Biological Risk Assessment and Risk Management
Risk assessment is the foundation on which every other biosafety decision rests. A candidate must be able to walk through the core steps: identify the agent and its inherent hazards (pathogenicity, infectious dose, route of transmission, availability of treatment or vaccine, environmental stability, host range), characterize the activity (volume, concentration, aerosol potential, procedures such as centrifugation, pipetting, and animal work), and then assign a risk group and a corresponding biosafety level. Understand the distinction between risk group (a property of the agent, ranked 1–4) and biosafety level (a property of the facility and practices chosen for the work). A risk group 3 agent handled in a way that generates no aerosols may, in some jurisdictions, be worked with under modified BSL-3 or enhanced BSL-2 conditions - the assessment, not the agent label alone, drives the controls.
Traps in questions: confusing risk group with biosafety level; forgetting that risk assessment is iterative and must be repeated when procedures, agent, or personnel change; treating a single control (e.g., a biosafety cabinet) as sufficient when the principle is layered controls (engineering, administrative, PPE). Also watch for the "worst-case" framing - assessment should reflect realistic exposure scenarios, not hypothetical extremes.
Rule of thumb: assess the combination of agent, procedure, and host. A low-risk agent in a high-aerosol procedure can warrant higher containment than a high-risk agent handled exclusively in a sealed system.
Worked example: A lab plans to culture a Risk Group 2 bacterium in large volumes with vortexing and open centrifugation. Although the agent is RG2, the aerosol-generating steps push the assessment toward BSL-2 with a biosafety cabinet and sealed centrifuge cups, and the risk assessment document should record that reasoning.