airflow conforms to design criteria.
30 in. in height and 30 in. or less in width. Once the desired
water fall effect is noticed, secure the work table at that location and perform the smoke pattern test.
Performing the clean zone smoke pattern test
Purpose: This test determines that the airflow within the
clean zone conforms to the manufacturer’s design criteria.
This shows the airflow within the DCA moving in a downward direction with no dead spots or refluxing in the critical
site. Be sure that the ambient air does not enter the clean
zone or other areas except through the supply HEPA filter.
Once the air enters the DCA, it must move to the returns
without reentry. (Note: This test should be performed following
completion of the airflow velocity, volume, room air changes per
hour, room pressures, and uniformity tests.)
Apparatus: A source of visible smoke that is generally neutrally buoyant. Chemical smoke tubes or glycol-base smoke
generators are examples of acceptable smoke sources.
Good results can be achieved using a theatrical fog generator that has a mixture of glycol with a fan speed controller connected to a delivery tube, supported by a hands-free
stand (1 in. diameter PVC with small holes to create a lami-nar-like curtain smoke pattern). It is recommended that the
PVC tube be the same size as the distance between the front
shield and the wall.
• Adjustable support stand
• Plumb bob
• Tape measure
• Video or digital camera
• Place the delivery tube with the plumb bob.
• Turn on the smoke generator and adjust the fan speed-control to get the desire laminar airflow.
• Introduce the aerosol stream isokinetically and, as nearly
as practical, isothermally.
• Generate the smoke remotely from the vicinity of the
• Move the smoke tube through the entire area to be tested,
sliding the hands-free stand slowly so that the whole clean
zone area is observed and video recorded.
• With the pointer mounted in the support stand, at
the work table exit plane, measure the offset distance (Δs)
between the theoretical straight-line flow point and the
center of the source stream. Measure the distance between
the delivery outlet tube and the work table exit plane (d).
Acceptance: Readings in excess of a 14-degree offset should be
discussed with the customer and either approved or corrections made until acceptable.
The clean zone smoke pattern test needs be performed “as
built,” “at rest,” and “operational” phase.
Other tests that need be performed are: airflow volume,
airflow velocity, and uniformity test; HEPA filter leak test;
airborne particle count test; rooms pressurization test; light
level and uniformity test; noise level test; temperature uniformity test; moisture uniformity test; vibration test; microbiological sampling test and air changes per hour (ACPH)
calculations. (See IEST-RP-CC-006.3 Section 5.1 and USP 34
(1116) for details.)
1. IEST RP-CC-001.5, HEPA and ULPA filters.
2. IEST RP-CC-002.3, Unidirectional flow, clean air devices.
3. IEST RP-CC-006.3, Testing Cleanrooms.
4. United State Pharmacopeia (USP) 797, Pharmaceutical
Compounding physical test.
5. United State Pharmacopeia (USP) 1116, Microbiological
evaluation of clean rooms.
6. ISO 14644.1:1999, Cleanroom and associated controlled
7. Controlled Environment Testing Association (CETA)
CAG-003-2006, Revised Jan. 31, 2012, Sterile Compounding
Ruben Contreras is Vice President with Superior Laboratory
Services Inc., 1710 Preston Rd, Suite A, Pasadena, Texas 77503;