ICE Chips

Q.  I have just been hired as a QA technician at a food plant. This is my first job in this position, and I will be responsible for taking the environmental samples each week. I have noticed that the previous technician always took the swab sample from the same area on the equipment. There did not seem to be any positive samples, and I am wondering if I should start swabbing other areas to make sure there are no problems. What do I do if I begin getting positives?

A. This is far too common in some plants. There are a few plants where environmental sampling is guaranteed to come back negative. However, a review of the program’s history often reveals that they were getting positive results at one time. Since the technician had to return to the same spot to ensure a negative result was attained, he or she become conditioned to returning to that spot for future samples. A pattern develops and the people cleaning begin to focus on those specific spots to guarantee they are always clean and sanitized. In some cases, the level of sanitizer in these particular locations is so high that nothing could survive!

To properly calibrate the effectiveness of the cleaning and sanitizing programs, it is very important that samples be taken at random locations within the defined zone pattern your facility has established. This also takes the predictability out of the equation so you get a better and more accurate sampling of the conditions that truly exist. It is far better to realize there is a positive sample and take immediate corrective action, than to ignore the potential and cause an illness or worse in the marketplace.

To avoid this type of pitfall, establish your protocols and set up sample zones and sampling methods you will use at each sampling site. It may be a good idea to rotate the people taking samples, if they are qualified to do so, to avoid repeating the same predictable sites. This will establish the effectiveness of your sanitation program.

If you test and get positive results in areas that could affect the integrity of the product (food-contact surface or inside the product zone) and it is positive for a pathogen, the product also has reasonable suspicion to be contaminated. The product must be withheld from the market and destroyed. At this point it would not be appropriate to sample the product to see if you get a positive from the product. Positive or negative, the product in this case must not be introduced into the market. If a sample comes back positive and is not from a food-contact surface or a product zone (lower supports or floor drain), the areas must be re-cleaned and sanitized and samples retaken to ensure the issue has been resolved.

The author is Head of Food Safety Education, AIB International.

Do you have a question for Al St. Cyr? If so, e-mail him at astcyr@aibonline.org.