SUBJECT Consultative Letter, AFRL-SA-BR-CL-2009-0035, Annual

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SUBJECT Consultative Letter, AFRL-SA-BR-CL-2009-0035, Annual Powered By Docstoc
					                                 DEPARTMENT OF THE AIR FORCE
                               KADENA AIR BASE JAPAN

                                                                                     16 April 2009

               Unit 5071
               APO AP 96328-5071

      Unit 5213, Box 10
      APO AP 96368-5213

SUBJECT: Consultative Letter, AFRL-SA-BR-CL-2009-0035, Annual Certification Survey of a
         Biological Safety Cabinet, 374 MDSS Medical Laboratory, Yokota AB, Japan

1. Executive Summary: On 23 February 2009 personnel from Detachment 3, United States
Air Force School of Aerospace Medicine (Det 3, USAFSAM) completed an annual certification
survey on a Labconco Purifier Model 36204 Biological Safety Cabinet (BSC), Class II, Type A2.
This BSC is part of the 374 MDSS Medical Laboratory Services Home Station Medical
Response (HSMR) Laboratory. The BSC was field certified in accordance with the references
listed in paragraph 2.c. The BSC passed all tests and is certified for one year. The cabinet must
be re-certified if it is moved to another location. Certification data is provided as an attachment.

2. Background: This BSC is designated to be used for biological warfare agent testing and
therefore is located in an isolated room within the hospital (room is accessible only from the
exterior of the building). Class II, Type A2 BSCs contain two high efficiency particulate air
(HEPA) filters (downflow and exhaust). This cabinet is designed to provide personnel, product
and environmental protection from biohazardous particulate matter. Type A2 BSCs are designed
to exhaust directly to the room. The HEPA filters will not capture chemical vapors, so the
cabinet is not suitable for the use of chemicals that may produce hazardous vapors. The
information listed below identifies key personnel contacted and certifying data used for the

    a. Personnel Contacted (374 AMDS and 374 MDSS):
       (1) MSgt Duane Restivo, NCOIC, Laboratory Services
       (2) TSgt Jamie Disney, Laboratory Technician

    b. Certifying Personnel (Det 3, USAFSAM):
       (1) TSgt Mark Atwood, NCOIC, Consultant Division
       (2) SSgt Penelope Harrison, Bioenvironmental Engineering Technician

Distribution A: Approved for public release; distribution unlimited
   c. References:
      (1) Labconco User’s Manual (2007), Purifier® Delta Series Biological Safety Cabinets,
          Models 36204/5/8/9 and 36212/3 Series
      (2) NSF 49 International Standard (1992), Class II (Laminar Flow) Biohazard Cabinetry

                                                      Purifier Biological Safety Cabinet

                                                      Model: 36204-04
                                                      Serial Number: 020320880Z
                                                      Classification: Class II, Type A2

                                                      This unit is located in HSMR Laboratory,
                                                      Bldg. 4408, Rm C021.

Figure 1. Labconco Purifier Biological Safety

3. Survey Protocol: The operational certification protocol included the following parameters:

    a. Cleaning and Disinfecting the BSC Work Surface: The owner of the BSC cleans and
disinfects surfaces prior to our arrival. Det 3, USAFSAM personnel perform a final disinfection
with 70% (or stronger) alcohol solution.

    b. Downflow Velocity Profile Test: The laminar downflow captures any aerosol generated
in the work area of the cabinet and directs it to the HEPA filters. In order to be true laminar
downflow, the individual test points must be within 16 feet per minute (fpm) or ± 25% of the
average of all test points. The manufacturer requires the downflow velocity to be 55 ± 5 feet per
minute (fpm). We established a grid to measure the downflow air at 21 points in accordance
with manufacturer recommendations. Reference the attachment for details.

    c. Inflow Velocity Profile Test: Inflow consists of air drawn into the front of the cabinet at
the front grille. This "curtain" of air makes it more difficult for aerosols to escape out of the
work area of the cabinet and into the outside environment. We used the constricted access
opening method to determine average inflow velocity at normal sash operating height. The
manufacturer’s inflow velocity requirement is 105 ± 5 fpm.

    d. Magnehelic Gauge: The magnehelic gauge located on the front cover of the cabinet
provides an indication of HEPA filter loading. According to the manufacturer, when filters are
clean (minimal loading), the magnehelic gauge will read between 0.8 – 1.1" H2O. The
manufacturer recommends recertification whenever the readings change more than 20% in either

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direction to verify the airflow velocities are sufficient. An increase in the pressure typically
signifies the filter is loading with particulates. A significant drop in pressure (>20%) reading
typically indicates a hole in one of the HEPA filters which can produce an unsafe environment.

     e. HEPA Filter Leak Test: To evaluate filter leakage, an aerosol concentration is generated
inside the enclosure and each HEPA filter is surveyed at the filter (with diffuser panels removed)
using a photometer. The leak test is performed to ensure the air passing through each of the two
HEPA filters meets the particle penetration acceptance criteria of less than or equal to 0.01% of
the challenge concentration at any point. Overlapping passes are made to ensure complete
coverage. Photometer readings above 0.01% at any point indicate leakage, which may require
filter replacement. Due to the sensitivity of the filter material, only personnel qualified to certify
biological safety cabinets should replace the HEPA filters. After filter replacement, and prior to
resuming usage, the BSC must be re-certified.

    f. Airflow Smoke Patterns Test: We conduct smoke tests to ensure the direction of air
movement is consistent throughout the face opening of the hood and potentially contaminated air
is not leaving the enclosure to enter the room.

4. Findings and Discussion:

   a. Cleaning and Disinfecting the Bench Work Surface: We wiped the interior surfaces
down with Rugby alcohol prep pads (70% isopropyl alcohol).

    b. Downflow Air Velocity Profile: We measured and calculated the average downflow air
velocity for the BSC at 59 fpm. The manufacturer requires the downflow velocity to be 55 ± 5
fpm. All of the readings were within 16 fpm or 25% of the average value, indicating laminar
flow. Therefore, this enclosure adequately meets manufacturer requirements for downflow
velocity. The attachment illustrates the grid profile and individual values.

    c. Inflow Air Velocity Profile: The average constricted opening air velocity for the BSC
was 253 fpm. From this, the calculated inflow velocity was 108 fpm. This meets the
manufacturer’s inflow velocity requirement of 105 ± 5 fpm. The attachment illustrates the grid
profile and individual values.

   d. Magnehelic Gauge: The magnehelic gauge reading was 1.00" H2O. This meets
manufacturer requirements.

   e. HEPA Filter Leak Test: We generated 41 micrograms per liter (µg/L) of aerosol to
evaluate filter leakage. We detected no leaks in the downflow and exhaust HEPA filters.

   f.   Airflow Smoke Patterns Test: There were no discrepancies with the smoke tests.

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5. Conclusions: We certified this BSC for one year and scheduled the next survey for February
2010. Affixed to the front of the BSC is a current certification label. Please note, if you move or
make any other significant changes to this cabinet, you must have the BSC re-certified out of cycle.

6. We would like to thank all personnel involved for accommodating our survey schedule. Please
contact SSgt Harrison (DSN 634-2597 or email ) or myself (DSN
634-0786 or email ) for any questions.

                                             MARK A. ATWOOD, TSgt, USAF, OHST
                                             NCOIC, Consultant Division

Certification Data


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