This document discusses infection control precautions in the emergency department (ED). It differentiates between standard precautions, which apply to all patients, and transmission-based precautions, which include contact precautions for infections spread through physical touch, droplet precautions for those requiring close proximity, and airborne precautions for infections that can remain suspended in the air. Special rooms, equipment, and personal protective equipment are required depending on the precaution type. Failure to properly implement precautions can result in exposure to infections and necessitate contact tracing of patients and staff.