This document discusses biosafety and biosecurity when working with infectious agents in a laboratory setting. It defines biosafety as safety precautions that reduce risk of exposure and contamination. There are four biosafety levels depending on the agent, with level 4 being the most restrictive for dangerous pathogens with no treatment. Key equipment for containment includes biosafety cabinets, which use HEPA filters to circulate air and prevent exposure, with various types for different risk levels. Proper use and certification of this equipment is important for protecting laboratory workers and the public.