Basic Documentation

Table Of Contents
Laboratory Ventilation Codes and Standards
Siemens Industry, Inc. 42
Topic Requirement(s) Commentary
Monitoring
National Fire Protection Association, Standard NFPA 45, 2011
8.8.7 Measuring Device for Hood Airflow. A measuring device for hood airflow shall
be provided on each chemical fume hood.
8.8.7.1 The measuring device for hood airflow shall be a permanently installed device.
8.8.7.2 The measuring device for hood airflow shall provide constant indication to the
hood user of adequate or inadequate hood airflow.
American National Standard for Laboratory Ventilation ANSI/AIHA Z9.5-2003
3.3.3 All hoods shall be equipped with a flow-indicator, flow alarm, or face velocity
alarm indicator to alert users to improper exhaust airflow. The flow-measuring device
shall be capable of indicating airflows at the design flow and ±20% of the design flow.
The device shall be calibrated at least annually and whenever damaged.
Scientific Equipment & Furniture Association
SEFA 12006 Recommended Practices for Laboratory Fume Hoods
4.1.10 Hood Monitor
All hoods shall have some type of monitor for indicating face velocity or exhaust flow
verification. The monitor can be a simple pressure gage connected to a Pitot tube in
the exhaust duct, one of many electronic monitors, or a vane anemometer.
Regardless of the monitor installed, it should provide clear indication to the hood user
whether exhaust flow or face velocity is within design parameters.
A ribbon taped to the bottom of the sash is not acceptable.
ASHRAE, 2011 Handbook - HVAC Applications, Laboratories, Pg. 16.18, Operation
and Maintenance:
Centralized monitoring of laboratory variables (e.g., pressure differentials, face
velocity of fume hoods, supply flows, and exhaust flows) is useful for predictive
maintenance of equipment and for ensuring safe conditions
California OSHA Division of Occupational Health & Safety (DOSH) Subchapter 7.
General Industry Safety Orders, Group 16. Control of Hazardous Substances,
Article 107. Dusts, Fumes, Mists, Vapors and Gases
5154.1. Ventilation Requirements for Laboratory-Type Hood Operations:
By January 1, 2008, hoods shall be equipped with a quantitative airflow monitor that
continuously indicates whether air is flowing into the exhaust system during operation.
The quantitative airflow monitor shall measure either the exact rate of inward airflow or
the relative amount of inward airflow. Examples of acceptable devices that measure
the relative amount of inward airflow include: diaphragm pressure gauges, inclined
manometers, and vane gauges. The requirement for a quantitative airflow monitor
may also be met by an airflow alarm system if the system provides an audible or
visual alarm when the airflow decreases to less than 80% of the airflow required.
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notified if the fume hood is not operating
properly. This mainly occurs due to a face
velocity that is too low or too high, or if there
is insufficient minimum exhaust airflow when
the sash is closed. Maximum user protection
is achieved by providing both a visual and an
audible annunciation of improper fume hood
airflow conditions. In addition, fume hood
airflow alarms that also report at a designated
location (such as on the facilitys ventilation
control and monitoring system) provide added
assurance that unsafe conditions will be
reported and those responsible for
maintaining safe laboratory conditions will
take appropriate action.