When designing a BE facility with mixed chemical and biological hazards, which approach best describes the ventilation strategy selection?

• A. Conduct hazard assessment, identify contaminant sources, determine air change requirements, select LEV and general ventilation strategies, and incorporate containment where necessary
• B. Install LEV at every workstation without a prior assessment
• C. Rely solely on PPE and ignore ventilation
• D. Use only general ventilation with no containment

Answer: (A)

The main idea is to design ventilation based on a thorough understanding of the hazards and where they come from, then choose controls that address those sources while protecting workers. In a facility with mixed chemical and biological hazards, you don’t rely on a single solution—you blend source-capure ventilation with dilution ventilation and use containment where needed.

Start with a hazard assessment to map out what contaminants are present, where they originate, how they could spread, and what exposure limits apply. From there, determine how many air changes are needed to keep airborne concentrations within safe levels, and decide where to apply local exhaust ventilation at the source versus relying on general ventilation to dilute remaining air. If certain processes generate difficult-to-control emissions or biological aerosols, use containment measures—such as sealed enclosures or containment cabinets—to prevent releases from occurring in the room.

This approach directly tackles both chemical vapors and biological aerosols by capturing contaminants at the source when possible, while providing overall air mixing and removal through general ventilation, and by physically containing high-risk operations. It minimizes reliance on PPE and gives a robust, engineering-based control scheme.

Other approaches fall short because they skip essential steps or rely on a single tactic. Installing LEV at every workstation without assessing the actual hazards can lead to over- or under-design and gaps in protection. Relying only on PPE ignores airborne transmission and exposure potential. Using only general ventilation without containment or source control often fails to keep concentrations below safe levels for hazardous activities.