Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

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.