Understanding personal protective equipment

Biosafety Levels and PPE

Determining the level of personal protective equipment (PPE) required can be tricky. But when dealing with biohazards and other hazardous materials, you don’t want to take a chance. So how do you know what you need? Check BMBL.

Biosafety in Microbiological and Biomedical Laboratories (BMBL) is a resource put out by the U.S. Centers for Disease Control (CDC) that recommends best practices for safely conducting work in clinical and biomedical laboratories. It outlines the level of PPE required based on the work being done in the lab. The biosafety levels and their requirements are summarized here. 


When working with agents not known to consistently cause diseases in healthy adults, Biosafety Level-1 (BSL-1) applies. No extra PPE is required over the standard microbiological practices when handling BSL-1 agents.

BSL-1 personal protective equipment

  • Standard laboratory coats or gowns
  • Gloves
  • Eye and face protection as needed

Other required protective equipment

  • Laboratory bench and sink required for secondary barriers
  • Lab technicians must wash their hands prior to leaving the lab


When working with moderate risk agents associated with varying severities of human disease, Biosafety Level-2 (BSL-2) is required. This includes agents that can be transmitted through percutaneous injury (puncture of the skin), ingestion, or mucous membrane exposure. BSL-2 practices include all BSL-1 practices plus limited access, biohazard warning signs, “sharps” precaution and a biosafety manual defining necessary waste decontamination or medical surveillance policies.

BSL-2 personal protective equipment

  • Gowns
  • Gloves
  • Face and eye protection as needed

Other required protective equipment

  • Biosafety cabinets or other physical containment devices are required for all manipulations of agents that cause splashes or aerosolization of infectious materials
  • Secondary containment barriers for BSL-2 include sinks for handwashing and autoclaves in addition to those required for BSL-1.


Any facility working with indigenous or exotic agents that may cause serious disease or are potentially lethal through inhalation should follow guidelines for BSL-3 facilities. BSL-3 practices include BSL-2 practices as well as controlled access and decontamination of laboratory clothing before washing and all waste. Biosafety cabinets or other physical containment devices are needed for all open manipulation of agents and serve as a primary engineering control barrier.

BSL-3 personal protective equipment

  • Protective laboratory clothing such as coats, gowns, smocks or uniforms designated for lab use
  • Gloves, eye, face and respiratory protection as needed

Other required protective equipment

  • Physical separation from access corridors
  • Self-closing double-door access through an airlock or anteroom
  • Non-recirculation of laboratory air
  • Negative pressure lab spaces
  • A sink near the lab exit


The most hazardous of materials require Biosafety Level-4 (BSL-4). This is required when working with dangerous/exotic agents which pose a high individual risk of lab infections that are frequently fatal, do not have vaccines or treatments and are transmitted via aerosol. It is also required for agents with an unknown risk of transmission and those with a close or identical antigenic relationship to an agent known to require BSL-4.

BSL-4 personal protective equipment

All BSL-3 practices plus the following:

  • Change clothes before entering lab
  • Shower upon exiting lab, and
  • Decontaminate all material prior to exiting facility

Primary barrier required

  • Class I or II biosafety cabinet combined with full-body air-supplied positive-pressure suit


  • Class III biosafety cabinet

IMPORTANT: All procedures must be conducted in one of the types of enclosures described above for BSL-4.

Other required protective equipment

  • Secondary barriers, including everything for BSL-3
  • Separate building or isolated area with dedicated systems for supply and exhaust air
  • Vacuum and decontamination systems

If you have questions about what level of protection your lab requires for a specific application, please contact one of Labconco’s application specialists for assistance. 

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