Tag Archives: 5 second rule

What to do when the turkey hits the floor

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Long-time friend of the barfblog.com and fellow WKRP groupie, Michéle Samarya-Timm, MA, HO, MCHES, REHS (right, exactly as shown) of the Somerset County Department of Health — Jersey represent – has once again contributed her Thanksgiving thoughts, which are shared below. Michele is one of the thousands of front-line public health folks who do a great – and largely thankless —  job in spite of frequent silliness from political overseers.

micheleFood. It’s the focal point of any celebratory gathering – birthdays, barbecues, parties, holidays — and often necessitates a fair amount of activity before the culminating moment of actual eating.  No doubt about it, planning, purchasing, preparing and serving a family feast takes a copious amount of physical and emotional energy when striving to assure a picture-perfect event for all.   In the hierarchy of meaningful meals, Thanksgiving may just be the poster-child of a culinary Everest.  It’s a family event that memories are made of…especially when things go wrong.

Picture this:  you are preparing a beautiful 20-pound bird, in hopeful anticipation of a Norman-Rockwell moment, where everyone around the Thanksgiving table will “oooh” and “ahhh” at your culinary prowess – when suddenly, and in slow motion, the turkey falls to the kitchen floor and masterfully executes an Olympic-style slide across the linoleum in a smearing trail of poultry juices.  You stand there, a witness to the carnage, in a speechless (or expletive-driven) moment of WTF…followed by the OMG rush of “what do I do now?”

How one addresses such a surreal moment and its potentially disastrous aftermath (your in-laws are in the next room after all), is reasonably predicated on your Martha-Stewart-like creativity or knee-jerk responsiveness. Turkey disasters are such common and comic occurrences that kitchen fiascos have been fodder for Thanksgiving themed sitcoms throughout the past few decades.   If you find need for a little humor these days, turn to classic TV,  to digest the Thanksgiving food-handling practices in such shows as Mad About You, Everybody Loves Raymond, and Friends.

However, in the real world, how does one handle a turkey-hit-the-floor occurrence?

If the turkey is raw, wash off any crumbs, pet hair, or visible dirt that the moist skin has picked up Continue with fully cooking the turkey, and verify safe cooking using a probe food thermometer. As oft quoted by food safety expert Larry Pong, even poop cooked to 165 degrees F is safe to eat!  Follow up by judiciously washing and sanitizing the sink and any surrounding areas that might be contaminated by wash spray.

If cooked turkey hits the floor – well, that’s another story.   The widely cited 5-second rule is an old-wives tale.  The USDA’s Consumer Advisor “Ask Karen” recommends consumers discard food that falls to the floor or comes in contact with unclean surfaces, and goes on to note that food can be contaminated as soon as it touches the floor or dirty surfaces.  There is no scientific evidence that proves food is safe from bacteria, viruses and parasites if it stays on the floor for less than five seconds.   This has been corroborated by Don Schaffner and the food safety researchers at Rutgers who found the ‘five-second rule’ is a significant oversimplification of what actually happens when bacteria transfers from a surface to food, as bacteria can contaminate instantaneously. Rutgers identified that the amount of moisture present, the type of surface, and how long the food is actually on the floor all contribute to cross-contamination and the potential for foodborne illness.

tdy_tren_fails_151126-nbcnews-ux-1080-600Decisions, decisions.  You could cut away the contaminated section.  You could return the bird to the oven for recooking, an additional germ-killing step, assuring the surfaces contaminated are heated to greater than the safety-threshold of 165 degrees F.  (You can’t over-cook a turkey – that’s what gravy is for!)   You could discard the contaminated food.  Or you could just focus on eating the sides.   Regardless, come clean by advising your guests – food contamination, and food safety should not be kept a secret.

At the crux of it all, in your home, you are the one in charge of deciding if you want to eat or serve dirty food.   Many folks, not understanding the risks, will.   Consider however, those who are very young, very old, or immunocompromised as they are all at higher risk of getting sick.   Do you really wish to chance it?   No one intends to cause Thanksgiving Day food disasters, so be careful in the kitchen, and follow the core steps of Clean, Separate, Cook, and Chill.   A little fore-thought and care can avoid the worst.

Perhaps the ultimate of all turkey disasters was brought to us in Turkeys Away, a classic episode of WKRP, a 1970’s era sitcom about Cincinnati-based radio station, with an eccentric cast of workers.   The well-meaning, but clueless Station Manager arranges his own Thanksgiving Day promotion, to a disastrously comedic conclusion for everyone — especially the turkeys.  It’s worth a view, its worth the laugh, and may just help foster food-safe Thanksgiving memories for years to come.

As God is my witness, I will cook my turkey to 165F!

Michéle Samarya-Timm is a public health educator with Somerset County (NJ) Department of Health.  She is a champion for handwashing, food safety and getting agencies to communicate food safety in a language everyone can understand.

samaryatimm@gmail.com

‘It depends and it’s complicated’ Schaffner on the 5-second rule

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Friend of the barfblog.com shares his thoughts about the five-second rule, peer-reviewed research, and media attention. Thanks for doing this, Don.

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In March 2014 I got angry. I saw an article in the popular press indicating that researchers from Aston University in the United Kingdom had “proved the five second rule was real”  It was not the finding that made me angry as much as the science behind it. Or more properly the lack of science behind it.

don-schaffner-214x300We’ve been studying microbial cross-contamination in my lab for more than 15 years, and I have considered myself a quantitative food microbiologist for my entire career. Given those two observations, it’s only natural that I be interested in an article like this. But when I reached out to the University for more information I learned the research had not been peer-reviewed, and the best that they could offer was a PowerPoint presentation. A PowerPoint presentation is not science. Science proceeds through peer review. Like democracy it’s a terrible system, just the best one we have found so far.

After I got angry, I got busy.  And like any good professor by “got busy”, I mean that a graduate student got busy doing the actual  work of science.  I had a brand-new MS student starting in my lab, and she had funding from another source, but needed a research project. We worked together to design an appropriate series of studies that would advance our understanding of microbial cross-contamination while at the same time could generate a press release that might get a little bit of attention. Like any good scientists we built on the work of others. We acknowledged non-peer-reviewed work from other institutions that paved the way like high school student Jillian Clarke in Hans Blaschek’s lab at the University of Illinois. We also acknowledged the first peer-reviewed research from Paul Dawson’s lab at Clemson University.

Flash forward a couple of years, we submitted our article to one of the best journals out there that publishes food microbiology research, Applied and Environmental Microbiology and after peer review and appropriate revisions our article was accepted for publication.  I reached out to a colleague in the media relations department at Rutgers University, and we worked together to write a press release.

As you may have noticed, we have garnered extensive media attention with thousands of articles published around the world. The New York Times did a particularly nice piece interviewing me as well as my colleague Bill Hallman, and barfblog’s Doug Powell.  It has been a fun ride, but I’m looking forward to getting back to other things.  Just keeping up with the requests for interviews has been almost a full-time job, I have generally resisted the temptation to respond to commenters on the Internet, who complain about everything from the waste of grant funds (not the case, we used discretionary funds I raised myself), to suggestions that I studied the wrong thing.

But before we close the books on this one, I do want to respond to Aaron Carroll, a medical doctor who became interested in the topic when he co-authored a book on medical myths. Carroll insists that it’s not any of the factors we studied that are important, but rather how dirty the surface might be.  He is certainly correct in that the level of contamination, as well as the type of contamination are important (pro tip: coliforms don’t make us sick), but the degree to which those microbes transfer is also essential in determining risk. As I’ve said in many interviews, if there are no pathogens present on the surface, the risk is zero. The immune state of the person doing the eating also makes a difference. The risk for someone who is immunocompromised is higher than the risk someone who has a healthy immune system.

schaffner-facebook-apr_-14So as any listener to our food safety podcast will know, it turns out “it depends” and “it’s complicated.” The level of contamination, the type of contamination, the nature of the surface, the nature of the food, as well as the immune state of the person all matter in determining risk of eating food off the floor.

Longer contact times increase cross-contamination of Enterobacter aerogenes from surfaces to food

Applied and Environmental Microbiology; Appl. Environ. Microbiol. November 2016 vol. 82 no. 21 6490-6496

Robyn C. Miranda and Donald W. Schaffner

http://aem.asm.org/content/82/21/6490.abstract?etoc

Abstract

Bacterial cross-contamination from surfaces to food can contribute to foodborne disease. The cross-contamination rate of Enterobacter aerogenes on household surfaces was evaluated by using scenarios that differed by surface type, food type, contact time (<1, 5, 30, and 300 s), and inoculum matrix (tryptic soy broth or peptone buffer). The surfaces used were stainless steel, tile, wood, and carpet. The food types were watermelon, bread, bread with butter, and gummy candy. Surfaces (25 cm2) were spot inoculated with 1 ml of inoculum and allowed to dry for 5 h, yielding an approximate concentration of 107 CFU/surface. Foods (with a 16-cm2contact area) were dropped onto the surfaces from a height of 12.5 cm and left to rest as appropriate. Posttransfer, surfaces and foods were placed in sterile filter bags and homogenized or massaged, diluted, and plated on tryptic soy agar. The transfer rate was quantified as the log percent transfer from the surface to the food. Contact time, food, and surface type all had highly significant effects (P < 0.000001) on the log percent transfer of bacteria. The inoculum matrix (tryptic soy broth or peptone buffer) also had a significant effect on transfer (P = 0.013), and most interaction terms were significant. More bacteria transferred to watermelon (∼0.2 to 97%) than to any other food, while the least bacteria transferred to gummy candy (∼0.1 to 62%). Transfer of bacteria to bread (∼0.02 to 94%) was similar to transfer of bacteria to bread with butter (∼0.02 to 82%), and these transfer rates under a given set of conditions were more variable than with watermelon and gummy candy.

IMPORTANCE The popular notion of the “five-second rule” is that food dropped on the floor and left there for <5 s is “safe” because bacteria need time to transfer. The rule has been explored by a single study in the published literature and on at least two television shows. Results from two academic laboratories have been shared through press releases but remain unpublished. We explored this topic by using four different surfaces (stainless steel, ceramic tile, wood, and carpet), four different foods (watermelon, bread, bread with butter, and gummy candy), four different contact times (<1, 5, 30, and 300 s), and two bacterial preparation methods. Although we found that longer contact times result in more transfer, we also found that other factors, including the nature of the food and the surface, are of equal or greater importance. Some transfer takes place “instantaneously,” at times of <1 s, disproving the five-second rule.

Schaffner does science: ‘Five second rule’ for food on floor is untrue, study finds

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Friend of the barfblog.com Don Schaffner of Rutgers is having his pop-science moment in the sun.

schaffner-facebook-apr-14And he did it right.

Press release before peer-review, whatever faults peer-review has, is a bad idea.

(My previous lab had our moment in 2004 when we trashed food safety practices on TV cooking shows; it was peer-reviewed before we talked about it.)

So Schaffner and graduate student Robyn Miranda, waited until their results were published, and then destroyed the 5-second rule: you know, food is safe if it’s on the floor for less than 5-seconds.

Christopher Melesept of the N.Y. Times reports a new study debunks the so-called five-second rule.

Professor Donald W. Schaffner, a food microbiologist at Rutgers University in New Jersey, said a two-year study he led concluded that no matter how fast you pick up food that falls on the floor, you will pick up bacteria with it.

The findings in the report — “Is the five-second rule real?” — appeared online this month in the American Society for Microbiology’s journal,Applied and Environmental Microbiology.

Researchers at Aston University’s School of Life and Health Sciences in England reported in 2014 that food picked up a few seconds after being dropped is “less likely to contain bacteria than if it is left for longer periods of time,” giving rise to news accounts suggesting that eating the food might be harmless. Those findings, and research done at the University of Illinois in 2003, did not appear in a peer-reviewed journal, Professor Schaffner noted.

Even though the five-second rule is a bit of folklore, it still raised important public health issues that demanded closer scrutiny, he said. He cited research by the Centers for Disease Control, which found that surface cross-contamination was the sixth most common contributing factor out of 32 in outbreaks of food-borne illnesses.

5-second-ruleProfessor Schaffner and a master’s thesis student, Robyn C. Miranda, tested four surfaces — stainless steel, ceramic tile, wood and carpet — and four different foods: cut watermelon, bread, buttered bread and strawberry gummy candy. They were dropped from a height of five inches onto surfaces treated with a bacterium with characteristics similar to salmonella.

The researchers tested four contact times — less than one second and five, 30 and 300 seconds. A total of 128 possible combinations of surface, food and seconds were replicated 20 times each, yielding 2,560 measurements.

The research found that the five-second rule has some validity in that longer contact times resulted in transfer of more bacteria. But no fallen food escaped contamination completely. “Bacteria can contaminate instantaneously,” Professor Schaffner said in a news release.

Carpet had a very low rate of transmission of bacteria compared with tile and stainless steel; transfer rates from wood varied.

The composition of the food and the surface on which it falls matter as much if not more than the length of time it remains on the floor, the study found. Watermelon, with its moisture, drew the highest rate of contamination and the gummy candy the least.

In an interview, Professor Schaffner said, “I will tell you on the record that I’ve eaten food off the floor.” He quickly added: “If I were to drop a piece of watermelon on my relatively clean kitchen floor, I’m telling you, man, it’s going in the compost.”

The history of the five-second rule is difficult to trace but it is attributed apocryphally to Genghis Khan, who declared that food could be on the ground for five hours and still be safe to eat, Professor Schaffner said.

William K. Hallman, an experimental psychologist and a professor at the Department of Human Ecology at Rutgers University, said people do not put every decision through a risk-benefit filter and instead rely on cognitive shortcuts called heuristics to help in their daily lives.

“It’s a way of making a very quick decision with whatever data is available,” he said in an interview.

But sometimes those shortcuts can be based on flawed assumptions or missing information.

For instance, germs are invisible and so they are easy to ignore when “something of particular value, like a yellow peanut M&M” falls to the floor, he said. Because germs are out of sight, the belief is there is no harm in picking up the M&M and popping it in your mouth.

celebrity-chefsDouglas Powell, a former professor of food safety and the publisher of barfblog.com about food safety, added that people eat from the floor because they are told not to waste food.

People are also impervious to risk. “I’ve done this all my life and never gotten sick; I did this a couple of days ago and nothing happened,” he said in an email.

Or as Professor Schaffner observed: “The first kid, the pacifier falls on the floor, oh my God, we have to sterilize it. By the third kid, it’s like ‘whatever.’ ”

Research has shown that people think germs belong to other people, Professor Hallman said. For instance, people generally believe their bathrooms are cleaner than a public restroom. In fact, that is not the case because public restrooms are cleaned more regularly, he said in an interview.

People also misunderstand the transmission of germs.

“We sort of joke about the five-second rule, but people act as if germs take some period of time to race to the item that fell on the floor,” he said.

People also do not recognize the symptoms of food-borne illnesses and tend to blame them on the last thing they ate, so they do not connect how their earlier actions might have made them sick.

food-safety-asshole-schaffnerAre men more likely to eat off the floor than women?

Yes, according to Professor Hallman. In contrast to women, men say they more frequently engage in behaviors such as picking up food or a fork that has fallen to the floor, or picking an insect or a hair out of their food then continuing to eat, he said. The findings came from a phone survey of 1,000 Americans in 2005.

Anthony Hilton, a professor of microbiology at Aston University, said a survey of nearly 500 people found 81 percent of women said they followed the rule — they would not eat anything that lingered on the floor — compared with 64 percent of men, the magazine “Scientific American” reported.

“Hilton says he doesn’t have a good explanation for this gender differentiation but points out that this finding is consistent with other research into the five-second rule,” the magazine wrote. “One possible conclusion: This is tacit confirmation of another piece of folk wisdom — men are less discerning when it comes to their food’s cleanliness.”

 

Five-second food safety BS; PR (peer review) before PR (press release)

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Friend of the blog, Don Schaffner (left, sort of as shown), a professor of food safety at Rutgers University and co-host of Food Safety Talk writes:

I can tell when something is a big news story.

First, I read about it in my news feed from one or more sources. Second, friends and family send it to me. By these two criteria, the recent news about the five second rule qualifies as a big news story. No links to any of the news outlets blathering on about this, except for the Beacon Journal, 5.second.rulewho contacted our colleague Jeff LeJeune to comment on the story. Props to them for at least checking with a reputable expert (shurley some mistake, he’s Canadian).

barfblog.com readers are probably aware of this story. And it’s a story, or a press release, not a study.

The press release is apparently based on a PowerPoint presentation. The study has not undergone any sort of peer review, as far as I know. Science by press release is something that really bugs me. It’s damned hard to do research. It’s even harder to get that research published in the peer-reviewed literature. And when reputable news outlets publish university press releases without even editing them, that does a disservice to everyone; the readers, the news outlet, and even the university researchers.

I do have to give credit to the Ashton University press officer, who responded promptly to my request for more information when I clicked on the link on the website where the press release was posted. And it certainly is better to have a PDF of a PowerPoint presentation, instead of just a press release. But it’s still not a peer-reviewed manuscript.

A review of the slide set shows a number of problems with the study. The researchers present their data as per cent transfer. As my lab has shown repeatedly, through our own peer-reviewed research, when you study cross-contamination and present the results as percentage transfer, those data are not normally distributed. A logarithmic transformation appears to be suitable for converting percentage transfer data to a normal distribution. This is important because any statistics you do on the results generally assume the data to be normally distributed. If you don’t verify this assumption first, you may conclude things that aren’t true.

The next problem with the study is that the authors appear to have only performed three replicates for most of the conditions studied. Again, as my own peer-reviewed research has shown, the nature of cross-contamination is such that the data are highly variable. In our experience you need 20 to 30 replicates to reasonably truly characterize the variability in logarithmically transformed percent transfer data.

Our research has also shown that the most significant variable influencing cross-contamination appears to be moisture. This is not surprising. Bacteria need moisture to move from one location to another. When conditions are dry, it’s much less likely that a cell will be transferred.

Another problem that peer-reviewers generally pick up, is an awareness (or lack thereof) of knowledge of the pre-existing literature. Research on the five-second rule is not new. I’m aware of at least three groups that schaffnerhave worked in this area.  Although it’s not peer-reviewed, the television show MythBusters has considered this issue. Paul Dawson at Clemson has also done research on the five-second rule. Dawson’s research has been peer-reviewed and was published in the Journal of Applied Microbiology. Hans Blaschek and colleagues were, as far as I know, the first lab to ever study this. Although this research was never published, it did win an Ig Noble prize.

If you don’t have any pathogens on your kitchen floor, it doesn’t matter how long food sits there. If you do have pathogens on your kitchen floor, you get more of them on wet food than dry food. But in my considered opinion, the five-second rule is nonsense. I’m a scientist, I’ll keep an open mind. I know what some people in my lab will be working on this summer. And I’ll tell you more about it…  after it’s been accepted for publication in a peer-reviewed journal.

5-second rule should be 0-second rule

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A couple of my Canadian kids were visiting last week during their university spring break. They’re both in biology, so the fruit don’t fall far from the … nevermind.

We were at Target – always a popular outing because Target stores are only now becoming established in Canada – and got some M&M’s for Sorenne. She dropped one on the floor and then picked it up and ate it.

I shrugged.

This was terrible food safety behavior on my part but I can’t babysit all the time.

And from my perspective, the risk was low.

The N.Y. Times quotes Dr. Roy M. Gulick, chief of the division of infectious diseases at Weill Cornell Medical College, as saying,

“The five-second rule probably should become the zero-second rule. Eating dropped food poses a risk for ingestion of bacteria and subsequent gastrointestinal disease, and the time the food sits on the floor does not change the risk.”

In general, if there are bacteria on the floor, they will cling to the food nearly immediately on contact, Dr. Gulick said. Factors that influence the risk and the rate of bacterial transfer include the type of floor; the type of food; the type of bacteria; and how long the bacteria have been on the floor.

In a study published in 2006 in The Journal of Applied Microbiology, Clemson University researchers tested salmonella placed on wood, tile or carpet, and dropped bologna on the surfaces for 5, 30 or 60 seconds. With both wood and tile, more than 99 percent of the bacteria were transferred nearly immediately, and there was no difference by the time of contact. Carpet transferred a smaller number of bacteria, again with no difference by contact time. The amount transferred decreased over hours, but there were still thousands of the bacteria per square centimeter on the surfaces after 24 hours, and hundreds survived on the surfaces for as long as four weeks. As few as 10 salmonella bacteria can cause gastroenteritis.