BSL-3 laboratories are used to study infectious agents or toxins that may be transmitted through the air and cause potentially lethal infections. Researchers perform all experiments in a biosafety cabinet. BSL-3 laboratories are designed to be easily decontaminated. As an additional safety measure, these laboratories must use controlled, or “directional,” air flow to ensure that air flows from non-laboratory areas (such as the hallway) into laboratory areas. Other engineered safety features include a requirement for entry through two self-closing, interlocked doors, sealed windows, floors and walls, and filtered ventilation systems. BSL-3 labs must also be equipped to decontaminate laboratory waste using an incinerator, an autoclave, and/or another method of decontamination, depending on the biological risk assessment.