the OECD Guideline No. 123.

The averaged measured log P_owvalue for dioctanoyl peroxide, as determined from the test, was >6.5. Therefore dioctanoyl peroxide had a P_owvalue of >3.0E+06.

Description of key information

log Kow is > 6.5 @ 25 oC

Key value for chemical safety assessment

Log Kow (Log Pow):

6.5

at the temperature of:

25 °C