This part of the European Standard specifies a method for determining the flowability, as defined in CEN/TR 15463 [1], of sludge by means of the extrusion tube apparatus. This part of this European standard is applicable to sludge and sludge suspensions from: - storm water handling; - urban wastewater collecting systems; - urban wastewater treatment plants; - plants treating industrial wastewater similar to urban wastewater (as defined in Directive 91/271/EEC); - water supply treatment plants. This method is also applicable to sludge and sludge suspensions of other origins.