AboutCarol Schlitt Expertise I can answer questions on home food safety, sanitation, home food preservation and commercial food safety (HACCP).
Experience I am an Extension educator, nutrition, wellness and food safety. I am a certified HACCP manager and a food safety instructor for the Illinois Department of Public Health.
Organizations International Association for Food Protection, American Association of Family and Consumer Sciences (Certified CFCS), National Extension Association of Family and Consumer Sciences, Society for Nutrition Education.
Education/Credentials BS - University of Illinois
MS - Southern Illinois University at Edwardsville
Question Many years ago I took several courses in microbiology. the conclusion at the time was that for most foods the time it takes to develop a large enough population of bacteria to be harmful if ingested is 24 hours. and even this is usually destroyed by cooking again. I am not talking about freshness just the realistic probability of being harmed by food. Seems to me that a lot of food is thrown out unnecessarily. Also so many foods contain preservatives that diminish this further. i JUST WONDER HOW MUCH FOOD SAFETY IS REAL AND HOW MUCH IS FOOLISH RULES OF "THUMB". tHANKS, SAM
Answer Hi Sam,
This is a very good question that I'll try to answer.
Since we don't have 100% accuracy on predicting if a food WILL make you ill, we tend to error on the side of caution and advise consumers to not ingest foods that MAY be harmful. Remember we live in a litigious society and that fact tends to make us food safety professionals very cautious of advising individuals on the safety of consuming foods that have the potential for causing illness. Without expensive lab tests, we cannot say with absolute certainty that a particular food will not make a person ill. So we have general guidelines that have been accepted as the parameters for safety.
Now...are these guidelines "foolish rules of thumb?" Frankly -- some are not based on true science but generally accepted practice. Dr. O. Peter Snyder, founder and director of the Hospitality Institute of Technology and Management is a great example of a pioneer in food safety that continually challenges many of the current rules established by FDA and USDA. For example, the current FDA rule for restaurants is that hot food must be cooled within 6 hours from 140 to 41 degrees F. Dr. Snyder has shown that this is very difficult standard to accomplish, harder to verify that it has been accomplished and lastly is not based upon hard science but rather a generally agreed as safe guideline. His research shows that cooked hamburger can be safely cooled in a refrigerator within 15 hours and be safe. However -- as I mention again, the current litigious society we live in makes us error on the extreme side of caution -- we just can't give a blanket statement that when food handled outside of the guidelines are always safe.
For example, just yesterday a question on this same forum was from a lady who had discovered 15 jars of 14 year old home-canned tomatoes in her newly purchased (used) home. She indicated that the tomatoes looked good and that the seals on the jars were tight. Her question was "are these tomatoes safe to use in cooked products or should I throw them out?" If you read the response I gave her you'll see that from the description she gave and the general rules for evaluating the safety of old home canned products that the tomatoes are probably safe to eat. HOWEVER, home canned products change in quality over time and the products MAY have flavor and texture changes and thus we recommend not consuming the products. Also, she did not know the procedures used to can the tomatoes and procedures have changed in the past 15 years. I was covering myself liability-wise as I can not guarantee with 100% accuracy that these tomato products are safe and I can not afford the liability if she became ill from these tomatoes and decided to sue me because I told her they were safe. However -- I gave her the criteria for judging the relative quality and safety of the food and she can decide the level of her risk.
So to answer your question honestly I'd have to say some of the current rules are not based on hard scientific data but generally recognized as safe parameters. But stick around, researchers are providing valuable information every day that is slowly changing the generally recognized as safe parameters.
For more information on Dr. Snyder and his work, please see his website: http://www.hi-tm.com/
Thanks for a great, mind-stretching question.
Carol C. Schlitt
Extension Educator, Nutrition and Wellness
University of Illinois Extension
