Trilead dioxide phosphonate

Vapour pressure

Administrative data

Endpoint:

vapour pressure

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING

An experimental measurement can be omitted since the vapour pressure is expected to be < 10-5 Pa.

The vapour pressure of a substance is defined as the saturation pressure above a solid or liquid substance. Several different measuring methods are listed for the measurement of the vapour pressure of solids and liquids. However, the vapour pressure does not need to be measured due if calculations indicate that the value is significantly less than 10-5 Pa (appendix to EU A.4 and OECD 104).

Dibasic lead phosphite is a solid inorganic substance which decomposes at ~230 °C. In view of this, the vapour pressure of this substance can therefore be safely assumed to be negligible, i.e. below the level of significance (10-5 Pa).

For purposes of comparison, the vapour pressure of the phosphonate dianion (CAS 15477-76-6) was estimated using EPISUITE V4.11, yielding a vapour pressure of 6.06 * 10-11 mmHg at 25°C (Modified Grain method)(MPBPWIN v1.43). In consideration of the “salt” nature of Dibasic lead phosphite it can therefore be anticipated that the vapour pressure of this compound is well below the value for the phosphonate dianion and thus negligible.

Study waived in accordance with Annex XI, Section 1.