1. General Requirements for a BSL-3/4 Laboratory
Mircea Panait, Ovidiu Ciungradi, Adrian Onu, Dorel Lucian Radu

2. Classification of infective microorganisms by risk group
Risk group 1 (no or very low individual and community risk)
A microorganism that is unlikely to cause human or animal disease.
Risk group 2 (moderate individual risk, low community risk)
A pathogen that can cause human or animal disease but is unlikely to be a serious hazard to laboratory workers, the community, livestock or the environment.
Laboratory exposures may cause serious infection, but effective treatment and preventive measures are available and the risk of spread of infection is limited.
Risk group 3 (high individual risk, low community risk)
A pathogen that usually causes serious human or animal disease but does not ordinarily spread from one infected individual to another.
Effective treatment and preventive measures are available.
Risk group 4 (high individual and community risk)
A pathogen that usually causes serious human or animal disease and that can be readily transmitted from one individual to another, directly or indirectly.
Effective treatment and preventive measures are not usually available.

3. National or regional classification of microorganisms by risk group
Pathogenicity of the organism
Mode of transmission and host range of the organism
Existing levels of immunity in the local population
Density and movement of the host population
Presence of appropriate vectors
Standards of environmental hygiene
Local availability of effective preventive measures
Prophylaxis by immunization or administration of antisera
Sanitary measures (food and water hygiene)
Control of animal reservoirs or arthropod vectors
Local availability of effective treatment
Passive immunization
Post exposure vaccination
Use of antimicrobial, antiviral and chemotherapeutic agents

4. Relation of risk groups to biosafety levels, practices and equipment
Laboratory Type
Laboratory Practices
Safety Equipment 1
Basic – Biosafety Level 1
Basic teaching, research
GMT
None; open bench work 2
Basic – Biosafety Level 2
Primary health services; diagnostic, research
GMT plus protective clothing, biohazard sign
Open bench plus BSC for potential aerosols 3
Containment – Biosafety Level 3
Special diagnostic, research
As Level 2 plus special clothing, controlled access, directional air flow
BSC and/or other primary devices for all activities 4
Maximum containment – Biosafety Level 4
Dangerous pathogen units
As Level 3 plus airlock entry, shower exit, special waste disposal
Class III BSC, or positive pressure suits in conjunction with Class II BSCs, double-ended autoclave (through the wall), filtered air

5. Summary of biosafety level requirements (1)2 3 4
Isolation of laboratory No
Desirable
Yes
Room sealable for decontamination
Ventilation:
inward air flow
mechanical via building system
mechanical, independent
HEPA filtered air exhaust
Double-door entry
Airlock
Airlock with shower
Anteroom
Anteroom with shower
Effluent treatment

6. Summary of biosafety level requirements (2)1 2 3 4
Autoclave:
on site
Yes
in laboratory room No
Desirable
double-ended
Biological safety cabinets:
Class I
Optional
Class II
Yes, in conjunction with suit laboratories
Class III
Yes, in conjunction with cabinet laboratories

7. BSL-4 project
BSL-4 project or facility can operate correctly and in safe condition if we have:
A good design, engineering, construction and validation of the installation.
A trained personnel and good procedure system.
A good maintenance team which ensure the well state of the installation.

8. General considerations regarding BSL-4 laboratory – from the outside
BSL-4 design features include the following:
All seams, joints and doors are sealed to make the building airtight. You can not open a window. Air does not flow in or out under the doors.
Air is pumped in and out of the building through a filtration system that catches the tiniest microscopic particles, including bacteria and viruses.
All air ducts are welded stainless steel and tested to be airtight.
Inside many BSL-4 facilities, laboratories are surrounded by buffer corridors that help protect the labs in the event of bombing attack from outside.
Features such airlocks, fumigation chambers, disinfectant “dunk tanks” and waste water treatment systems ensure that absolutely everything that leaves a BSL-4 laboratory is decontaminated.

10. A security checkpoint at the entry to the site
A secured perimeter around the building
A buffer between the building and parking areas, drop-off zones
On-site 24-hour surveillance
An additional vehicle checkpoint for lab employees, visitors
A secured entryway, including security guards, surveillance cameras, an intercom system and card access readers
A delivery vehicle inspection area
The building also contains numerous safety and security measures throughout

11. General considerations regarding BSL-4 laboratory – interior security
Once pass outside security, BSL-4 lab workers must pass an interior security station
Security measures will include combinations of the following:
Extensive background checks prior to employment for everyone who works in the building
Guards who check everyone’s identification and credentials
Special identification cards that are scanned to provide an electronic record of who goes in and out, and when
Identifications devices such as retinal or fingerprint scanners

12. Scouring the air – HEPA filter and filtration inspection verification

13. Changing room

14. Inside the lab Entries and exits have double-door airlocks
Work surfaces are regularly decontaminated
Researchers are vaccinated against the pathogen they are studying
All solid and liquid waste is decontaminated by heat sterilization, gaseous sterilization or liquid disinfectant

15. Biocontainment Suits and Biosafety Cabinets
The airtight, pressurized suits have dedicated life support systems that include air compressors, alarms and emergency backup air tanks and a HEPA air filtration system
Work stations called biosafety cabinets serve as additional barriers
Different type of biosafety cabinet can be used (Class II or III)

16. Decontaminating Shower

17. Community and Environment