There are four biosafety levels. Each level has specific controls for containment of microorganisms. The primary risks that determine levels of containment are infectivity, severity of disease, transmissibility, and the nature of the work conducted.

BSL 1 Not known to consistently cause disease in adult humans and of minimal potential hazard to facility personnel and the environment.
Examples=skin bacteria and yeast
BSL 2 Moderate potential hazard to personnel and the environment. Includes bacteria and viruses that cause only mild disease to humans or are difficult to contract via aerosol in the lab setting.
Examples=pathogenic strains of E. coli, Staphylococcus, Salmonella, Plasmodium falciparum, Toxoplasma, and herpes simplex viruses
BSL 3 Microbes can be either indigenous or exotic and they can cause serious or potentially lethal disease through respiratory transmission.
Examples=human immunodeficiency virus, swine flu, Yersinia pestis, Mycobacterium tuberculosis, West Nile virus, rabies virus
BSL 4 Dangerous and exotic, posing a high risk of aerosol transmitted infections. Infections caused by these microbes are frequently fatal and without treatment or vaccine.
Examples=Ebola virus, smallpox virus


Alcaligenes faecalis ATTC 8750 1
Aspergillus niger  Fisher S07205ND 1
Bacillus subtilis subsp. spizizenii ATTC 6633 1
Clostridium sporogenes ATTC 19404 1
Enterococcus faecalis  ATTC 19433 2
Escherichia coli ATTC 25922 1
Escherichia coli 10-beta competent high efficiency New England BioLabs C30191 1
Klebsiella aerogenes ATTC13048 1
Klebsiella pneumoniae ATTC 33495 2
Micrococcus luteus ATTC 10240 1
Micrococcus roseus ATTC 186 1
Mycobacterium smegmatis ATTC 14468 1
Neiserria sicca ATTC 29193 1
Penicillium italicum Fisher S07242ND 1
Proteus mirabilis ATTC 35659 2
Pesudomonas aeruginosa ATTC 25619 2
Rhizopus stolonifer Fisher S07207ND 1
Saccharomyces cerevisiae Store bought 1
Staphylococcus aureus ATTC 25923 2
Staphylococcus epidermidis  ATTC 12228 1
Streptococcus Group C ATTC 9528 2
Streptococcus pneumoniae ATTC 6303 2
Streptococcus sanguinis  ATTC 10556 2
T4 Bacteriophage  Carolina Biological 12-4330 1



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Laboratory Exercises in Microbiology Copyright © 2022 by Anne Mason M.S. and Jill Raymond Ph.D. is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, except where otherwise noted.

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