Basic Documentation
Table Of Contents
- Introduction
- Applicable Definitions (Alphabetical Listing)
- Laboratory Safety
- Hazard Assessment
- Chemical Hygiene Plan
- Chemical Hygiene Responsibilities
- Fume Hoods
- When Required & Safe Usage
- Gloveboxes:
- Face Velocity
- Face Velocity Setback
- Size & ADA Compliance
- CAV (Constant Air Volume) Bypass
- CAV (Constant Air Volume) Conventional
- VAV (Variable Air Volume)
- VAV Diversity
- Automatic Sash Closure
- Safe Operation of Sashes
- Accessories, Services and Explosion Protection
- Ductless
- Auxiliary Air
- (Special Purpose) Perchloric Acid
- Room Air Cross Currents
- Minimum Exhaust
- Monitoring
- Selection Criteria and Performance Specifications
- Laboratory Design & Fume Hood Implementation
- Maintenance
- Periodic Testing
- Test Procedures
- Signage and Recordkeeping
- Shutdown Procedures
- Evaluating CAV (Constant Air Volume) Systems
- Evaluating VAV (Variable Air Volume) Systems
- Biological Laboratories
- Biosafety Level 1
- Biosafety Level 2
- Biosafety Level 3
- Biosafety Level 4
- Ventilation for Biosafety Level 1
- Ventilation for Biosafety Level 2
- Ventilation for Biosafety Level 3
- Ventilation for Biosafety Level 4, Cabinet Laboratory
- Ventilation for Biosafety Level 4, Suit Laboratory
- Containment Levels - Canada
- Containment Levels and Ventilation Requirements: Canada
- Biological Safety Cabinets and Classifications
- Biosafety Cabinet Applications
- Biosafety Cabinets – Installation and Safe Usage Recommendations
- Biosafety Cabinets – Certification and Safe Usage - Canada
- Biological Safety Cabinet Design, Construction and Performance Requirements
- Biosafety Cabinet Testing
- Ventilation Systems
- Local Ventilation -When Required
- Ventilation Rates for Animal Rooms
- Ventilation Rates for Animal Rooms
- Ventilation Rates for Biological Labs
- Ventilation Rates for Chemical Laboratories
- Ventilation rates for Storage areas
- Room Supply Air
- Supply Air Quality and Filtration
- Room and Duct Pressurization
- Human Occupancy, Room Temperature and Humidity
- Animal Rooms Room Temperature and Humidity
- Load Calculations
- Room Sound Level and Vibration
- Emergency Control Provisions
- Energy Conservation
- Monitoring
- Maintenance
- Periodic Inspection and Testing
- Periodic Inspection and Testing - Canada
- Test Records
- Management
- Exhaust Systems
- Configuration
- Leakage
- Components
- Manifolded Systems
- Air Velocity
- Stack Height and Discharge Location
- Operational Reliability
- Recirculated Air and Cross Contamination
- Materials and Fire Protection
- Commissioning
- Commissioning - Canada
- Referenced Publications
Biological Laboratories
Siemens Industry, Inc. 75
Topic Requirement(s) Commentary
Biological
Safety
Cabinets and
Classifications
U.S. Dept. of Health and Human Services, Centers for Disease Control and
Prevention publication: Biosafety in Microbiology and Biomedical Laboratories,
(BMBL) 5th edition 2009:
CLASS I
The Class I BSC provides personnel and environmental protection, but no product
protection. It is similar in terms of air movement to a chemical fume hood, but has a
HEPA filter in the exhaust system to protect the environment. In the Class I BSC,
unfiltered room air is drawn in through the work opening and across the work
surface. Personnel protection is provided by this inward airflow as long as a
minimum velocity of 75 linear feet per minute (lfm) is maintained
6 through the front
opening. Because product protection is provided by the Class II BSCs, general
usage of the Class I BSC has declined. However, in many cases, Class I BSCs are
used specifically to enclose equipment (e.g., centrifuges, harvesting equipment or
small fermenters), or procedures with potential to generate aerosols (e.g., cage
dumping, culture aeration or tissue homogenation).
The classical Class I BSC is hard-ducted (i.e., direct connection) to the building
exhaust system and the building exhaust fan provides the negative pressure
necessary to draw room air into the cabinet. Cabinet air is drawn through a HEPA
filter as it enters the cabinet exhaust plenum. A second HEPA filter may be installed
at the terminal end of the building exhaust system prior to the exhaust fan.
Some Class I BSCs are equipped with an integral exhaust fan. The cabinet
exhaust fan must be interlocked with the building exhaust fan. In the event that the
building exhaust fan fails, the cabinet exhaust fan must turn off so that the building
exhaust ducts are not pressurized. If the ducts are pressurized and the HEPA filter
has developed a leak, contaminated air could be discharged into other parts of the
building or the environment. The use of two filters in the cabinet increases the static
pressure on the fan.
A panel with openings to allow access for the hands and arms to the work surface
can be added to the Class I cabinet. The restricted opening results in increased
inward air velocity, increasing worker protection. For added safety, arm-length
gloves can be attached to the panel. Makeup air is then drawn through an auxiliary
air supply opening (which may contain a filter) and/or around a loose-fitting front
panel.
(Continued on Next Page.)
Note that Class I BSCs are currently being
manufactured on a limited basis; many have
been replaced by Class II BSCs.