No single measurement procedure is applicable to the entire range of vapour pressures from lessthan 10-10 to 105 Pa. Eight methods for measuring vapour pressure are included in this guideline which canbe applied in different vapour pressure ranges. The various methods are compared as to application andmeasuring range in Table 1. The methods can only be applied for compounds that do not decompose underthe condition of the test. In cases where the experimental methods cannot be applied due to technicalreasons, vapour pressure can also be estimated and a recommended estimation method is set out in theAnnex.