1. Biological Hazards Routes of Entry
Skin Absorption
Inhalation
Injection
Ingestion

2. Aerosols Particles suspended in air
Bacteria, parasites, viruses, fungi
Respirable size invisible
Produced by variety of lab activities
Removable by
HEPA filtration

3. Factors Determining IF Infection Occurs
The viability of the microbes
The concentration of the particles in the aerosol
The size of particles in the aerosol
The persistence of the aerosol

4. Biological Hazards Causes of Infection
Needle puncture
Other “sharps” (broken glass, blades, pipettes, etc.)
Contact with infectious spills, sprays, aerosols
Aspiration through pipette
Animal bites or scratches
Majority not traced to specific incident

5. Biohazards - Risk Groups
Group 1 - low individual and low community risk
Group 2 - moderate individual and low community risk
Group 3 - high individual and low community risk
Group 4 - high individual and high community risk

6. Level 2 Physical Requirements
Away from public, offices, and patient care areas
Biohazard sign at entrance
Impervious surfaces
Coathooks for lab coats near entrance
Autoclave in or near lab
Self-closing lab doors

7. Level 2 Operational Requirements
Class I or II biological safety cabinets
Closed-cup centrifugation
Containment of infected animals
Emergency spill plan
HEPA filtered vacuum lines
Lab coats removed upon exiting
Skin protection (gloves)
Decontamination of glassware
Service personnel clean floors only, lab personnel clean work surfaces

8. Decontamination
Removing contamination by killing microbes, rendering items safe for disposal or use
Principal methods
Autoclave
Chemical disinfectants
Incineration

9. Autoclaves
Efficiency depends on pressure, temperature, moisture contact, time
Maintain and calibrate frequently
Wash regularly with detergent
Open containers to facilitate contact
Verify effectiveness with indicators
Follow safe operation procedures

10. Autoclave Hazards Heat/steam associated injuries glass breakage
chemical reactions if chemicals inadvertently placed inside
explosive decomposition of items (tubes) made of cellulose nitrate
biological hazard of contaminated material

11. Autoclave selection type of autoclave simplicity of use and design
rapid air removal for steam penetration and rapid steam exhaust
prohibition of escape of microbes into environment
ability to be monitored for temperature and pressure

12. Autoclave Parameters temperature 121oC pressure 15 gauge
time minutes
displacement is dependent upon proper loading for adequate steam penetration

13. Indicators
biological
chemical

14. Chemical Disinfectants
Surfaces and equipment which cannot be autoclaved
After spills of biohazardous material
In discard jars and pipette jars

15. Choosing a Disinfectant
Types of organisms suspected or known contaminants
Items/surfaces to be contaminated
Toxicology of disinfectant
Cost of disinfectant
Corrosiveness of disinfectant
Shelf life and required dilution
Material which inactivates disinfectant