Use of biocides - toxicological effects versus microbiological efficacy

The use of biocidal products is regulated in the European Union based on the biocidal products directive 98/8/EC (BPD) and the biocidal products regulation (BPR). By definition biocidal products are "preparations intended to destroy, render harmless, prevent the action of, or otherwise exert a controlling effect on any harmful organism by chemical or biological means". This already includes a toxic action which should ideally be directed only against the target organisms (e.g. bacteria) and not against humans and the environment. Since the actual effect depends on specific use concentrations, several endpoints have to be addressed for final evaluation: * Testing of biocidal efficacy * DBL Risk assessment for humans (consumer and worker) and the environment. Whereas the requirements for toxicological studies used for risk assessment are well known and defined, this is not given for all efficacy studies. Here different study requirements are based on the specific application, which would include different matrices (e.g. cooling liquids), residence times and a varying spectrum of pathogenic microorganisms. (Table see in PDF-File) Especially in the area of disinfection (hygiene, hospital) the requirements for efficacy testing are well established and the benefit of biocidal use is evidenced. In the area of preservation the testing methods are not yet standardized. Many biocides are therefore not tested according to comparable conditions and the effective use concentration is difficult to derive. In consequence this might lead to ambiguous results and hence to a possibly overestimation in risk assessment. However, generally a risk-benefit analysis would be desirable for products, especially for those which display unique properties (essential use) in preventing infectious diseases in humans evoked by pathogenic microorganism and/or bacterial toxins. In summary for the evaluation of biocides the testing guidance's regarding microbial efficacy have to be further developed. Additionally guidance's on risk-benefit analysis would help to ensure a justified use of biocides.