As the table below demonstrates, different microorganisms require different containment facilities and processes to ensure safe handling. There are probably tens of thousands of laboratories in the United States that handle BSL1 and BSL2 microorganisms. There are over a thousand U.S. laboratories registered with USDA as BSL3, and only 15 laboratories in the U.S. that handle BLS4 microorganisms.
For the companies that make disinfectants and antimicrobial medical devices, testing with BSL3 or BSL4 pathogens is rarely warranted: EPA and FDA have identified suitable surrogates that can be safely handled by ordinary microbiology laboratories. For instance, Mycobacterium bovis – which is BSL2 – can be used as a surrogate for Mycobacterium tuberculosis for disinfectant registrations and 510k applications.