We are very familiar with the kind of harm that certain organisms can cause. Our continuous struggle against diseases that affect man, animals and plants illustrates the evolutionary power of biological agents. As a consequence known pathogens have been characterized and precaution is prescribed when being obliged to handle them, e.g., for research or clinical objectives. In these cases the effects of exposure are clearly understood and there is experience in handling them.
With the development of biotechnology more organisms are identified and applied in research, development and commerce. In many cases, little or no information is available on their pathogenicity. Whereas most of them present only minor safety challenges, some reveal themselves to be opportunistic pathogens or to cause Laboratory Acquired Infections. The absence of a full understanding of the potential pathogenic behaviour is the main challenge to be addressed in determining a safe way to handle these organisms.
In addition, certain organisms are considered emerging pathogens. While the complete evolving pathogenic behaviour may not be established, there are already important indications. In such a case both the known and the potential pathogenicity have to be taken into account.
