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Use of Open Flames

Current construction codes prohibit the installation of natural gas lines to biological safety cabinets. Manufacturer labels indicate that gas should not be plumbed into biological safety cabinets. This is due, in part, to the risk of gas from leaks becoming concentrated because of air recirculation in the cabinet.

Natural gas is no longer being installed in new or moved biological safety cabinets at the university. Gas lines are not being removed from existing cabinets but its use is discouraged. Per CDC guidelines

"Open flames are not required in the near microbe-free environment of a biological safety cabinet. On an open bench, flaming the neck of a culture vessel will create an upward air current which prevents microorganisms from falling into the tube or flask. An open flame in a BSC, however, creates turbulence which disrupts the pattern of HEPA-filtered air supplied to the work surface. When deemed absolutely necessary, touch-plate microburners equipped with a pilot light to provide a flame on demand may be used. Internal cabinet air disturbance and heat buildup will be minimized. The burner must be turned off when work is completed. Small electric "furnaces" are available for decontaminating bacteriological loops and needles and are preferable to an open flame inside the BSC. Disposable sterile loops can also be used."

In addition to fire and gas leak hazards, the use of an open flame in a biological safety cabinet causes air turbulence altering airflow patterns that may disrupt the protective air barrier. Use of a flame should not be a substitute for good aseptic technique. Shielded electric incinerators or hot bead sterilizers are good alternatives to open flames to sterilize surgical instruments, biological loops, and needles.
Note: Be aware that UV lights can cause gas line tubing to deteriorate and present a gas leak hazard.