Food Safety Analysis, LLC


Plant Environmental Microbiological Assessment

In order to produce a microbiologically safe product, the possibility of inadvertently introducing microbes into the finished product needs to be made as low as possible. At the same time, this rather obvious step should be done in such a way as to interfere as little as possible with both the speed of the production operation and its profit-making potential. Fine-tuning microbial exposure to finished product requires knowledge of the microbial load within the manufacturing plant. This includes all facets of a manufacturing plant's operation.

As is also evident, the microbial load what exists within a plant must contribute to any HACCP plan that is developed for every product produced within that facility. Indeed, how may one even begin a hazard analysis without knowing what hazards are out there? Any extraordinary facets of the microbial load of a plant may (or may not) need to be addressed by establishing Critical Control Points. The first step therefore is a careful assessment of microbial load in such things as the incoming water as well as the outgoing drains. The microbial load that enters the plant along with the packaging materials must be assessed as well. For example, ordinary cardboard is sometimes quite laden with microbes. The load on environmental surfaces should be known as should the microbial load found on the plant machinery itself. Of course, all of these potential sources of microbial contamination contribute microbial load to and receive it from the plant air itself. This is why the measurement of microbial load in a food manufacturing environment very often turns on the microbial content of the very air itself. Of course, measurement before and after sanitation provides documented efficacy of whatever sanitation process is being used (or signals that more attention must be paid to sanitation). In addition, finding product contaminated by one or more microbes not in the plant's environment would suggest that the HACCP plan did not evaluate all possible hazards. Some understanding of the environmental microbial load must be exist before any such differential diagnosis may be attempted.

If you click on the link below entitled "MICROBIAL LOAD OF AIR EXAMPLE" you will be taken to a sample result. Before such a result may be generated, the plant area to be sampled must be carefully measured and each sampling site assigned a x,y value within the designated Cartesian space, represented as a plane (i.e., the layout of the "floor"). Each reading of microbial load obtained at each individual sampling site may then be represented as a "z-value" arising from and perpendicular to the Cartesian plane. Mathematical tools exist which are able to look at all z-values within a Cartesian plane, interpolate the best fit of a surface through them and represent the z-values observed as either a three dimensional surface or as a contour map. In this example, the data were represented as a 3-D surface plot.

As you can see, there is a broad peak of microbial load in the air in one portion of the plant. The value of this plot in this particular example is the relationship between microbial air load measured here and and the HACCP plan of this hypothetical company. This 3-D plot can be correlated to the placement and manufacturing activities of the plant itself. This company can argue that the microbial load observed is a function of the number of people who normally occupy this area, which is a packaging area only and, as such, quite busy. It is well known that people are one of the most reliable contributors of microbial contamination to the air. In this case, however, the hypothetical company can argue that their product is most vulnerable to contamination while being bottled and that, since bottling is automated, the most vulnerable activity occurs well upstream of the area most susceptible to microbial contamination. Only fully sealed bottles enter the contaminated area where packaging and shipping activity dramatically increases the microbial load of the air. Therefore, any microbial contamination noted here need not inform the HACCP plan because even hazardous microbes found in the ambient air at this point cannot be hazardous to a product inside a fully sealed bottle.


Copyright © 2012 by M. Mychajlonka, Ph. D.