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
Fume Hoods
Siemens Industry, Inc. 23
Topic Requirement(s) Commentary
Face
Velocity
(Continued)
In addition to maintaining proper fume hood face velocity, fume hoods that reduce the
exhaust volume as the sash opening is reduced should maintain a minimum exhaust
volume to ensure that contaminants are diluted and exhausted from a hood. The
chemical fume hood exhaust airflow should not be reduced to less than the flow rate
recommended in ANSI/AIHA Z9.5.
A.8.9.1 A person walking past the hood can create sufficient turbulence to disrupt a
face velocity of 0.5 m/sec (100 ft/min). In addition, open windows or air impingement
from an air diffuser can completely negate or dramatically reduce the face velocity
and can also affect negative differential air pressure.
Scientific Equipment & Furniture Association
SEFA 1–2006 Recommended Practices for Laboratory Fume Hoods
4.4.1 Face velocity shall be adequate to provide containment. Face velocity is not a
measure of safety.
The most widely accepted range of average face velocities is 60 FPM to 100 FPM.
The measured deviation across the face may vary + 20 FPM.
American Conference of Governmental Industrial Hygienists (ACGIH)
INDUSTRIAL VENTILATION A Manual of Recommended Practice, 27th Edition
3.7.1 If the enclosure is not complete and an operator must be located at an opening,
such as in front of a laboratory hood, the maximum control velocity should not exceed
125 fpm. Air velocities higher than this value will create eddies in front of the operator
which may pull contaminants from the hood into the operator’s breathing zone.
3.7.2 For low activity radioactive laboratory work, a laboratory fume hood may be
acceptable. For such hoods, an average face velocity of 80 t0 100 fpm is
recommended.
American National Standard for Laboratory Ventilation ANSI/AIHA Z9.5-2003
3.3.1 The average face velocity of the hood shall provide sufficient capture and
containment of hazardous chemicals generated under as-used conditions.
Fume hood face velocity is often cited by
safety professionals as not (of itself) indicative
of safe fume hood containment. However,
once the average face velocity needed for
proper containment for a particular fume hood
has been determined and verified by
recognized test methods (notably the
ASHRAE 110 containment test), that fume
hood’s average face velocity can be used as
a ‘benchmark’ for safe performance as long
as other room factors (that is, air cross
currents, etc.) remain essentially unchanged.
Therefore continued measurement and
monitoring of a fume hood’s average face
velocity is a key factor in assuring continued
safe performance.
An average face velocity above 100 fpm can
create ‘eddies’ and air turbulence around the
person in front of the fume hood causing
contaminants to be pulled out of the fume
hood interior. Thus, trying to attain an
average face velocity appreciably more than
100 fpm may not improve a fume hood’s
containment, and may also worsen the
situation.
Fume hoods were previously classified by
ANSI/AIHA Z9.5 in 1992 as Class A and B
according to face velocity, but are no longer
so classified by the AIHA.
Fume hoods were also previously classified
by SEFA
in 1992 as Class A, B, and C
according to face velocity. The SEFA
organization no longer classifies fume hoods
in this way.