First published on 
07/31/2017 - 14:30

The Biohazard Warning Sign restricts laboratory access during work with biohazards, communicates the agents in use, and specifies entry or exit requirements. It is the responsibility of the Principal Investigator or supervisor to properly identify and restrict access to the laboratory and to notify emergency and support personnel of any hazards in the laboratory.

The Biohazard Warning sign is posted in addition to the biohazard symbol on the permanently affixed caution sign next to laboratory entry doors. The Biohazard Warning Sign must be permanently affixed to entry doors of the following laboratories/rooms:

  • BSL-2 with BSL-3 practices*
  • BSL-3
  • ABSL-2
  • ABSL-2 with ABSL-3 practices*
  • ABSL-3

*BSL-2 with BSL-3 practices laboratories with approved decontamination procedures to lower containment to BSL-2 must follow the posting requirements in their laboratory-specific standard operating procedures (SOPs).

For BSL-2 laboratories, when work is complete, agents are secured, and surfaces are decontaminated, the Biohazard Warning Sign may be removed or turned over. Affix the Biohazard Warning Sign to entry doors in such a way that it can be easily removed or turned around (e.g., place sign in plastic cover). If the Biohazard Warning Sign is affixed to a BSL-2 laboratory door, support staff such as UW Facilities or Custodial Services will not enter.

For BSL-1/ABSL-1 laboratories, no Biohazard Warning sign is required. The biohazard symbol on the permanently affixed Caution Sign for hazards is sufficient.

How to Complete the Biohazard Warning Sign:

  1. Download the Biohazard Warning Sign.

  2. Enter the room number and date on which the sign will be posted.

  3. BSL-2 is the default biosafety level. Use the dropdown arrow to select the appropriate biosafety level. For BSL-1, a Biohazard Warning Sign is not required unless specified by EH&S/IBC; the biohazard symbol on the permanently affixed UW Laboratory Entry Caution Sign next to laboratory entry doors is sufficient.

  4. Enter biological agent(s).

  5. Use the "Special Procedures, PPE or Precautions for Entry/Exit" section to list specific entry/exit requirements, PPE required for work and any occupational health requirements.

  6. Enter contact information for all Principal Investigators (PI) using the laboratory. Enter an emergency contact including an after-hours phone number.

  7. When finished, print in color on 8 1/2" x 11" white paper. This biohazard symbol on the sign is required to have the orange background with the symbol and lettering in a contrasting color.

  8. Post Biohazard Warning Sign as described above.


Biohazard Warning Sign
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image of the biohazard warning sign


Biological Safety Contact

(206) 221-7770