Biological Laboratory Practices

Biological Safety Cabinets are primary containment devices that protect the personnel, immediate laboratory, research and teaching environment from exposure to biohazard agents, animals, or materials. Other devices, such as the Laminar Flow "Clean Benches", provide product protection only and must not be used when working with any form of biohazard. Environmental Health & Safety (573) 882-7018 must be contacted prior to use of any new or relocated Biological Safety Cabinet or Laminar Flow "Clean Benches".

Biological Safety Cabinets have been divided into three primary classes (Class I, II, and III) based on primary containment capability, design, and cleanliness. Class I and II cabinets are partial containment devices with an air barrier between operator and biohazard work area. Class III cabinets are "absolute" containment devices with a physical barrier between operator and biohazard work area. Refer to the "CDC/NIH Biosafety in Microbiological and Biomedical Laboratories" publication for specific Biological Safety Cabinet information: Biological Safety Cabinets must have annual inspection and certification if used as primary containment.

Laminar Flow "Clean Benches" is a not primary or secondary containment device. They provide the horizontal or vertical positive pressure flow air environment for product protection only. The horizontal flow clean benches are used in clinical, pharmaceutical, and laboratory facilities without toxic, infectious, radioactive, or sensitizing materials. The vertical flow clean benches are useful for certain manipulations of clean materials (e.g. pouring agar plates, etc.) but must not be used for biohazard materials. All Laminar Flow "Clean Benches" must have a "Product Protection Only" label on the front of the bench. These labels are available by contacting Environmental Health & Safety at (573) 882-7018.


Safety Procedures for Biological Safety Cabinets

  1. The cabinet must be on at least 5 minutes before starting biohazard work.
  2. Operate the cabinet hood sash at the manufacturer's design criteria.
  3. Never work with the cabinet UV light source illuminated.
  4. The researcher should wear a closed-front lab coat (or surgical gown) and gloves.
  5. The gloves should overlap the lab coat or surgical gown cuffs.
  6. Perform planning, start-up, wipe down, loading, work practice, purging, unloading, final wipe down and shutdown conscientiously in accordance with good microbiological techniques.
  7. All handling materials needed should be placed in the cabinet before initiating biohazard work to minimize in-and-out motions.
  8. Do not overload the containment area or block front, side, or rear air grills which will reduce or restrict air flow and compromise product or personal protection.
  9. All biohazard work should be at least four inches in front of the cabinet's front grill.
  10. When in use, the lab entry door must be kept closed and traffic minimized.
  11. Do not use electric fans in the room when the biological safety cabinet is operating ­ this will seriously effect the unit's airflow.
  12. Develop procedures for the collection and decontamination of waste materials to avoid clutter and minimize in-and-out motions
  13. Decontaminate the cabinet with an appropriate disinfectant at the end of each operation.
  14. Periodic use of 1-10% household bleach in water is acceptable, but chlorine is corrosive (70% ethanol or quaternary ammonium compounds may also be used if effective against agent).
  15. All biological safety cabinets must be certified for use when first installed, any time the unit is moved or repaired, and on an annual basis.For further information on the use, inspection, compatibility, containment level or selection of biological safety cabinets please contact the Biological Safety Professional at (573) 882-7018.