Registration Dossier

Diss Factsheets

Physical & Chemical properties

Endpoint summary

Administrative data

Description of key information

Additional information

The chemical structure of Tetraphenyl p-phenylene diphosphate (SOL-DP) contains hydroquinone moiety and phenylphosphate moieties. The empirical formula is C30H24O8P2.

SOL-DP is used as a flame retardant for the plastics industry. It has a solid phase retardation mechanism. Upon exposure to flame SOL-DP produces a glassy layer which separate between the flame and the fuel source.

SOL-DP is in solid phase at room temperature. The particle size distribution of the solid indicates a wide distribution from 1 micrometer to 400 micrometer. The substance has a negligible vapor pressure (0.00001 Pa at 25oC) and a melting point below 110oC. During the extrusion process the substance melts and thus is homogenously spreads and mixed in the plastic matrix. The decomposition process (5% at 326oC) takes place before boiling can be detected.

The substance is hydrophobic and insoluble in water as indicated by the water solubility value of 1.87*10-5mg/l.