Basic Documentation

Laboratory Ventilation Codes and Standards
Siemens Industry, Inc. 100
Topic Requirement(s) Commentary
Ventilation
Rates for
Chemical
Laboratories
Local Codes
Some local jurisdictions may impose other specific ACH requirements for biological
laboratories (that is, UBC requires six ACH)
ASHRAE, 2011 Handbook - HVAC Applications, Laboratories, Pg. 7.6, Health
Care Facilities:
Radiology 6 ACH with 2 ACH from Outside Air Bacteriology, Biochemistry,
Pathology, Serology, etc.: These labs requires a minimum ventilation rate of 6 ACH
with the equivalent of 1/3 of the ventilation air (2 ACH) consisting of outside air.
American National Standard for Laboratory Ventilation ANSI/AIHA Z9.5-2003
2.1.2 The specific room ventilation rate shall be established or agreed upon by the
owner or his/her designee.
2.1.3 The general ventilation system shall be designed to replace exhausted air and
provide the temperature, humidity, and air quality required for the laboratory
procedures without creating drafts at laboratory chemical hoods.
2.1.4 Dilution ventilation shall be provided to control the buildup of fugitive emissions
and odors in the laboratory.
U.S. OSHA, 29 CFR, Part 1910, Occupational Safety and Health Standards,
Subpart Z, Toxic and Hazardous Substances,1910.1450,C4(f):
4-12 room air changes/hour is normally adequate general ventilation if local exhaust
systems such as hoods are used as the primary method of control.
National Fire Protection Association, Standard NFPA 45, 2011
A.8.2.2 Laboratory units and laboratory hoods in which chemicals are present shall
be continuously ventilated under normal operating conditions.
ASHRAE, 2011 Handbook - HVAC Applications, Laboratories, Pg. 16.8
LABORATORY VENTILATION:
The total airflow rate for a laboratory is dictated by one of the following:
• Total amount of exhaust from containment and exhaust devices
• Cooling required to offset internal heat gains
• Minimum ventilation rate requirements
Minimum ventilation rates should be established on a room by room basis
considering the hazard levels of materials expected to be used in the room and the
operation and procedures to be performed.
Local Codes
Some local jurisdictions may impose other specific ACH requirements for chemical
laboratories (that is, UBC requires six ACH).
Specific requirements for the ventilation rate of
biological laboratories vary somewhat or in
many cases are established by the facility’s
own health and safety standards.
Note that in order to ensure that the proper
ventilation rate is in effect, a means of
measuring and continuously monitoring room
exhaust airflow is necessary
The AIHA stresses that the necessary
ventilation rate depends on the particular
hazards and that one rate does not suit all
situations.
Although regulatory agency and published
standards allow lower ventilation rates, current
ventilation system designs for chemical
laboratories typically utilize 10 to 12 air
changes per hour (ACH) for an occupied
laboratory. During unoccupied times the
ventilation rate may be reduced to 4 ACH and
still comply with national codes and standards,
although some local codes may require 6 ACH.
Note that a minimum airflow must be
maintained through each fume hood even when
the fume hood sash is fully closed (See Fume
Hoods: Minimum Exhaust). In some labs it is
not possible to reduce every laboratory room’s
ventilation rate down to 4 ACH and still provide
sufficient makeup air for the room’s fume
hoods.
In order to ensure that the proper ventilation
rate is in effect, a means of measuring and
continuously monitoring room exhaust airflow is
necessary.
Ventilation
rates for
Storage
areas
National Fire Protection Association, Standard NFPA 30, Flammable and
Combustible Liquids Code, 2000, Liquid Storage Areas:
Mechanical ventilation systems shall provide at least 1 cfm per sq. ft. but not less
than 150 cfm for storage rooms.
For a room having over 150 square feet of area
and with a 10-foot ceiling, 1 cfm per square foot
equals 6 ACH.