A means to quantify just how a particular biohazard
should be handled in a laboratory environment.
BSL-1: Agent does not cause disease in humans. Wear gloves and a lab coat. Wash your hands before eating.
BSL-2: Agents of moderate potential hazard. Don't let random people in your lab. Be careful with contaminated sharps. Double bag your hands, lab coat, and face mask.
BSL-3: Agents may cause serious or potentially lethal disease via inhalation. Train your lab rats. Work in a safety cabinet. Pay attention to ventilation when designing your lab. Gloves, gown, and mask with a respirator.
BSL-4: Dangerous and exotic agents which pose a high individual risk of aerosol-transmitted laboratory infections and life-threatening disease. Work in a glovebox or in a safety cabinet while wearing a bunny suit. Shower after leaving lab. Autoclave lab clothing before washing it.