This European Standard specifies all significant hazards, hazardous situations and events relevant to all types of screw extruders for plastics and rubber, when they are used as intended and under conditions of misuse which are foreseeable by the manufacturer (see Clause 4). This European Standard additionally covers the following feeding systems: - hoppers; - single roller feed; - double roller feed; - crammer feeder; and the following ancillary equipment which form part of or are attached to the extruder: - screen changers; - melt/gear pumps; - melt pipes and adaptors; - static mixers; - extruder head that give initial shape to the extruded material. NOTE Metering devices are not covered by this standard. This European Standard does not deal with hazards caused by the processing of materials and which may lead to a risk of fire or release of health hazardous materials. An extruder conforming to this document is not regarded as a pressure vessel as defined in the Pressure Equipment Directive 97/23/EC. Extruders usually do not produce explosive atmospheres. Where materials are processed, which may cause an explosive atmosphere, the Directive 94/9/EC on the Equipment intended for use in Potentially Explosive Atmospheres (ATEX) should be applied. Explosion hazards are not dealt with in this document. This European Standard is not applicable to extruders which are manufactured before the date of its publication as EN.