Laboratory workers who handle infectious materials in the microbiology laboratory should be aware of the work practices, safety equipment, and barriers that will protect them and others in the area from infectious agents.
The CDC and the National Institutes of Health (NIH) created guidelines to assist laboratories in developing safe practices based on the risk level of the infectious agents that are handled. These guidelines are referred to as Biosafety Levels (BSL) 1 through 4 (BSL-1 --> BSL-4). Each increasing number represents a laboratory's containment capabilities (e.g., single-pass air and negative pressure systems, BSCs, etc.) and requires more stringent work practice and increasingly protective safety equipment and barriers for the increased risk of working with higher consequence pathogens.
10. U.S. Department of Health and Human Services. Biosafety in Microbiological and Biomedical Laboratories. 6th ed. The Centers for Disease Control and Prevention (CDC). Revised June 2020. Accessed November 8, 2023. https://www.cdc.gov/labs/BMBL.html