Registration Dossier

Physical & Chemical properties

Particle size distribution (Granulometry)

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

The endpoint is not relevant to substances not used or marketed in a non-solid form.

Additional information

The substance is marketed and used in a non-solid form (aqueous solution). Therefore, testing for granulometry is waived in accordance with Column 2 of REACH Annex VII.

In solution, HEBMP-H (CAS 5995-42-6) undergoes a reversible internal condensation reaction to form a pH-dependent equilibrium mixture with the cyclised structure 4-(Phosphonomethyl)-2-hydroxy-2-oxo-1,4,2-oxaza-phosphorinane (CAS 32422-02-9, c-HEBMP) and water. The precise proportion of the two forms is dependent on pH, temperature and time, and under acidic or neutral conditions, the proportion of c-HEBMP in the multi-constituent substance may reach proportions as high as ≥ 50% w/w. Spectroscopic evidence from 31P-NMR analysis suggests that in the pH range ca. 1 – 7 a high proportion (50-75% w/w) is present as the cyclised form. The two forms exist in equilibrium therefore it is extremely difficult to separate and purify both forms.