Registration Dossier

Physical & Chemical properties

Endpoint summary

Administrative data

Description of key information

Appearance/physical state/colour:

The substance is a colourless and odourless crystalline solid powder at room temperature. Substance is hygrosopic and sensitive to water and humid air.

(Source: internal company data)

Melting point:

Two studies were performed with Pyromellitic dianhydride (PMDA) and the hydrolysis product Pyromellitic acid (PMA):

the melting point of PMDA and PMA were both found to be 286°C (559 K), decomposition was noted starting at approx. 210°C. The data generated during the determination supported the Sponsor's information that the test material decomposed on heating to generate the anhydride. In a supporting study similar or equivalent to OECD no. 102, the melting point was determined 286°C.

(Source: GLP-report & literature)

Boiling point:

Two studies were performed with Pyromellitic dianhydride (PMDA) and the hydrolysis product Pyromellitic acid (PMA):

the boiling point of PMDA and PMA were both found to be > 400°C (673 K). In a supporting study similar or equivalent to OECD no. 103, the boiling point was determined to be 397-400°C.

(Source: GLP-report & literature)

Density:

The density as reported in literature is 1.68 g/cm3 at 20°C.

(Source: Literature data)

Particle size distribution:

The particle size distribution of the test item was found to be [125 μm; 1000 μm]. Less than 10% of the test item is larger than 1 mm and more than 90% is larger than 125 μm.

(Source: GLP-report)

Vapor pressure:

Two studies were performed with Pyromellitic dianhydride (PMDA) and the hydrolysis product Pyromellitic acid (PMA):

the vapour pressure of PMDA was determined to be 2.8 × 10 Exp.-6 Pa at 25°C, whereas the vapour pressure of PMA was found to be 6.3 × 10 Exp.-7 Pa at 25°C. In a supporting study similar or equivalent to OECD no. 104, the vapor pressure was found to be 30 mm Hg at 305°C.

(Source: GLP-report & literature)

Partition coefficient n-octanol/water:

As the substance to be registered, PMDA, is unstable in water, the corresponding hydrolysis product Pyromellitic acid (PMA) was tested.

The partition coefficient of the test material has been determined to be log Pow <= -2.03. In addition, the partition coefficient log Pow for PMDA itself was estimated to be 2.14 at 20 °C (calculated by Kowwin vl. 67, EPI suite v3.11).

(Source. GLP-report & calculation)

Water solubility:

As the substance to be registered, PMDA, is unstable in water, the corresponding hydrolysis product Pyromellitic acid (PMA) was tested.

The water solubility was determined to be 8.56 g/L at 20°C. The pH value was 8.56. In addition, the water solubility for PMDA itself was calculatedto be 519 mg/L at 20°C (calculated; EPI suite v3.11).

(Source: GLP-report)

Surface tension of an aqueous solution:

Test not performed; as the substance to be registered, PMDA, is unstable in water (fast hydrolysis), the surface tension of an aqueous solution can not be measured. The surface tension of an aqeous solution of the hydrolysis product Pyromellitic acid PMA as reported in literature is 114 mN.

(Source: Expert assessment & literature)

Flash point:

Test not performed; the study does not need to be conducted because the flash point is only relevant to liquids and low melting points solids.

(Source: Expert assessment)

Auto flammability:

No self-heating was observed up to a maximum temperature of 400°C, therefore relative self-ignition temperature was considered to be > 400°C.

(Source: GLP-report)

 

Flammability:

In the preliminary test the test item could not ignited. Based on the results of the preliminary test, no main test was performed. In addition, tests A.12 and A.13 were not conducted, as based on the chemical structure, the test item does neither react with water nor evolve any flammable gases in contact with (humid) air. Therefore, the test item was considered to be not flammable.

(Source: GLP-report and expert assessment)

Explosiveness:

Based on chemical structure and information on handling and use the substance was considered non-explosive. Experimental determination was waived.

(Source: Expert assessment)

Oxidizing properties:

From the assessment of the chemical structure it was established that the test substance would not have oxidizing properties.

(Source: Expert assessment)

Additional information