for example, may inadvertently escape
from waste disposal and sewage. This
level of containment also includes
such practices as handwashing and, in
some critical situations, taking a
shower before starting work or going
from contaminated to clean.
Dilute — It has often been said that
“Dilution is the solution to pollution.”
Danger from contaminants may be reduced with volume air flow. Air movement, when used with frequent air
exchanges and filtration, is part of dilution and is quite effective in contamination control. Additionally, air filtration is
a form of confinement, particularly
when high efficiency particulate air filters are used. Likewise, directional airflow is also used as a confinement
strategy. Single-pass air from clean to
contaminated areas will prevent the
movement of droplet nuclei from their
point of generation to the final product.
Filtration and air directionality effectively augment dilution.
Decontaminate — Contaminated surfaces and materials may be decontaminated by a variety of physical and
chemical means. The methods used for
decontamination should be specific for
the target infectious organism. Consider
practicing Integrated Cleaning and Measurement, a way of assessing the use of the
right product for the application. This
means integrating the chemicals, tools
and other factors in the cleaning arsenal
to the surfaces to be cleaned, to the soiling to be removed and to the techniques
used by the cleaning staff before measuring outcomes. Assessing the effectiveness
of the application to the outcome is an
excellent way to determine its cost-effec-tiveness. We now have relatively inexpensive and user-friendly ATP-monitoring
technologies that provide us with real-time comparisons and can guide us in our
cleaning and decontamination efforts.
Communicate — When all applicable
containment and control measures are
outlined and communicated to all personnel involved, a workable contamination control program will result. Every
employee should clearly understand
what they may and may not do in their
regular course of work, and what to do
when inadvertent incidents occur.
All this stuff is fairly heady. And, I’m
the first to concede that engineered alternatives may not be a factor in our operations or even necessary until the
regulations catch up with the science.
However, bioaerosols are a risk factor in
food safety and should not be overlooked. Having said this, there are several preventive measures that are
pertinent to the food environment and
should be considered by both operators
and regulators alike. These factors were
listed in a 2004 article that appeared in
the Journal of Food Science. Parenthetically,
they make a lot of sense.
Doors — Keep them closed as much as
possible. This will help maintain air balance and prevent fluctuations in temperature and humidity—both factors in
microbial survival. Closed doors also
control employee traffic.
Traffic — People transport microbes.
The greater the traffic, the higher the
level of contamination. Restricting
movement will help to reduce risk of
cross contamination by bioaerosols.
Ventilation — Keep all mechanical
systems well maintained and in good
operating condition. As mentioned
above, air movement and directionality,
pressure gradients, dilution and filtration are integral to reducing bioaerosol
Ambient temperature and humidity –
Keeping a production area cool and dry
will reduce the number of viable droplet
nuclei in the air. It also serves to minimize any influence from the outdoor environment in critical areas.
Processes — Keep a critical eye on all
processes for the generation of aerosols.
Try different ways to minimize contamination from droplets and droplet nuclei
releases by adjusting times, interposing
barriers or altering the way foods are
handled. We are limited only by our imagination and creativity.
Forensic sanitarian Robert W. Powitz,
Ph.D., MPH, RS, CFSP, is principal consultant and technical director of Old Saybrook,
CT-based R. W. Powitz & Associates.
Contact him directly at Powitz@sanitar-ian.com or through his website at
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