Basic Documentation

Table Of Contents
Laboratory Ventilation Codes and Standards
Siemens Industry, Inc. 94
Topic Requirement(s) Commentary
Biosafety
Cabinet
Testing
(Continued)
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
5154.2. Ventilation Requirements for Biological Safety Cabinets
(f) Airflow measurements and HEPA filter leak testing. Biological safety cabinets shall
be tested after installation, alterations, or maintenance, and at least annually.
Records of tests performed shall be retained for at least five years.
(1) The ventilation test requirements for Class I biological safety cabinets are as
follows:
(A) Velocity measurements shall be made at the work opening of the cabinet with a
calibrated anemometer.
(B) 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.
(C) 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.
(2) The ventilation test requirements for the Class II biological safety cabinets are as
follows:
(A) For type A and B3 cabinets the average intake face velocity at the normal
operating work access opening shall be determined by measuring the exhaust air
velocity, calculating the cabinet's exhaust air volume, and dividing this volume by the
open area of the work access opening. Average face velocity is calculated by the
following equation: (average exhaust velocity X open area of HEPA filter or exhaust
port) / (area of normal work access opening) = average face velocity.
Exception: Cabinets in which the exhaust filter is not accessible can 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.
(B) For type B1 cabinets the average intake velocity shall be determined by directly
measuring the inflow velocity at the normal operating work access opening with the
cabinet recirculating blower turned off. A calibrated total captured airflow hood may
be used for type B1 cabinets as in (A) above.
(C) For type B2 cabinets the average face velocity shall be calculated based on total
exhaust air volume (velocity measurement at exhaust port), supply airflow volume,
and work access area. Average face velocity is calculated by the following equation:
[(average exhaust velocity X area of exhaust port) - (average supply downflow
velocity X open area of supply HEPA filter)] / (area of normal work access opening) =
average face velocity.
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