Introduction to Biosafety Levels BSLs 14

1
Introduction to Biosafety Levels(BSLs) 1-4

• Robert Heckert, DVM, PhD, CBSP
• BioSafety Consultant
• Robert Heckert Consulting

2
Principles of Biosafety

• Fundamental objective
• Contain potentially harmful biological agents
• Purpose of containment
• Reduce or eliminate exposure of lab workers,
  other persons, and outside environment
• Vaccines
• May provide increased level of personal protection

3
Lab Practices Techniques

• Strict adherence to standard microbiological
  practices and techniques
• Workers must be
• Aware of potential hazards
• Trained
• Proficient in safe practices techniques
• Responsible scientist provides appropriate
  training

4
Biosafety Manual

• Developed specifically for each laboratory
• Identifies hazards
• Specifies practices procedures to minimize or
  eliminate these hazards
• Required reading
• Responsible scientist is
• Trained knowledgeable in techniques, safety
  procedures, and associated hazards

5
In addition

• Responsible scientist may choose additional
  safety practices.
• Lab personnel, safety practices and techniques
  must be supplemented by
• Appropriate facility design
• Engineering features
• Safety equipment
• Management practices

6
Safety Equipment

• Includes BSCs, enclosed containers, engineering
  controls to minimize exposure to hazardous
  biological materials
• BSC - principle device to contain infectious
  splashes, splatters or aerosols
• Primary barrier to
• Protect lab personnel
• Protect environment
• Prevent contamination of materials

7
Safety Equipment

• For personal protection
• Gloves
• Coats, gowns, sleeve covers
• Boots, shoe covers
• Respirators
• Face shields, goggles, safety glasses
• Used with BSCs or as primary barrier
• e.g., animal studies, production activities

8
Secondary Barriers

• Facility design and construction
• Lab worker protection
• Barrier to protect persons outside lab
• Protects community from infectious agents
• Recommended barriers
• Depend on transmission of specific agents
• Contact versus inhalation exposure

9
Biosafety Levels

• Combinations of lab practices and techniques,
  safety equipment, and laboratory facilities
• Appropriate level determined by risk assessment.
• Specifically appropriate for
• Operations performed
• Known or suspected routes of infection
• Lab function or activity

10
Interrelationship of Biosafety and Containment
Facility Design
Standard and Special MicrobiologicalPractices
Safety Equipment
11
Risk Groups

• Described in NIH Guidelines and WHO Laboratory
  Safety Manual
• Classification of agents based only on
  association with and resulting severity of
  infection for humans
• BSLs additionally consider
• Mode of transmission
• Procedural protocols
• Staff experience and other factors

12
Determining BSLs

• Conditions under which the agent ordinarily can
  be handled in the laboratory
• Based on risk assessment
• Established by responsible scientist
• Resources include
• Published data
• Biological safety officer (BSO)
• Institutional Biosafety Committee (IBC)

13
Risk Assessment

• Consideration for
• Manipulations to be done
• Volumes handled
• Virulence
• Pathogenicity
• Antibiotic resistance patterns
• Vaccine and treatment availability
• Other factors

14
BSL-1

• Practices, safety equipment, facility design
  appropriate for
• Student educational training and teaching labs
• Labs working with defined and characterized
  agents not known to cause disease in normal
  health adult humans
• Examples
• Bascilas subtilis, Naegleria gruberi
• Exempt organisms under NIH Guidelines

15
BSL-1

• A basic level of containment
• Relies on
• Standard microbiological practices
• No special primary or secondary barriers
• Hand washing

16
BSL-2

• Practices, equipment, and facility design and
  construction applicable to
• Clinical, diagnostic, teaching labs, and
• Other labs working with indigenous moderate-risk
  agents present in community and associated with
  human disease of varying severity

17
BSL-2

• Can work on open bench with good microbiological
  techniques, providing probability for splashes
  and aerosols is low.

18
BSL-2

• Examples
• Hepatitis B virus, HIV, the salmonellae,
  Toxoplasma spp.
• Any human-derived blood, body fluid, tissue or
  primary human cell lines where presence of an
  infectious agent is unknown

19
BSL-2

• Primary hazards
• Percutaneous or mucous membrane exposure
• Ingestion of infectious materials
• Take extreme precautions with contaminated
  needles or other sharps.
• Use of BSCs and other primary containment devices
  recommended when potential for splashes and
  aerosols is high

20
BSL-3

• Practices, equipment, facility design and
  construction applicable to
• Clinical, teaching, research, or production
  facilities
• Work with indigenous or exotic agents with
  potential for respiratory transmission, and
• May cause serious and potentially lethal
  infection
• Examples M. tuberculosis, C. burnetii

21
BSL-3

• Primary hazards
• Exposure to infectious aerosols
• Autoinoculation
• Ingestion
• Emphasis on primary secondary barriers to
  protect
• personnel in contiguous areas
• the community
• the environment

22
BSL-3

• Primary barriers
• All agent manipulations in BSC or other enclosed
  equipment
• Secondary barriers
• Controlled access to laboratory
• Ventilation requirements to minimize release of
  infectious aerosols from lab

23
BSL 3 Ag

• No Primary Containment (loose housed)
• Large Infected Species (any)
• Environmental Protection
• Potential Internal Transmission (room to room)
• What and how the agent will be used!!!

24
Laboratory Work with Ag Agents

• All Agriculture pathogens can be worked with at
  BSL2, BSL3 or BSL3 with enhancements
• Reasons
• the agent is not highly contagious,
• a vector is needed for transmission,
• there are various containment practices put in
  place

25
BSL 3 Ag

• APPLIES TO LOOSE HOUSED ANIMALS INFECTED WITH
  SOME AGENTS
• Decontamination/sterilization of liquid effluent
• HEPA Filter treatment of exhaust and/or supply
  air
• Provision for personnel Shower Out capability
• Some restriction on contact with domestic animals
• PRESURE DECAY TESTING OF WALLS IN ANIMAL ROOMS
  ONLY (new construction)

26
BSL-3 Ag Agents

• African swine fever virus
• Avian influenza virus (highly pathogenic)
• Classical swine fever
• Foot and mouth disease virus
• Lumpy skin disease virus
• Contagious bovine pleuropneumonia
• Contagious caprine pleuropneumonia
• Newcastle disease virus
• Peste des petits ruminants
• Rift Valley fever virus
• Rinderpest virus

27
BSL-4

• Practices, safety equipment, facility design and
  construction for
• Work with dangerous and exotic agents
• Posing high individual risk of life-threatening
  disease
• May be transmitted via aerosol route
• There is no available vaccine or therapy
• Example Hemorrhagic fever viruses

28
BSL-4

• Primary exposure hazards
• Infectious aerosols
• Mucous membranes
• Broken skin
• Autoinoculation
• All agent manipulations pose high risk to
• All laboratory personnel
• The community
• The environment

29
BSL-4

• Extreme containment for lab personnel
• Class III BSC or
• Full-body, air supplied positive-pressure
  personnel suit
• Maximum containment of laboratory
• Separate building or completely isolated zone
• Complex, specialized ventilation requirements
• Special waste management systems

30
BSL-4

• Laboratory director
• Responsible for safe operations
• Assesses risks, applies recommendations
• Factors considered
• Special characteristics of agent
• Training and experience of personnel
• Procedures being conducted
• Nature or function of the laboratory