• Contact/Forms
• Location
• Training/Videos
• Guidelines
• Topics A-Z
• Newsletters
• Home

---

Search: OSEH WWW

Helpful Hints on the Use of Biological Safety Cabinets

A laminar flow biological safety cabinet is a valuable supplement to good sterile technique, but is not a replacement for it. If the cabinet is not operated correctly, it will not provide adequate protection.

Start-up Procedure

1. Many manufacturers recommend the cabinet be left running at all times with the sash at the manufacturer designated operating height. This is usually 8 or 10 inches. Check your owner's manual for the correct window height, as the proper operating position is not variable on these units. If the sash is positioned too high, the user is more likely to contaminate themselves and their work. If the sash is positioned too low, the unit is starved for airflow creating the likelihood of product contamination. Never completely close the window sash with the motor running. This may cause the motor to burn out and will force room air to contaminate the work area. If the cabinet has been turned off, turn the blower switch to ON and do not use the cabinet for at least five minutes to allow time for room air to be removed from the cabinet. Make sure you have airflow, either by listening for blower sound or by feeling the airflow with your fingers. If your cabinet has a gauge make sure it reads other than zero.
2. If your cabinet is equipped with a U.V. light, turn it off and turn on the fluorescent light before beginning work. It is important to avoid hazardous exposure of skin and eyes to U.V. light.
3. Make sure the drain valve is closed and wipe down all the interior surfaces of the BSC with an appropriate disinfectant. Place all the equipment and supplies you will need inside the cabinet to minimize entering and exiting. This includes placing a receptacle for waste and used pipettes inside the BSC. Segregate items that will remain clean from the ones that will get contaminated. Allow the HEPA filtered air to wash over them for a minute or two. Wipe all the supplies with an appropriate disinfectant.

Working in the Cabinet

1. These units are designed for a single operator. Never work two or more people at a time. This will cause enough air disturbance to breach the containment capabilities of the BSC, even in the six-foot cabinets.
2. Never operate a cabinet while a warning light or alarm is on.
3. The operator should be seated with armpits level with the bottom of the sash.
4. Make sure everything necessary for the procedure is already inside and sterile. Slowly introduce gloved hands into the BSC and let air wash over them for a few seconds before beginning. Perform all work using a limited number of slow movements, as quick movements disrupt the air barrier.
5. Keep all materials at least four inches inside the sash opening. Never place items on the front or rear perforated grills. This creates air turbulence that increases the risk of contamination to the user or the research.
6. Activities that create eddy currents (opening and closing doors and windows, personnel walking near the cabinet), should be minimized as these types of activities can disrupt the air barrier.
7. Avoid movements in and out of the cabinet during the procedure.
8. Do not use an open flame in a BSC as it creates turbulence that affects the unit's ability to contain.

Completing Work in the Cabinet

1. All equipment that has come in contact with the research agent should be decontaminated. The cabinet should be allowed to run for at least three minutes with no activity so that the airborne contaminants will be purged from the work area. Then remove the equipment.
2. After all items have been removed, wipe the interior surfaces with a disinfectant.

Common Errors to Avoid

1. Keep papers, paper towels, Kim Wipes, work surface diapers, vials, or any other objects from being pulled in the back, front, or side slots or grills. These items can damage your cabinet's internal components.
2. Do not store equipment or supplies in the cabinet.
3. Do not use the top of the cabinet for storage. The HEPA filter could be damaged and the airflow disrupted.
4. Never disengage the alarm. It indicates improper airflow and reduced performance that may endanger the researcher or the experiment.

Air Flow Patterns in Biological Safety Cabinets

Class I BSC
Class II, Type A BSC
Class II, Type B1 BSC
Class II, Type B2 BSC
Class II, Type B3 BSC (Bench Top Model)
Horizontal Flow "Clean Bench"
Vertical Flow "Clean Bench"

If you have a general question or comment about the department, or are unsure who in OSEH to contact, click here and your question will be directed appropriately.