Food Safety Magazine, October/November 2008

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 movement.

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.