Download Biological Hazards Routes of Entry

Biological Hazards
Routes of Entry
Skin Absorption
Inhalation
Injection
Ingestion
Aerosols
 Particles suspended in air
 Bacteria, parasites, viruses,
fungi
 Respirable size invisible
 Produced by variety of lab
activities
 Removable by
HEPA filtration
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
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
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
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
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
Decontamination
 Removing contamination by
killing microbes, rendering
items safe for disposal or use
 Principal methods
Autoclave
Chemical disinfectants
Incineration
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
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
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
Autoclave Parameters




temperature 121oC
pressure
15 gauge
time
30-60 minutes
displacement is dependent
upon proper loading for
adequate steam penetration
Indicators

biological

chemical
Chemical
Disinfectants
Surfaces and equipment
which cannot be autoclaved
After spills of biohazardous
material
In discard jars and pipette
jars
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