This guideline is a revised version

This guideline is a revised version of the original Guideline 104 which was initially adopted in1981 and subsequently updated in 1995. One additional method, Effusion method: isothermalthermogravimetry, is included in this version. The original guideline was developed based on the ECmethod “Vapour Pressure” published in 1992 (1) and in 2001 an additional method designed for chemicalswith very low pressures (down to 10-10 Pa) was proposed by BASF. In the light of needs for methodsespecially in relation to obtain vapour pressure for substances with low vapour pressure, other methods ofthis guideline are re-evaluated with respect to other applicability ranges