Biological Safety Cabinet vs. Fume Hood — What’s the Difference?
Biological safety cabinets (BSCs) and chemical fume hoods are both essential laboratory safety equipment, but they serve fundamentally different purposes. Using the wrong one can put researchers at risk. This guide explains when to use each, how they work, and how to choose the right containment device for your lab.
Quick Comparison
| Feature | Biological Safety Cabinet | Chemical Fume Hood |
|---|---|---|
| Primary protection | User + product + environment | User only |
| Hazard type | Biological agents (bacteria, viruses, cells) | Chemical vapors, fumes, gases |
| Airflow pattern | HEPA-filtered laminar (vertical or horizontal) | Inward and upward through exhaust duct |
| Exhaust | HEPA-filtered (recirculated or ducted) | Ducted to building exterior |
| Product protection | Yes — HEPA-filtered air over work surface | No — non-sterile room air enters |
| Chemical use | Small quantities only (Type B2 for volatile) | Yes — designed for chemical handling |
| Standards | NSF 49 (US), EN 12469 (EU) | ANSI Z9.5, ASHRAE 110 |
| Certification | Annual NSF 49 field certification required | Annual face velocity testing required |
| Cost (unit) | $5,000–$25,000+ | $3,000–$15,000+ |
When to Use a Biological Safety Cabinet
- Working with infectious agents (BSL-1 through BSL-4)
- Cell culture and tissue culture work
- Sterile compounding and aseptic processing
- Work requiring product protection (contamination-free environment)
- Handling recombinant DNA (NIH Guidelines)
- Diagnostic microbiology
When to Use a Chemical Fume Hood
- Working with volatile organic solvents
- Acid digestion and strong acid/base handling
- Chemical reactions producing toxic vapors
- Weighing or dispensing hazardous powders
- Any work producing chemical fumes, gases, or particulates
View our chemistry hood product page →
BSC Classes Explained
| BSC Class | Personnel | Product | Environment | BSL Level |
|---|---|---|---|---|
| Class I | ✅ Yes | ❌ No | ✅ Yes | BSL-1, 2, 3 |
| Class II (A2, B1, B2) | ✅ Yes | ✅ Yes | ✅ Yes | BSL-1, 2, 3 |
| Class III | ✅ Yes | ✅ Yes | ✅ Yes | BSL-3, 4 |
Common Mistakes
- Using a fume hood for biological work — Fume hoods do NOT have HEPA filters and do NOT provide product protection. They cannot contain biological aerosols safely.
- Using a BSC for chemical work — Standard BSCs (Type A2) recirculate 70% of air through HEPA filters back into the room. Chemical vapors pass through HEPA filters and contaminate the lab. Only Type B2 BSCs (100% exhaust) can handle volatile chemicals.
- Using a laminar flow hood instead of a BSC — Laminar flow hoods provide product protection only. They blow air toward the user and offer ZERO personnel protection.
Frequently Asked Questions
Can I use chemicals in a biological safety cabinet?
Only in very small quantities with low volatility. For volatile chemicals, you need a Class II Type B2 BSC (100% externally exhausted). For significant chemical work, use a chemical fume hood instead.
Do I need both a BSC and a fume hood in my lab?
If your lab works with both biological agents and hazardous chemicals, yes — you need both. A BSC for biological work and a fume hood for chemical work. They are not interchangeable.
How often do BSCs need certification?
BSCs must be field-certified annually per NSF 49, and after any move, repair, or filter change. Certification tests HEPA filter integrity, airflow velocities, and containment performance.
Need help choosing between a BSC and a fume hood? Call (801) 717-8834 or contact our lab design team. We’ll assess your application and recommend the right safety equipment.