MEASUREMENTS OF MINIMUM STERILIZATION TIM ES IN CONTINUOUSLY OPERATING PLANTS FOR ANIMAL WASTE PROCESSING

The increasing number of new insights into the mechanisms of triggers and ways of infection of BSE and the resulting conditions for a reliab le inactivation of the causative agent have given new impetus to the d iscussion of sterilization conditions in the field of animal waste pro cessing, in particular in continuously operating plants. To guarantee and to control the required sterilization conditions has thus become m ore important than ever. This report is on measurements of residence t imes in the sterilizer of a continuously operating animal waste proces sing plant. The radiotracer method was applied which allows to determi ne the actual residence time of the material under sterilization condi tions and thus goes beyond the possibilites of the residence time test s that are recommended in the appendix of the decision of the Commissi on of the European Communities/EU Commission of 27 June 1994 (94/382/E C, Official Journal of the EC No. L 172/25-28 of 7 July 94). It could be shown that the minimum heating time of 20 min. at a temperature of 133 degrees C and a pressure of 3 bar as prescribed in the German regu lation for animal waste processing plants of 1st September 1976 (BGBl. I p. 2588) is observed for the entire material under normal operating conditions.