Reaction mass of [[(2-hydroxyethyl)imino]bis(methylene)]bisphosphonic acid and Phosphonic acid, P-[(tetrahydro-2-hydroxy-2-oxido-4H-1,4,2-oxazaphosphorin-4-yl)methyl]-

Vapour pressure

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

vapour pressure

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

See attached QMRF/QPRF

Principles of method if other than guideline:

Estimation by MPBPVP program, USEPA/Syracuse Research, v1.40 (see attached QMRF and QPRF)

GLP compliance:

no

Type of method:

other: QSAR

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

0 Pa

A predicted vapour pressure value of 2.7E-09 Pa was determined HEBMP-H. This is an accepted calculation method supported by a limited amount of additional validation.

Conclusions:

A predicted vapour pressure value of 2.7E-09 Pa at 25°C was determined for HEBMP-H using a valid estimation method. The result is considered to be reliable.

Reference 2

Endpoint:

vapour pressure

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

See attached QMRF/QPRF

Principles of method if other than guideline:

Estimation by MPBPVP program, USEPA/Syracuse Research, v1.40 (see attached QMRF and QPRF)

GLP compliance:

no

Type of method:

other: QSAR

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

0 Pa

A predicted vapour pressure value of 5.5E-08 Pa was determined for HEBMP-cyclic. This is an accepted calculation method supported by a limited amount of additional validation.

Conclusions:

A predicted vapour pressure value of 5.5E-08 Pa at 25°C was determined for HEBMP-cyclic using a valid estimation method. The result is considered to be reliable.

Description of key information

Vapour pressure (HEBMP-H, linear): 2.7E-9 Pa at 25°C (QSAR)

Vapour pressure (HEBMP-H, cyclic): 5.5E-8 Pa at 25°C (QSAR)

Key value for chemical safety assessment

Vapour pressure:

0 Pa

at the temperature of:

25 °C

Additional information

Predicted vapour pressure values of 2.7E-9 Pa at 25°C and 5.5E-8 Pa at 25°C were obtained for the linear HEBMP-H and cyclic condensation product of HEBMP-H respectively using an accepted calculation method (MPBPVP program, USEPA/Syracuse Research, v1.43). The result (Fisk 2010) is considered to be reliable and are used as weight of evidence that the vapour pressure of the substance is very low. The impurities are phosphonates that are structurally similar to the main constituent; all will have negligible vapour pressure.

The predicted vapour pressure of the parent acid of HEBMP has been supported by a measured vapour pressure study for the sodium salt (HEBMP-xNa). A measured vapour pressure value of <0.0038 Pa at 25°C was determined for the equilibrium mixture of HEBMP-xNa using a vapour pressure balance method in accordance with OECD Test Guideline 104 and in compliance with GLP. The predicted value is used for the chemical safety assessment because it is not a limit value.