Final answer:
Under COSHH regulations, biological agents are categorized into four biological safety levels (BSLs) based on their risk to health. BSL-2 covers agents that pose moderate risk and require precautions such as restricted access, PPE, and the use of biological safety cabinets. Agents are classified according to factors such as infectivity, transmission, and potential severity.
Step-by-step explanation:
The categories of exposure to biological agents under the Control of Substances Hazardous to Health (COSHH) Regulations are typically aligned with the biological safety levels (BSLs) defined by the Centers for Disease Control and Prevention (CDC). These BSLs are categorized based on factors such as the agent's infectivity, ease of transmission, potential disease severity, and the type of work being performed with the agent. The CDC recognizes four biosafety levels:
- BSL-1: Agents not known to consistently cause disease in healthy adults.
- BSL-2: Agents that pose moderate risk to laboratory workers and the community, such as Staphylococcus aureus and Salmonella spp.
- BSL-3: Agents that may cause serious or potentially lethal diseases via inhalation and require more stringent controls.
- BSL-4: Dangerous exotic agents which pose a high risk of life-threatening disease, for which there may be no available vaccine or treatment.
In a BSL-2 setting, precautions include restricted access, proper personal protective equipment (PPE), use of biological safety cabinets for aerosol-generating processes, and facilities equipped with self-closing doors and an autoclave to sterilize materials.