HYGIENE CONTROL IN THE BREWING INDUSTRY
WITH REFERENCE TO AIR PARTICLE CONTROL
Environmental monitoring in
the Food and Beverage Industry
South African Breweries
January 2012
Stephen Marrs
IEPSA
What is a particle?
A solid or liquid object which, for the purposes of classification of air cleanliness, falls within
a cumulative distribution that is based upon a threshold (lower limit) size in the range from
0.1 μm to 5.0 μm
ISO 14644-1
Why the concern about particles?
For security & quality reasons during production:
Pharmaceutical industry: particles in vaccines cause
occlusion of blood vessels
Medical devices: poor adhesion of coating in stents
creates emboli
Medical films: contamination prevents complete image
recovery
Electronic industry: particles on circuit boards create false
contacts
A PARTICLE WILL BECOME A CONTAMINANT!
THE CONCENTRATION OF PARTICLES INDICATE THE
LEVEL OF CONTAMINATION IN A CRITICAL AREA…..
Particle sizes
Diameter in micrometer (µm)
Sand:
Human hair:
Meal:
Bacteria:
Cigarette smoke:
Virus:
80 – 2000 µm
100 µm
5 – 10 µm
0,2 – 2 µm
0.01 – 1 µm
0.003 – 0,05 µm
Sources of particles?
In a cleanroom the human being
is the biggest contaminator:
Dead skin cells are discarded
continuously
Exhalation carries a mixture of
gases
In critical areas operators need
to ware cleanroom clothing
Emission of particles
Emission of particles >0,5 µm per minute
Normal Clothes Cleanroom clothes
No movement
Light movement
Going to sit
Walking
Running
Running fast
100.000
500.000
1.000.000
5.000.000
100.000
7.500.000
1.000.000
10.000.000
Sources of human particles
Standards for particle counting
• ISO 14644
General standards for all cleanrooms
Particle limits for sizes/classes
• EU cGMP
Industry specific (pharmaceutical)
More stringent levels
At rest v. operational
ISO 14644-1 air borne particle
cleanliness classes for clean rooms
Good practices for particle counting
The cleanroom layout:
the layout has to match the operational situation
the equipment will have a fixed position
overview of the different critical areas
the areas will get a proper identification: (alphanumeric) name
also the sample locations will be identified on the CR layout
both the areas and the sample location names can be set
on the counter
operators need to be trained to use the designated sample
locations to make representative samples
How many sample locations in a clean zone?
ISO 14644 – 1 has a simple formula:
√A = x, A =
surface in m²
x = minimum number of sample
locations acc. to ISO 14644-1
Sample locations are spread equidistant,
at the highest risk for contamination
A simple example for a “cleanzone” of 16 m²:
-4 locations ISO 5 @ ≥ 0.5 micron
-Class limit is 3520 particles/m³
After revision 14644: 8 sample locations!!
Position of the Isokinetic probe
Designed to sample air with a nominal velocity of 0,5 meters per sec
Pointing into the airflow at the sample location
Vertically upward if direction of the airflow is unknown
Environmental measurements: at a height of 1,5 meter and upward
In a process measurement: in the work field of the operator to monitor
the risk for contamination
Check the probe on deformations and cleanliness:
-a stainless steel probe is more robust
-autoclavable
The zero count filter
Will hold particles bigger than 0,2 µm
Easy tool to check the proper working of the counter:
-less than 1 count in 5 samples of a minute
-repeat the test on a regular basis, once per week
Second function of the filter: to purge the counter
-if you go from a ISO 9 Class to a ISO 5
do a purge action to start with a clean optical system
How does a particle counter work?
There are three basic elements in all particle counting systems:
1) The sensor
The sensor is the device that detects particles using
a light scattering method of detection.
2) The sample delivery system
The sample is delivered to the sensor by the use of
a vacuum system.
3) The counting electronics
The particle counts are processed and displayed
on a screen.
Optical System Cross-Section
Biotest solutions
Handheld Particle Counter
•
•
•
•
•
Easy and safe operation
Individual Channels 0,3µm - 10µm
10.000 records stored in memory
Windows CE & USB connection
Ideally suited for monitoring Processes
and filters
Thank you