CentralNotice Biosafety level From Wikipedia, the free encyclopedia Jump to: navigation , search This article's factual accuracy may be compromised due to out-of-date information . Please update this article to reflect recent events or newly available information. (May 2013) A biosafety level is the level of the biocontainment precautions required to isolate dangerous biological agents in an enclosed facility. The levels of containment range from the lowest biosafety level 1 (BSL-1) to the highest at level 4 (BSL-4). In the United States, the Centers for Disease Control and Prevention (CDC) have specified these levels. [ 1 ] In the European Union , the same biosafety levels are defined in a directive . [ 2 ] 1 History 2 Rationale 3 Levels 3.1 Biosafety level 1 3.2 Biosafety level 2 3.3 Biosafety level 3 3.4 Biosafety level 4 4 List of BSL-4 facili...