Basic Documentation

KEY:
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MS
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WS
LABORATORY ROOM
LABORATORY ROOM
LABORATORY ROOM
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A
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NO PRESSURIZATION (NEUTRAL)
SLIGHT NEGATIVE PRESSURIZATION (0.01 TO 0.05 INCHES W.C.)
INCREASED NEGATIVE PRESSURIZATION (0.06 TO 0.10 INCHES W.C.)
GREATEST NEGATIVE PRESSURIZATION (0.11 TO 0.15 INCHES W.C.)
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M
M
M
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DIFFERENTIAL PRESSURE MONITOR
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SPECIMEN ENTRY
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MECHANICAL
EQUIPMENT
ROOM
JANITORIAL &
MAINTENANCE
CLOSETS
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AUTOCLAVE
ROOM
SUPPORT ROOM
Figure 5. BSL-3 Biological Laboratory Suite–Differential Pressure Relationship
.
Air Filtration
BSL-3 laboratory supply air is not required to be
equipped with HEPA (High Efficiency Particulate Air)
filters. However, the USDA requires HEPA filters on
supply air serving animal rooms to ensure
containment upon system failure.
14
BSL-3 laboratory exhaust air is required to be HEPA
filtered except when the laboratory will only be
manipulating non-airborne transmitted organisms.
When filtering is required, it must include the room’s
ceiling and/or floor exhausts and any other exhausts
from the room such as canopy exhausts and
specialty exhausts. Even though Class II Biosafety
cabinets are equipped with HEPA exhaust air filters,
good laboratory design practice is to have all of the
Siemens Industry, Inc. Page 9 of 10
Document No. 149-997
14. A HEPA filter will effectively block airborne bacteria and
most viruses, but will not stop prions or chemical fumes.
combined exhaust from the entire laboratory room
pass through a final HEPA filter before connecting to
the facility’s exhaust system.
HEPA filter(s) located in the exhaust system
ductwork should be in bag in/bag out housings. The
filter housing should be isolated by bubble tight
isolation dampers
15
to enable decontamination of
the filter before removal. To ensure continued
operation of the laboratory while replacing filters,
dual filter exhaust housings in parallel are
recommended. Filters should be accessible from
outside of the laboratory rooms, preferably in the
mechanical equipment room
16
or in a service
15. Bubble Tight isolation dampers are normally manually
operated and do not require a remote operation provision.
16. Mechanical equipment rooms serving biological laboratories
should preferably be located close to or adjacent to the
laboratory suite and be negatively pressurized if exhaust
filters are accessible from within the room.