Biological Safety in Laboratories

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Biological Safety in Laboratories
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Biological Safety in Laboratories

• Laminar Flow Cabinets
• Laminar or uni-directional means straight
  uninterrupted airflow
• Laminar Flow Cabinets are generally used where
  protection is required for the work or product
  only
• Two types are generally available
• Horizontal the main hepa filter is placed
  immediately behind the working area in a vertical
  position, clean air is blown normally at 0.45m/s
  across the work surface towards the operator.
• Vertical the main hepa filter is placed
  immediately above the working area, clean air is
  blown normally at 0.35m/s vertically down over
  the work surface.

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Biological Safety in Laboratories

• Biological Safety Cabinets
• There are three types of biological safety
  cabinets
• Choosing a cabinet should be done to assess the
  hazard levels of material being handled in
  conjunction with-
• A.C.D.P guidelines Advisory Committee on
  Dangerous Pathogens
• Safety Officer

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Biological Safety in Laboratories

• Class 1
• A class 1 microbiological safety cabinet has an
  air flow into the cabinet in order to protect the
  operator only from potential aerosols penetrating
  in an outward direction from the cabinet
• A hepa filter is fitted immediately above the
  working area where particulate is retained as air
  passes through under a negative pressure
• The exhaust air is either returned to the lab in
  a recirculating mode or exhausted to atmosphere

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Biological Safety in Laboratories

• This cabinet would be used typically in
  laboratories where patient specimens are handled
  prior to identification of any disease
• Class 1 cabinets are generally exhausted to
  atmosphere
• Materials in hazard group 2 and 3 categories are
  normally used in class 1 cabinets, subject to
  protection required

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Biological Safety in Laboratories
Class I Biological Safety Cabinets

• Provide operator and environmental protection
  but
  
  
  
  gives no product protection.
• Class I cabinets are
• open-fronted safety
  
  
  
  cabinets
• The air is drawn from
• the room into the
  
  
  
  work opening
  and it
• passes the operator and
  
  
  
  the product
  before it
• leaves the cabinet via a
  
  
  
  HEPA filter.
  Normally
• ducted to atmosphere.

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Biological Safety in Laboratories

• Class 2
• A class 2 biological safety cabinet has two
  protection factors
• Primarily operator protection
• Secondary product laminar down flow protection
• This cabinet would be used typically for tissue
  culture, media preparation etc where a sterile
  working area is required for patient transfer

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Biological Safety in Laboratories

• Class II Safety Cabinets
• Give both Operator and Work protection with
  Laminar downflow for work and inward airflow for
  operator.
• Must not be confused with simple
• Laminar flow cabinets.
• BS EN 12469 states they can be
• installed with either
• Single exhaust filter, or
• Direct duct connection to extract system.
• UK ACDP regulations ask for double HEPA
• exhaust filter (AEF) only when working
• with material of Hazard Groups higher than 2.
• (Do not use Group 4!)

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Biological Safety in laboratories- Class 2 cabinet
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Biological Safety in Laboratories

• Class 3
• A class 3 biological safety cabinet unlike the
  class 1 and 2 is a fully sealed shell for
  operator protection
• Full barrier protection is maintained
• Manipulation of product is done by using gloved
  sleeved ports
• Air is drawn into the cabinet via a hepa filter
  and exits via a further hepa

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Biological Safety in Laboratories

• Class 3 cabinets are generally used for the
  highest hazard category of product and protection
  under the ACDP guidelines.
• A further class 3 cabinet derivative is the class
  3 1
• A removable night door allows the class 1 mode to
  be used
• Class 3 cabinets are generally ducted to
  atmosphere

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Biological Safety in Laboratories

• Class III Cabinets

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Biological Safety in Laboratories

• Installation of biological safety cabinets
• Siting and testing of safety cabinets is very
  important
• BSEN 124692000 replaced BS5726
• BS57262005 has been re-issued to accommodate
  siting
• Class 1 and 2 cabinets must be KI tested as part
  of commissioning protocol

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Biological Safety in Laboratories
Recommendation for Cabinet Positioning

• Separation of an undisturbed zone around a Safety
  Cabinet from traffic routes
• Spacing when the same operator uses a Safety
  Cabinet and the bench top opposite, or where only
  occasional traffic is anticipated
• Spacing determined by airflow requirements with
  an opposing wall
• Spacing determined by airflow requirements when
  Safety Cabinets are opposite each other

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Biological Safety in Laboratories
Recommendation for Cabinet Positioning

• Pacing determined by airflow requirements with
  adjacent side walls
• Spacing that avoid undue disturbance to airflow.
  Face of column not in front of plane of cabinet
  aperture
• Spacing to avoid undue disturbance to airflow
  when face of column is in front of plane of
  cabinet aperture
• Spacing that avoid undue
• disturbances to airflow
• in relation to door openings

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Biological Safety in Laboratories

• Fume Cupboards
• Fume Cupboards are designed to protect the
  operator
• Usually from a gaseous chemical or solvent hazard
• Biological protection !!!!!

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Biological Safety in Laboratories

• Ducted Fume Cupboards
• Filtration Fume Cupboards

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Biological Safety in Laboratories

• Installation of Fume Cupboards
• Siting and testing is very important
• BS7258 consists of 4 separate parts from usage
  to installation and siting

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Biological Safety in Laboratories

• Summary of both biological safety cabinets and
  Fume Cupboards
• Before choosing a cabinet
• Assess the level of RISK
• Decide the conditions you require
• Chemical or Biological hazard
• Product protection factor

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Biological Safety in Laboratories

• Glossary of terms in general use
• Pre filter
• Hepa filter
• D.O.P Test
• K.I Discus Test
• ACDP

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Biological Safety in Laboratories

• Definitions of hazard groups
• Group 1
• Group 2
• Group 3
• Group 4

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Biological Safety in Laboratories

• Principles of Biosafety - Lab. Practices and
  Techniques
• These will vary according to the level of hazard
  category being studied, but as a routine the
  following practices are generally recommended for
  all laboratories
• Lab. Coats to be worn
• Lab. Doors to be closed during work
• No eating, drinking or smoking
• No mouth pipetting
• Minimise aerosol risk
• Wash hands before leaving lab.
• Safe storage of waste material
• Etc.

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Biological Safety in Laboratories

• Routes of Laboratory Infection
• Aerosol inhalation
• Ingestion
• Injection by syringe
• Absorption through skin
• Absorption through cuts/ abrasions

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Biological Safety in Laboratories

• Sources of Laboratory Infection
• These can contain hazardous bacteria, viruses,
  fungi or parasites and all lab. Samples should be
  treated as potentially dangerous in routine
  clinical labs.
• Blood samples
• Urine samples
• Sputum samples
• Tissue samples
• Faeces samples
• Pond/ river water samples
• Research labs. Must be aware of their work
  hazards and risk to the staff

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Biological Safety in Laboratories

• Principles of Biosafety - Lab. Facility
• There are basically 4 types of laboratory
  facility
• Basic laboratory (no risk)
• Containment laboratory (medium risk)
• High containment lab. (severe risk)

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Biological Safety in Laboratories

• Containment level 1
• Instruction in lab. procedures
• Easy to clean
• Lab. door closed during work
• Lab. Coats to be worn
• No eating, drinking, smoking
• No mouth pipetting
• Minimise aerosols
• Wash hands before leaving lab.
• Safe storage of waste material
• Report all accidents

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Biological Safety in Laboratories

• Containment level 1
• Hazard group 1 - P1
• Doors closed during work
• normal lab. procedures

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Biological Safety in Laboratories

• Containment level 2
• Key issues - as per level 1 plus the following
• Training in handling pathogens
• Work supervision
• Adequate space for worker (24M3)
• Elbow taps
• Autoclave in same building
• Special lab. coats
• Biohazard cabinets should be used
• Disinfecting after use

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Biological Safety in Laboratories

• Containment level 2
• Hazard group 1 - 2 / P1 -P2
• Use Class II safety cabinet
• Use autoclave
• Protect against aerosol generation

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Biological Safety in Laboratories

• Containment level 3
• Key issues - as per level 2 plus the following
• Full training
• High work supervision
• Restricted access to lab.
• Biohazard labels
• Negative pressure room
• Laboratory autoclave
• Gloves must be worn
• Biohazard cabinets must be used
• Lab. specific equipment

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Biological Safety in Laboratories

• Containment level 3
• Hazard group P1 -P3
• Keep rooms at negative pressure so air flows from
  outdoors to indoors
• Use Class II safety cabinet

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Biological Safety in Laboratories

• Containment level 4
• Key issues - as per level 3 plus the following
• Code of practice/ safety officer
• Specific training/ full supervision
• Lab. must be sealable
• Separate building
• Negative pressure via double HEPA
• Entry via airlock
• Interlocked air inlet/ exhaust
• Complete clothing change
• Double ended autoclave
• All waste to be made save

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Biological Safety in Laboratories

• Containment level 4
• Hazard group 4, P1 -P4
• Keep rooms at negative pressure
• Use Class III safety cabinet
• Install airlock and shower

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Biological Safety in Laboratories
Filter Technology and Airflow Principle
Pre-filter Fan Plenum HEPA
Work Area
Filter
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Biological Safety in Laboratories
Filter Technology and Airflow Principle

• What is a HEPA Filter?
• HEPA stands for High Efficiency Particulate Air
  filter.
• They are normally 99.997 efficient against a
  particle size of 0.3µm. (Eurovent EN 130911999,
  EN1822-1 Class H14 or higher.)
• What is an ULPA filter?
• ULPA stands for Ultra Low Penetration Air filter.
• They are normally 99.999 efficient against a
  particle size of 0.3µm. (Eurovent Class U 14 or
  higher.)

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Biolological Safety in Laboratories
Filter Technology and Airflow Principle Filter
construction
Air flow
Filter Medium
Gasket
Filter Frame
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Biological Safety in Laboratories
Filter Technology and Airflow Principle
Laminar Air Flow (Unidirectional)
Filter Media
Laminar Sheet
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Biological Safety in Laboratories
Filter Technology and Airflow Principle
Diagram of Particle Filtration 1. Small
Particle Impaction 2. Electrostatic Attraction 3.
Brownian Motion (very small particles) 4.
Large Particle Impaction
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Biological Safety in Laboratories

• Decontamination
• Full decontamination is only necessary
  infrequently
• It is normally carried out by using formaldehyde
  vapour to ensure the filters and the whole
  cabinet is sterilised
• It must be carried out prior to any servicing on
  the cabinet or filters
• Formaldehyde is due to be replaced in early 2009
  under new COSHH directive and will be replaced
  with Vaporous Hydrogen Peroxide (VHP)