Biosafety Level Classification

Biosafety Levels (BSL) define the containment precautions required when handling biological materials. Classification is based on risk assessment, transmission routes, and potential impact on human health.

BSL 1–4

Cytion supplies BSL-1 and BSL-2 cell lines only

Our catalog is restricted to materials suitable for standard research laboratories. The classifications below are provided as a general reference for laboratory planning and risk assessment.

Available from Cytion

BSL-1 cell lines — minimal risk, no known disease association
BSL-2 cell lines — moderate risk, handled in standard biosafety cabinets

Not supplied

BSL-3 agents — high-containment research only
BSL-4 agents — maximum-containment facilities only

Biosafety Levels

Four ascending levels of containment, from basic to maximum security.

BSL-1

Minimal Risk

Agents not known to consistently cause disease in healthy adults.

Required Practices

Standard microbiological practices
Work on open bench tops
No special containment equipment required
Lab coats and gloves as needed

Example Agents

E. coli K-12, Bacillus subtilis, S. cerevisiae

BSL-2

Moderate Risk

Agents associated with human disease presenting moderate hazards.

Required Practices

Limited laboratory access
Biohazard warning signs posted
Biosafety cabinets for aerosol-generating work
Decontamination of infectious waste

Example Agents

Hepatitis B, HIV, Salmonella, MRSA

BSL-3

High Containment

Agents that may cause serious or potentially lethal disease via inhalation.

Required Practices

Controlled access
All work performed in biosafety cabinets
Respiratory protection where required
Separated laboratory environment

Example Agents

M. tuberculosis, SARS-CoV, West Nile Virus

BSL-4

Maximum Containment

Dangerous and exotic agents with high risk of life-threatening infection.

Required Practices

Positive-pressure suit
Dedicated ventilation systems
Full decontamination procedures

Example Agents

Ebola virus, Marburg virus, Nipah virus

Safety Requirements Comparison

How containment requirements escalate from minimal-risk handling to maximum-containment facilities.

Requirement	BSL-1	BSL-2	BSL-3	BSL-4
Open Bench Work	✓	–	✕	✕
Biosafety Cabinet Required	✕	✓	✓	✓
Restricted Access	✕	✓	✓	✓
Decontamination of Waste	✕	✓	✓	✓
Controlled Ventilation	✕	✕	✓	✓
Double-Door Entry	✕	✕	✓	✓
Full Pressure Suit	✕	✕	✕	✓
Chemical Shower Exit	✕	✕	✕	✓

– indicates a partial or conditional requirement.

Additional Resources

Reference materials from international authorities for biosafety classification and laboratory practice.

WHO Laboratory Biosafety Manual

Comprehensive international guidelines for laboratory biosafety practices and risk assessment.

GenTSV Documentation

German Genetic Engineering Safety Regulation — official documentation and classification criteria.

CDC Biosafety Resources

U.S. Centers for Disease Control guidelines on biosafety levels and containment protocols.

Need Biosafety Guidance?

Our team can help you determine the appropriate biosafety level for your research and recommend cell lines that match your facility's containment.