This document specifies the continuous drop test apparatus and associated test method for the reproducible production of dust from a bulk material under standard conditions, and the measurement of the inhalable and respirable dustiness mass fractions, with reference to existing documents, where relevant (see Clause 6). The continuous drop method intends to simulate dust generation processes where there are continuous falling operations (conveying, discharging, filling, refilling, weighing, sacking, metering, loading, unloading etc.) and where dust is liberated by winnowing during falling. It can be modified to measure the thoracic fraction as well, but this modification is not described in this document. It differs from the rotating drum method presented in EN 15051-2 [4] in that in this document, the bulk material is dropped only once, but continuously, while in EN 15051-2, the same bulk material is repeatedly dropped. Furthermore, this document specifies the environmental conditions, the sample handling and analytical procedures and the method of calculating and presenting the results. A categorization scheme for dustiness is specified, to provide a standardized way to express and communicate the results to users of the bulk materials. This document is applicable to powdered, granular or pelletised bulk materials. This document is not applicable to test the dust released when solid bulk materials are mechanically treated (e.g. cut, crushed).