Introduction to Biohazards: Risk

Management

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Biological agents with the potential to produce harmful effects in humans

Biohazards

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H1N1 flu virus

Pathogenicity• The relative ability of an organism

to cause disease in humans or other organisms

• A pathogenic agent must also be infectious– Those organisms that invade and cause

a SPECIFIC host disease are called etiological agents

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Carriers• An agent infects a host but

does not cause disease in that host

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Routes of infection• Inhalation• Skin/eye contact• Ingestion• Injection

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Mold spores

Special considerations when working with

biohazards

• Pathogenic• Associated

risks• Laboratory-

acquired infections

• Treatments• Allergies

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Hepatitis C virus

Biohazard considerations (con.)

• Infectiousness• Limiting exposure• Special safety

precautions• Is the level of risk of

working with this agent acceptable to the worker?

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Polio virus

Laboratory-Acquired Infections (LAI)

• Infections that can be traced directly to lab organisms handled by or used in the vicinity of the infected individuals– Thousands documented – Hundreds of deaths

Biosafety Guidelines

• Centers for Disease Control and Prevention (CDC)

• National Institutes of Health (NIH)

• Others

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Standard Microbiological Practices

Practices to be used when working with ALL microbiological organisms

• Protect worker• Protect culture

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Standard Rules for Working with Microbes

• Only trained individuals may enter lab• Always wear lab coats and safety glasses• Wash hands after working with organisms and before

leaving lab• No eating, drinking, smoking• Avoid hand to mouth or eye contact• No mouth pipetting• Minimize aerosol production• Work on clean hard benchtop and ALWAYS keep

disinfectant handy• Decontaminate workspace and waste before disposing

Types of Containment

Control of biohazards by isolation and separation of organism from worker

• Primary containment – Personal containment– Physical containment

• Seconary containment– Personal containment– Physical containment

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Biosafety Levels: BSL-1

Well characterized strains not causing disease in healthy humans

• Standard Microbiological Practices

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Biosafety Levels: BSL-2

Agents may cause disease• Usually treatable or preventable• Need autoclave, special

disposal requirements• If aerosols produced, need

biological safety cabinet (Class 1 or II)

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Biosafety Levels: BSL-3

Severe or lethal human disease

• Blood testing for workers

• Entry to lab controlled

• Physical containment for all manipulations. Extra protective gear (respirators)

• No air recirculation, negative airflow

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Biosafety Levels: BSL-4

High risk of lethality, airborne or unknown agent

• Clothing change, and shower upon exit

• All work done in Class III BSC or Class I or II with full body, air –supplied suit

• Must be done in separate building or zone with own contained air system http://www.cdc.gov/media/subtopic/library/LabsScientists/

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Biological Safety Cabinets

Provides containment for aerosols and separates work area from operator and lab while providing clean air

• Able to filter most particles (including most viruses) from air

• Does not remove chemical vapors

Classes of BSC’s

• Class I and Class II cabinets draw air from room and work something like fume hoods

• Class III are glove boxes

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