Registration Dossier

Physical & Chemical properties

Endpoint summary

Administrative data

Description of key information

Additional information

Appearance:

Cyclohexylidenebis[tert-butyl] peroxide) is a colourless organic liquid at 20 °C and 1013 hPa.

Melting point:

The melting / freezing point study was waived according to column 2 of REACH Annex VII section 7.1 as the freezing point of 1,1-bis (tert-butylperoxy) cyclohexane is expected to be lower than -20°C. This temperature evaluation was based on a study that examined the stability of the substance to coldness, showing no crystallization at -25°C. Therefore an freezing temperature below -25°C is expected.

Boiling point:

Cyclohexylidenebis[tert-butyl] peroxide decomposes before boiling. Self-Accerelating Decomposition Temperature (SADT) of the substances is 60 °C (reference SADT: CLP regulations 2.15.2.3 and UN Recommendations on the Transport of Dangerous Goods, Manual of Tests and Criteria, 5th revised edition, sub-sections 28.1, 28.2, 28.3 and Table 28.3.)

Density:

Using the pycnometer method, the density of 1,1-Di-(tert-butylperoxy) cyclohexan 80 % in isododecane was determined to be 0.884 g/cm³ at 20 ± 0.2 °C.

Particle size distribution

Test method is only applicable for solids.

Vapour pressure:

At temperatures between 58°C to 100°C vapour pressures between 0.92 to 11.4 mBar were measured for 1,1-bis(tert-butylperoxy)cyclohexane.

Partition coefficient:

The partition coefficient (n-octanol/water) of ter-butyl peroxy cyclohexan was determined to be log Pow value 7.2 using the HPLC methode.

Water Solubility

The water solubility cyclohexylidenebis[tert-butyl] peroxide was estimated to be < 1 mg/L (quantification limit analytical method, HPLC-UV) at 20 °C +/- 0.5 °C. Thus, the substance was considered to be slightly soluble or insoluble.

Surface tension

Surface activity is not the desired property of the substance and moreover based on the chemical structure of cyclohexylidenebis[tert-butyl] peroxidewill not have surface activity.

Flash point:

Cyclohexylidenebis[tert-butyl] peroxide decomposes before the flashpoint is reached. Self-Accerelating Decomposition Temperature (SADT) of the substance is 60°C (reference SADT: CLP regulations 2.15.2.3 and UN Recommendations on the Transport of Dangerous Goods, Manual of Tests and Criteria, 5th revised edition, sub-sections 28.1, 28.2, 28.3 and Table 28.3.) See also ECHA guidance on the application of the CLP criteria, section 2.14.

Auto flammability

Test method is not applicable because substance decomposes under test conditions. Self-Accelerating Decomposition Temperature (SADT) of the TBPIB is 30 C (reference SADT: CLP regulations 2.15.2.3 and UN Recommendations on the Transport of Dangerous Goods, Manual of Tests and Criteria, 5th revised edition, sub-sections 28.1, 28.2, 28.3 and Table 28.3.) See also ECHA guidance on the application of the CLP criteria, section 2.14.

Flammability

Tests for flammability, flammability in contact with water and pyrophoric properties were waived as no such properties are expected for cyclohexylidenebis (tert-butyl) peroxide.

Explosiveness:

Substance has explosive properties because it is classified as Organic Peroxide Type B (reference CLP regulations 2.15.1.2, 2.15.2.2 and UN Recommendations on the Transport of Dangerous Goods, 16th revised edition, Section 2.5.3.2.4). See also ECHA guidance on the application of the CLP criteria, section 2.14.

Oxidizing properties:

Test is not applicable for organic peroxides. In the CLP regulations Organic peroxides are not oxidizers. They are classified in a distinct hazard class See also ECHA guidance on the application of the CLP criteria, section 2.14

Viscosity:

The dynamic viscosity of 1,1-Di-(tert-butylperoxy)cyclohexane 80% in Isododecane was examined by an Ubbelohde viscometer in three seperate measurements at 20°C. An average of the measrued processing times was considered for the viscosity calculation. The dynamic viscosity of the test substance is 4.4 mPas at 20°C. (BAM, 2011)