Classes B and C medical waste is of particular concern since it is an epidemiological and toxicological hazard. Predisinfection of Class B medical waste with the chemicals that have different toxicity levels, as well as further burial in the urban landfill were a reason for defining its hazard classes by biotesting in order to establish the possibility of additional environmental pollution. Class B (epidemiologically hazardous) medical waste was ascertained to be little dangerous and indangerous to the environment. The findings show it necessary to develop an integral waste hazard index that would reflect the whole spectrum of its negative impact on the environment and human health.