Biological Safety Cabinets
The Biological Safety Cabinet (BSC) protects the researcher, the research materials and other lab members through a simple system of airflow and filters. A BSC needs to be used whenever activities anticipated to generate droplets, splashes and aerosols with potentially infectious biological materials.
BSCs versus Other Laboratory Equipment
Clean benches (a.k.a., laminar flow hoods) are not BSCs and do not provide worker or environmental protection- these should not ever be used with biohazardous materials. Chemical fume hoods and BSCs are not interchangeable because a BSC contains HEPA filters that do not filter out chemical vapors and fume hoods cannot control contamination of your experiments.
Your BSC must be certified every 12 months (request certification via eShop). This is a performance test to ensure the filters and motors are functioning properly. There will be a sticker on your BSC that tells you the date your BSC was last tested – make sure that date is within the past year, and that the Magnehelic gauge reading matches the value on the sticker. Don’t use the cabinet of the gauge reading doesn’t match the sticker value.
Personal Protective Equipment (PPE)
Protect yourself from and prevent contamination of your work by always wearing a buttoned up lab coat and gloves at minimum. Be consistent. Any time you leave the BSC, remove gloves and decontaminate items to be removed.
Operating in the BSC
Plan ahead and take only what you need into the BSC. Remember to include waste collection supplies (e.g., biohazard bags, sharps disposal containers). Use slow controlled hand/arm motions inside the cabinet, and move your hands in and out of the cabinet in a linear, not radial, fashion. Work toward the middle of the cabinet for ultimate protection, with a workflow of clean-to-dirty materials. The location of the BSC in the room also matters due to potential cross drafts.People walking by can create turbulence, potentially pulling aerosols out of the cabinet into the face of the user and cause dirty air to potentially contaminate your material inside the BSC. Two people working in BSC is only acceptable if the work is compatible.
Decontamination and Cleaning
Decontaminate the BSC before and after every use to prevent cross-contamination. Use a 1:10 fresh bleach solution followed by a 70% ethanol rinse to prevent corrosion and achieve good disinfection, or contact EHS if you need a bleach alternative. You can review Disinfectant Selection for further guidance. Reaching the back and sides of the biosafety cabinet can be difficult. To avoid sticking your head in the BSC or possibly injuring yourself, use a Swiffer mop to clean those areas. Clean and decontaminate the space below the work surface, which can accumulate broken glass, spilled materials, and general gunk. Use tongs to remove broken glass. Establish a regular schedule to perform this activity, perhaps once or twice a year, and as needed.
Things to Avoid
- Don’t rely on UV – UV light only works on surfaces, not what’s underneath. Dust and other materials condense on the bulb, and the germicidal functions burn out long before the blue light does. The bulb should be dusted weekly and should be changed annually. UV can be a supplemental treatment, but a good chemical disinfection is much more reliable.
- Don’t spray corrosive disinfectants – use a squirt or drizzle bottle to apply disinfectants such as bleach, and follow with an ethanol rinse to prevent corrosion and damage to the BSC’s internal parts.
- Don’t block the grills or clutter the BSC - Blocking the front or back perforated grill, and cluttering your work surface negatively affects airflow and containment of aerosols.
- Don’t raise the sash - BSCs are designed to operate at a fixed sash height (this is very different from a chemical fume hood).
- Don’t use volatile or flammable chemicals - BSCs are not designed to filter or contain chemicals, so they will recirculate back into the room. Volatile or flammable chemicals may cause an explosion upon contact with electrical parts by becoming concentrated inside the BSC, and you and your colleagues may be breathing them in when they recirculate into the room.
- Don’t use Bunsen Burners inside the BSC - they create unnecessary fire hazards, explosion hazards (if there is a gas connection) and air turbulence, and there are many safer alternatives, including the Bacticinerator, the Flame Boy, and others (contact EHS).
The following resources are available for a more in-depth look at BSC operation and maintenance:
- Review Section 3.2 of the Biosafety Manual
- The Biosafety Cabinet site provides additional biosafety cabinet guidance
- Attend “Working Safely in Biosafety Cabinets and Other Hoods” class – find it in CULearn under Activity 4115 – CVM-BioCabFH
- Contact the Biosafety team at askEHS for tailored, hands-on BSC training in your lab or at our training lab, or for help finding an alternative to your Bunsen Burner. If you work at the Vet College, you can also request this from Paul Jennett.
- Check out our related GBPs on aerosol-producing equipment, aspirator set up, and other items that might impact the way you use your BSC
- Check out our Cornell EHS YouTube channel that features biosafety cabinet videos