7.3.2 Special Practices (in addition to those listed for ABSL2)

  • All procedures involving the manipulation of infectious materials, handling infected animals or the generation of aerosols must be conducted within a biosafety cabinet or other physical containment device when practical.  When a procedure cannot be performed within a biosafety cabinet, a combination of personal protective equipment and other containment devices must be used.  Consideration should be given to the use of restraint devices and practices that reduce the risk of exposure during animal manipulations (e.g., physical restraint devices, chemical restraint medications, etc).
  • The risk of infectious aerosols from infected animals or their bedding also can be reduced if animals are housed in containment caging systems (such as solid wall and bottom cages covered with filter bonnets, open cages placed in inward flow ventilated enclosures, HEPA-filter isolators and caging systems, or other equivalent primary containment systems).
  • Actively ventilated caging systems must be designed to prevent the escape of microorganisms from the cage.  Exhaust plenums for these systems should be sealed to prevent escape of microorganisms if the ventilation system becomes static, and the exhaust must be HEPA filtered.  Safety mechanisms should be in place that prevent the cages and exhaust plenums from becoming positive to the surrounding area should the exhaust fan fail.  The system should also be alarmed to indicate when operational malfunctions occur.
  • A method for decontaminating all infectious materials must be available within the facility; preferable within the areas where infectious materials and/or animals are housed or are manipulated (e.g. autoclave, chemical disinfection, or other approved decontamination methods).  Consideration should be given to means for decontaminating routine husbandry equipment, sensitive electronic and medical equipment.
  • Decontaminate all potentially infectious materials (including animal tissues, carcasses, contaminated bedding, unused feed, sharps, and other refuse) before removal from the areas where infectious materials and/or animals are housed or are manipulated by an appropriate method.  It is recommended that animal bedding and waste be decontaminated prior to manipulation and before removal from the areas where infectious materials and/or animals are housed or are manipulated, preferably within the caging system.
  • Develop and implement an appropriate waste disposal program in compliance with applicable institutional, local and state requirements.  Autoclaving of content prior to incineration is recommended.