Table 1 Biosafety breakdown | Some of the differences between the four levels of biosafety laboratories

Use

For studying microbes that don’t consistently cause disease

For studying moderately hazardous microbes

For studying potentially lethal, airborne microbes

For studying highly lethal microbes

Example microbes

Non-pathogenic Escherichia coli, Saccharomyces cerevisiae

Staphylococcus aureus; Hepatitis viruses

Mycobacterium tuberculosis; SARS-CoV-2

Ebola virus; Lassa virus

Containment measures

Basic safety measures, but open benches and no special equipment required

Controlled access; PPE worn and biosafety cabinets used for containment

Double-door isolation; biosafety cabinets & air filtration required; PPE and respirators worn; decontamination measures taken

Housed in entirely separate buildings, with air filtration; biosafety cabinets required; staff wear full body, positive pressure suits; decontamination measures taken