Basic Documentation

Table Of Contents
Biological Laboratories
Siemens Industry, Inc. 95
Biosafety
Cabinet
Testing
(Continued)
Exception: Average intake velocity can also be measured directly at the work access
opening using a calibrated total capture air flow hood to measure the air volume
entering the cabinet, and dividing this measurement by the area of the work access
opening to determine the average face velocity.
(D) A quantitative aerosol challenge test shall be performed on each high-efficiency
particulate air filter. The test must be capable of detecting penetrations exceeding
0.005% of particles 0.3 micrometers or larger while the cabinet is in normal operation.
Any measurement exceeding 0.03% penetration shall establish a failure of the test.
Appendix A contains a recommended high efficiency particulate air filter test protocol.
(E) The ability of the hood to maintain an inward flow as required by subsection (e)
above shall be demonstrated using smoke tubes or other suitable qualitative
methods.
(3) The ventilation test requirements for Class III biological safety cabinets are as
follows:
(A) The airflow through the Class III biological safety cabinet shall be determined by
measuring the exhaust velocity at the exhaust port. Total air volume is calculated by
the following equation: (exhaust velocity) X (area of exhaust port) = total air volume.
The air change rate for a class III biological safety cabinet shall be a minimum of 1 air
change in 3 minutes or airflow required to maintain flammable gases/vapors below
20% of the LEL whichever is greater. The measurement of the negative pressure
inside the cabinet shall be made with a calibrated gauge. The accuracy of the gauge
shall be +5% at the required 0.5 inches of water gauge.
(B) A quantitative aerosol challenge test shall be performed on exhaust HEPA filters.
The test must be capable of detecting penetrations exceeding 0.005% of particles,
0.3 micrometer or larger while the cabinet is in normal operation. Any measurement
exceeding 0.03% penetration shall establish a failure of the test. Appendix A contains
a recommended high efficiency particulate air filter test protocol.
(g) Special requirements.
(1) All test or maintenance activities requiring access to potentially contaminated
interior spaces of the cabinet shall be performed after appropriate decontamination.
(2) A warning placard shall be placed on the front of the cabinet requiring
decontamination prior to opening any service panel or other interior access.
(3) Where biological safety cabinets are attached to external duct systems with a
blower and the cabinet system also contains a blower, or where the cabinet uses an
external blower, an audible and visual alarm system to alert the user indicating the
loss of exhaust flow in the external duct shall be used. Biological safety cabinets
which are served with a canopy or thimble connected exhaust system shall have a
ribbon streamer or like device attached to the edge of the canopy or thimble to
indicate the direction of flow and are exempt from the requirement for flow alarms.