Chemical antimicrobial agents biocides

Resistance to antimicrobial agents is of concern as it is well known that bacterial resistance to antibiotics can develop. Many bacteria already derive some nonspecific resistance to biocides through morphological features such as thek cell wall. Bacterial populations present as part of a biofilm have achieved additional resistance owkig to the more complex and thicker nature of the biofilm. A system contaminated with a biofilm population can requke several orders of magnitude more chlorine to achieve control than unassociated bacteria of the same species. A second type of resistance is attributed to chemical deactivation of the biocide. This deactivation resistance to the strong oxidising biocides probably will not occur (27). 

Dried organic deposits m inhibit penetration of the chemical agent. Where possible, objects to be disinfected should be thoroughly cleaned. The presence of ions in water can also affect activity of antimicrobial agents, thus water for testing biocidal activity can be made artifieially hard by addition of ions. 

In both the USA and Europe, the decision was taken on a political level to make use of antimicrobial agents subject to statutory requirements. The European Parliament and Council directive 98/8/EC concerning the marketing of biocidal products came into force on 16 February 1998 (EC, 1998) the Biocidal Products Directive . This directive encompasses general descriptions of the products, physio-chemical, toxicological and ecotoxicological tests as well as additional biological and biochemical checks. The transition period allowed for national implementation of the provisions expired in February 2000. 

Schindley, B. E. Pricker, C. M. Grignol, G. E. Single-use decontamination package and antimicrobial system with flow-through chemical indicator for measurement of biocidal agents. PCX Int. Appl. WO 2000069475, 2000 Chem. Abstr. 2000,134, 21519. 

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