Biological Safety in the Experimental Tuberculosis Laboratory

This chapter provides scientists and technicians a basic orientation to health and safety practices appropriate for the control of hazards associated with the handling of Mycobacterium tuberculosis in the research laboratory. The most important message in this chapter is that M. tuberculosis should be handled only by those who have mastered basic safe practices. The laboratory in which this work is carried out has certain design and operational features that provide protection from exposure to M. tuberculosis for those other facility occupants who do not require access to the laboratory. The chapter discusses the importance of safety considerations and precautions that will help the user understand both the limitations and the benefits of this equipment. In the class I cabinet, the intake airflow passes through the work space of the cabinet. Class II cabinets can protect experimental materials from airborne contamination. Airborne contamination within the room air is prevented from reaching the work space by the downward airflow of high-efficiency particulate air (HEPA)-filtered air, which is supplied at the top of the cabinet's interior work space. Biological spills outside biological safety cabinets generate aerosols that can be dispersed in the air throughout the laboratory. A symptom check should be provided by a physician for all exposed individuals who were previously tuberculin positive. It is imperative that the tuberculin skin test always be placed and interpreted by an expert.