Basic Documentation

Siemens Industry, Inc. Page 5 of 8
Document No. A6V11520001
Room Exhaust
Return openings from the room should be low on the
walls
3
, to promote a downward flow of air from the
supply to return, sweeping contaminants to the floor
and away from the product. Perforated floors are not
recommended due to the difficulty in cleaning them.
The room exhaust should be sized to handle both
the room and all containment devices vented
through the system.
Room Pressurization
Pressure gradient is used to minimize particle
migration into the clean space from a less clean
space. Since the buffer area is required to be at a
negative pressure to protect personnel outside the
space, the ante-room is required to be at the same
level of cleanliness (ISO Class) as the buffer room.
When the door is opened, there will be a cascade or
flow from the ante-room to the buffer room.
To ensure minimum air changes, the supply airflow
volume must be compensated for filter loading.
Differential Pressure (D/P) Monitoring–A pressure
gauge or velocity meter must be used to monitor the
pressure differential or airflow between the ante-
area and the buffer area and between the ante-area
and the general environment (corridor or pharmacy).
This gauge or meter allows the pressurization to be
constantly monitored and provides a visual
indication of the direction of airflow to the healthcare
workers. It lets them know that the required room
pressurization is being maintained and warns them
of any loss of the required D/P. A momentary loss in
D/P occurs when a door is opened and then closed.
Therefore, D/P alarms should have an adjustable
delay period to prevent nuisance alarms during the
time needed for normal passage through the
doorway and for the ventilation system to restore the
required D/P.
3. ASHRAE Handbook 2003, Chapter 16 Clean Spaces
Temperature and Humidity
Maintain the temperature below 68°F (20°C) and the
humidity below 60% in the CSP compounding area.
Maintain humidity and temperature at a level
necessary for operator comfort in the C-SEC
designated for the preparation of CNSPs.
Temperature and humidity must be controlled
through an efficient HVAC system.
Air Changes
The required rate of air changes is dictated by the
internal generation of particles from operators and
building elements such as walls, ceiling, floor, and
so on.
The ISO 7 buffer room and ISO 7 ante-area must
maintain an ACPH value of not less than 30. The
ACPH of 30 can include recirculated HEPA-filtered
air, but at least half of the ACPH must be HEPA-
filtered fresh air.
The C-SEC for CNSPs and the C-SEC for category I
CSPs must maintain an ACPH value of not less
than 12.
Monitoring and Alarms–The International Society
for Pharmaceutical Engineering (ISPE) guidelines
state that critical parameters that can affect CSP
quality must remain within process limits and should
have alerts and alarms. The following critical room
conditions should be monitored to document
cleanroom environmental conditions:
• Room temperature
• Room humidity
• Room D/P
• (Optional) Particle count
Audible and visual indication of cleanroom alarms
should be provided for healthcare workers, and the
time of the alarm should be recorded. Integration of
HVAC controls into the BAS allows historical data,
alarms, and alarm acknowledgements to be
collected and archived in order to document
compliance with regulatory requirements.