This European Standard deals with all significant hazards, hazardous situations or hazardous events relevant to the design and construction of internal mixers for production and laboratory applications, when the machines are used as intended and under the conditions of misuse which are reasonably foreseeable by the manufacturer (see Annex A). An internal mixer begins at the feed openings and ends at the discharge opening. Internal mixers usually do not produce explosive atmospheres. Where materials are processed, which may cause an explosive atmosphere, the Directive 94/9/EC on the Equipment and protective systems intended for use in potentially explosive atmospheres (ATEX) should be applied. Explosion hazards are not dealt with in this document. The safety requirements for the design of exhaust systems and of ancillary equipment are not covered. The safety requirements for the interaction between internal mixers and ancillary equipment are covered. This European Standard is not applicable to internal mixers manufactured before the date of its publication.