Dioctanoyl peroxide

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

April to June 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: ASTM E1782-08

Deviations:

no

Principles of method if other than guideline:

Thermal analysis.

This test method is neither included into EC Regulation 761/2009, Guideline A.4 Vapour
Pressure [8.5], nor into OECD Guideline 104 Vapour pressure [8.6]. Nevertheless, this method
was taken because for substances which are thermally unstable and contain impurities it is a
more suitable method than the other listed in the above-mentioned guidelines. It is expected that
this method will be included into EC Guideline A.4 in the near future.

GLP compliance:

no

Other quality assurance:

other: ISO 9001

Type of method:

other: Thermal analysis

Key result

Test no.:

#1

Temp.:

20 °C

Vapour pressure:

0.1 Pa

Remarks on result:

other: extrapolated using Antoine equation derived from higher temperature data

The first DSC test at reduced pressure was performed at 5 mBar; no endothermic effect was

observed till 70°C. This pressure is around the lower pressure borderline of the DSC investigations.

Observations:

- no endothermic effect due to evaporation till a sample temperature of 80°C

- exothermic decomposition effect observed in this high rate scan at 70°C

- a decomposition gas / liquid flow was obtained, that result in a mass loss of around 25%

- part of the escaped sample was on the DSC sensor as a liquid.

Based on this observation one can conclude that the vapor pressure of the test sample is

below 0.285 mBar or below 0.0285 kPa at 80°C.

Note: The temperature of 80°C is very high for the test substance. Handling at this

conditions is only possible for very small samples in a DSC scan with a relative high

heating rate; 5°C/min. in this test.

Additional calculations and comparisons are performed to make a better estimation of the

vapor pressure of the test substance at room temperature.

So, the vapor pressure of two anhydrides is compared with the vapor pressure of the

corresponding peroxides. This is done for:

- Tx 187-pure = isobutyric peranhydride and isobutyric anhydride and

- Laurox = lauroyl peranhydride and lauroyl anhydride.

Based on the comparison we conclude that the vapor pressure of the test substance is

around 5*10-5 mBar.

In other words, the vapour pressure is below the REACH borderline for occupational safety

of 0.0001 kPa or below 0.001 mBar at 20°C.

Conclusions:

The vapour pressure of the test substance was determined according to EC Regulation [8.5] and according to the OECD Guideline [8.6].
The vapour pressure of dioctanoyl peroxide is below 0.1 Pa or below 0.001 mBar at 20°C.

Executive summary:

The vapour pressure of the test substance was determined according to EC Regulation [8.5] and according to the OECD Guideline [8.6].

The vapour pressure of dioctanoyl peroxide is below 0.1 Pa or below 0.001 mBar at 20°C.

Description of key information

The vapour pressure of the test substance was determined according to EC Regulation [8.5] and according to the OECD Guideline [8.6].

The vapour pressure of dioctanoyl peroxide is below 0.1 Pa or below 0.001 mBar at 20°C.

Key value for chemical safety assessment

Vapour pressure:

0.1 Pa

at the temperature of:

20 °C