Accidents

B. Laboratory Fumigation

If there has been a spill of infectious materials that is so widespread, to the extent that standard clean up can not contain it or decontaminate it, the BSL-3 facility must be entirely fumigated for decontamination. The following procedure will be performed by the BSL-3 Laboratory Manager or the Wistar Institute Safety Officer. Materials stored in vials at -800C and over liquid nitrogen should be safe from the effects of this fumigation. However, no similar guarantees can be made about the viability of materials stored in incubators or elsewhere within the BSL-3 facility.

Formaldehyde Fumigation Procedure:

Prepare BSL-3:

Remove all lab personnel. Close all incubator and refrigerator doors. Set air conditioning to 28°C (heat room). Turn off biosafety cabinets (timed period, for 13 hours only).

Fumigation:

Make formalin mixture in fume hood (75 ml 37% formaldehyde, 150 ml H2O). Transport mixture into BSL-3 in a suitable carrier. Add mixture to a metal fumigation beaker on hot plate that has been hooked up to a timer set for two hours and that has been placed in view of the window.

Leave BSL-3 immediately after turning on timer to the hotplate. Seal outer door and window filters, put biohazard tape visibly around door, and lock securely.

Incubation:

Allow beaker to boil dry and leave room "as is" overnight. The formaldehyde is removed from the facility by the Class II cabinets, which turn on automatically after 13 hours. Once the room is at negative pressure, unseal tape from around the window filters.

After 24 hours, the formaldehyde should have been evacuated. Unseal the door and return air conditioning to normal setting. Make sure formalin has dispersed before allowing any BSL-3 personnel in.


The Wistar Institute
Biosaftey Level 3 Laboratory Code of Practice