This document specifies requirements for the evaluation of measuring procedures using samplers for the determination of a chemical agent present in the workplace atmosphere as a mixture of airborne particles and vapours. The procedures given in this document provide results only for the sum of airborne particles and vapours. The concentration is calculated in terms of mass per unit volume. NOTE Examples of substances which can be present in multiple phases are toluene diisocyanate, diethanolamine, ethyleneglycol or tributhylphosphate. This document can also be applied to complex mixtures, such as metal working fluids or bitumen fumes. This document is applicable to samplers and measuring procedures using these samplers in which sampling and analysis are carried out in separate stages.