Basic Documentation

Table Of Contents
Laboratory Ventilation Codes and Standards
Siemens Industry, Inc. 66
Topic Requirement(s) Commentary
Ventilation
for
Biosafety
Level 3
(Continued)
American Institute of Architects, GUIDELINES FOR PLANNING AND DESIGN OF
BIOMEDICAL RESEARCH LABORATORY FACILITIES 1999
C.11.4 BL-3 b. Containment Requirements: Laboratories require all of the design
considerations for BL-2 laboratories plus specific requirements for additional
containment of those bio-hazardous materials used in the laboratory.
Ventilation must be single-pass air, and all BL-3 space must be kept negative with
respect to outside corridors and laboratories. Exhaust ducts must be under negative
pressure until the air is discharged outside the building.
Supply and exhaust ducts for BL-3 laboratories must be supplied with gas-tight
dampers to maintain the capability of gas decontamination of the laboratory without
compromising the rest of the building. Ductwork between the laboratory and the
damper must be gas tight.
n. Alarms: BL-3 facilities must be designed to ensure notification of inappropriate
directional airflows. Both visual (gauges) and audible local alarms are acceptable. In
addition, alarms indicating the potential failure of BL-3 containment shall be tied to a
central system at the Building Engineer’s office, where possible. Notification devices
shall indicate the failure to maintain a negative pressure differential between a non-
contaminated area and potentially contaminated areas.
All alarm systems shall be validated prior to occupancy of the containment space by
research personnel.
o. Filtration of Laboratory Exhaust: The need for HEPA filtration shall be
determined on a case by case basis in consultation with the facility safety personnel
and shall be based on a hazard assessment of the materials in use and the
procedures to be performed.
p. Autoclave Exhaust Filtration: The exhaust from an autoclave contains a
significant amount of moisture, and exhaust ductwork shall be designed accordingly.
Filtration of this exhaust, when necessary, (as determined above in Filtration of
Laboratory Exhaust) must be through a moisture-resistant (hydrophobic) filter such as
a 0.2 micron filter or equivalent. Filtration of moist exhaust through a cold filter
housing containing a paper HEPA filter will result in the destruction of the HEPA filter
and a break in integrity.
q. HEPA Filter Housings: When installed, HEPA filter exhaust housings must be
constructed in such a manner as allow for appropriate particulate testing (that is, DOP
or equivalent) and must be capable of being isolated from the ventilation system for
gas decontamination and testing (that is, gas-tight dampers and housings). Facility
safety personnel must be consulted with regard to the suitability of the
decontamination mechanism design and approve the system prior to finalization of
the design.
While BMBL requires sealable penetrations”
AIA specifies gas-tight dampers and ducts.