A method and device in which exhaust fluid from a facility or equipment for treating biologically active material is heated to a temperature at least sufficient to kill or denature hazardous agents, and conveyed through a filter which is heated, preferably by the fluid, to essentially the same temperature. The relevant temperature is maintained during operation in both the fluid and the filter. Since the filter is dimensioned to trap microbial agents like bacteria and viruses and the temperature of the filter surfaces is sufficient for sterilization, microbial agents are bound to come into contact with said surfaces and a very high degree of sterilization certainty is reached.
