Which of the following is an example of a primary barrier in a laboratory?

A biological safety cabinet serves as a primary barrier in a laboratory because it is specifically designed to protect the user, the laboratory environment, and the product being worked on from contamination. These cabinets provide a physical barrier that isolates the work area and employs high-efficiency particulate air (HEPA) filters to capture particulates, including pathogens. This ensures that any aerosols or particulates generated during procedures are contained within the cabinet, significantly reducing the risk of exposure to harmful biological agents.

While air locks, shower areas, and ultraviolet lighting contribute to laboratory safety and decontamination protocols, they do not act as primary barriers. Air locks help manage access to restricted areas, shower areas are meant for personal decontamination, and ultraviolet lighting can be used for disinfection but does not provide a direct containment mechanism during active work with hazardous materials. This distinction underscores the role of biological safety cabinets as essential tools for maintaining a controlled and safe working environment in laboratories that handle biological materials.