MICROBIAL DETERIORATION OF MATERIALS - CA SE-HISTORIES AND COUNTERMEASURES FOR PLASTICS AND ORGANIC AND NATURAL MATERIALS - MICROBIAL DETERIORATION OF PLASTICS

Large-scale production of synthetic plastics began in the thirties. Th e versatility of the new materials was enhanced by new processing tech nologies and above all by designing special formulations tailored to t he different fields of applications. Their increasing universal applic ation was, however, also accompanied by growing records of documented microbial attack. The mechanisms of attack have largely been identifie d. Damage is commonly caused by surface growth, discolourations and ch anges of mechanical and electrical properties. National and internatio nal test standards have been developed to predict the service life of certain plastics or to evaluate the protection afforded by certain bio cides. Several standard methods of test are presented and the criteria for evaluation are critically examined. Finally, the activities of th e Plastics Project Group are represented, wich has carried out several international co-operative tests to evaluate the reproducibility of t he results of different test methods and has worked out recommendation s and improvements.