Food Safety Talk 137: Grandma makes the best pickles

Don and Ben talk High Sierra and bricking a MacBook Air, Gord Downie of the Tragically Hip, State Fair judging, pH test strips, mail order food safety and cold brewed canned coffee. They also do some listener feedback on food safe issues related to brewing beer.

Episode 137 can be found here and on iTunes.

Show notes so you can follow along at home:

Food Safety Talk 135: This is a podcast

Don and Ben are on the road, talking to some of the best folks in the food safety world at the NEHA Region 4 conference/FDA Central Region retail food protection seminar in Minneapolis. This recording was an experiment, the first Food Safety Talk recorded in front of a live, non-studio audience. Topics included raw milk, hepatitis A, listener feedback on liquid nitrogen, our favorite Bond movies and least favorite pathogens.

Episode 135 can be found here and on iTunes.


Show notes so you can follow along at home:

Microbiological failure? UK school forces teachers to shake hands with pupils to help kids feel respected

Trevor Noah of The Daily Show rarely shakes hands with guests or correspondants.

He’s big into the fist-bump.

Maybe Schaffner can design a study to figure out which is microbiologically safer.

It’d be another pop-culture hit.

Maybe someone has done it.

Whatever, the  handshaking policy introduced by a new principal has led to panic among staff and parents.

Some teachers at Tunbridge Wells Grammar School for Boys, southeast of London, are now arming themselves with hand sanitiser amid fears that shaking hands up to 150 times a day may cause them to pick up germs.

Principal Amanda Simpson is standing by her decision, which sees teachers shaking hands with every member of their class before each lesson.

One parent told local news website Kent Live that she was worried about the consequences of the mandatory handshaking.

“It will be interesting to see what happens if there’s an outbreak of Norovirus,” she said.

“I assume it was introduced because the new head wanted to introduce some element of respect – but I wouldn’t think that sort of thing would make any difference.”

Ms Simpson believes that starting every lesson “with a handshake and a smile” makes children feel welcome and appreciated.

She confirmed that hand sanitiser was available throughout the school for anyone worried about the spread of germs.

Shigella in Kansas: Proper handwashing requires proper tools

There was this one time, when I was in Kansas, and there was an outbreak of something at the local high school.

Stalker alert: I went to the boys’ bathroom.

No paper towel. No soap.

Proper handwashing requires access to proper tools.

The Shawnee County Health Department and KDHE are checking several shigellosis cases in children.

USD 501 confirms it centers on Highland Park Central Elementary, saying the district sent information to those parents.

Shigellosis is a gastro intestinal illness caused by a bacteria.

It is treatable and most people quickly recover from symptoms including diarrhea, fever, nausea, vomiting, and stomach cramps.

Shigella is found in the feces of an infected person. It’s spread by close contact, and by eating and drinking contaminated food or water.

To stop the spread, always wash your hands thoroughly with soap and water before eating. Do not share food, drinks, spoons and or straws.

No paper towel. No soap.

Proper handwashing requires access to proper tools.

Those are the kinds of questions that get full professors fired.

Lots of Texas is under water; flooding is devastating

Today is our first full day of Fall, when it comes to scheduling, with both kids back in school.

I’m at home, just finished recording a podcast and have CNN on in the background. I’m watching the Hurricane Harvey coverage, in awe of the devastation of inches and inches of rain.

Last Fall, some of our close by communities in North Carolina experienced flooding following Hurricane Matthew.

I had never seen anything like it.

A couple of months later I traveled to the Greenville, North Carolina area with a few other extension folks and we shot a few videos about returning to a home after a flood. Stuff like cleaning dishes, pots and pans in Part 1; other kitchen items, including appliances, flatware and plastic, in Part 2; food for people and pets in Part 3; and refrigerators in Part 4. Amongst others.

We also have a few factsheets on disaster recovery here (including what to do with foods in refrigerators and freezers after the power has been out for a while)

Thoughts are with the people of Texas.

Just wash ’em: WaPo covers soap porn

Handwashing is making a pop culture splash this week with the New Yorker piece and today’s Washington Post article on the types of soap that serial hand washers (like a chef and recipe tester) prefer.

An owner of a restaurant group with six restaurants surely washes her hands countless times a day. Renee Erickson, a chef and cookbook author in Seattle, likes unscented soaps for a work environment. But for home, where one can have more fun, she says, “I have become a big fan of L:A Bruket’s cucumber and mint soap from Sweden”

We use whatever is on sale. Just wash ’em.

Shock and shame: Science behind getting people to wash their hands

Gimmie shelter from the ravages of time.

I’d largely forgotten about my lab’s handwashing phase, probably because I was leaving the safety (shurley not) of Kansas and heading to Australia.

But was reminded from this excerpt in The New Yorker from Nate Dern’s “Not Quite a Genius,” to be published by Simon & Schuster:

Employees must wash hands.

Employees must wash their own hands.

Employees must wash their own hands after they use the restroom.

Employees of this restaurant must wash their own hands after they use the restroom.

Employees of this restaurant must wash their own hands (literally, not metaphorically) after they use the restroom.

Employees of this restaurant must wash their own hands (literally, not metaphorically) after they use the restroom, or else they are in violation of the health code.

Employees of this restaurant must wash their own hands (literally, not metaphorically) after they use the restroom, or else they are in violation of the health code, and, no, there is no practical way to regulate or enforce this rule.

Employees of this restaurant must wash their own hands (literally, not metaphorically) after they use the restroom, or else they are in violation of the health code, and, no, there is no practical way to regulate or enforce this rule, but, yes, we still ask, and trust that you will comply.

Employees of this restaurant must wash their own hands (literally, not metaphorically) after they use the restroom, or else they are in violation of the health code, and, no, there is no practical way to regulate or enforce this rule, but, yes, we still ask, and trust that you will comply, and, O.K., we apologize for the condescending tone of the posting of this rule, which seems to imply that without such a sign we would assume that our employees are disgusting children with no regard for their own hygiene.

Employees must wash hands. Greg has been fired.

Filion, K., KuKanich, K.S., Chapman, B., Hardigree, M.K., and Powell, D.A. 2011. Observation-based evaluation of hand hygiene practices and the effects of an intervention at a public hospital cafeteria. American Journal of Infection Control 39(6): 464-470.


Hand hygiene is important before meals, especially in a hospital cafeteria where patrons may have had recent contact with infectious agents. Few interventions to improve hand hygiene have had measureable success. This study was designed to use a poster intervention to encourage hand hygiene among health care workers (HCWs) and hospital visitors (HVs) upon entry to a hospital cafeteria.


Over a 5-week period, a poster intervention with an accessible hand sanitizer unit was deployed to improve hand hygiene in a hospital cafeteria. The dependent variable observed was hand hygiene attempts. Study phases included a baseline, intervention, and follow-up phase, with each consisting of 3 randomized days of observation for 3 hours during lunch.


During the 27 hours of observation, 5,551 participants were observed, and overall hand hygiene frequency was 4.79%. Hygiene attempts occurred more frequently by HCWs than HVs (P = .0008) and females than males (P = .0281). Hygiene attempts occurred more frequently after poster introduction than baseline (P = .0050), and this improvement was because of an increase in frequency of HV hand hygiene rather than HCW hand hygiene.


The poster intervention tool with easily accessible hand sanitizer can improve overall hand hygiene performance in a US hospital cafeteria.

Wilson, S.M., Jacob, C.J. and Powell, D.A. 2011. Behavior-change interventions to improve hand hygiene practice: A review. Critical Public Health 21: 119-127.

Despite the role of hand hygiene in preventing infectious disease, compliance remains low. Education and training are often cited as essential to developing and maintaining hand-hygiene compliance, but generally have not produced sustained improvements. Consequently, this literature review was conducted to identify alternative interventions for compelling change in hand-hygiene behavior. Of those, interventions employing social pressures have demonstrated varying influence on an individual’s behavior, while interventions that focus on organizational culture have demonstrated positive results. However, recent research indicates that handwashing is a ritualized behavior mainly performed for self-protection. Therefore, interventions that provoke emotive sensations (e.g., discomfort, disgust) or use social marketing may be the most effective.

Levine writes: Investigating shoppers’ perceptions of risk

Katrina Levine, extension associate and lead author of Consumer perceptions of the safety of ready-to-eat foods in retail food store settings writes,

While I was grocery shopping one day at my regular store, I noticed that one of the doors to the dairy refrigerator case was missing. There was no sign or notice to explain the gaping hole where the door should have been in front of the shredded cheese, nor was any attempt made to compensate for the absent door, such as by relocating the items in that section or putting up a temporary covering.

After first being a bit confused when trying to reach for a non-existent handle, these questions popped into my head:

• how can the food in this section be at a safe temperature, as well as the foods on either side of it? and,

• doesn’t this missing door affect the ability of the case to maintain its temperature?

I’m a food safety nerd. Most people just want to shop and get on with whatever they are doing, but I’m subconsciously always looking for food safety behaviors. The person standing behind me was probably more interested in which brand was the least expensive or which package looked the freshest, or just wanted me to get out the way so they could buy their cheese and leave.

Does the lack of a door on a normally enclosed refrigerator case pose a food safety risk for dairy the products in that case? Depends on whom you ask. The average consumer (interpret this as you choose) often doesn’t see the same food safety risks when shopping in grocery stores compared to food safety folks.

Our group from North Carolina State teamed up with John Luchansky and Anna Porto-Fett at the U.S. Department of Agriculture’s Agricultural Research Service to investigate this difference between consumers and food safety folks in food safety risk perception when shopping at grocery stores.  We conducted a national survey and several focus groups where, instead of just describing a situation, we showed pictures of a food safety situation someone could actually encounter while shopping. In addition to asking questions about whether each photo was safe or unsafe, we wanted to know about the actions, if any, people would take to do something about a situation they thought was unsafe. We prodded them further with questions about how their perceptions of safety would affect their shopping behaviors.

We found that consumers and food safety folks don’t always see the same food safety risks. There were some situations consumers perceived as risky but that weren’t actually risks, like seeing an insect on the floor. There were also some risks that food safety folks saw but consumers missed, like food not properly stored within the refrigerated area.

I was explaining our study to a friend the other day, and she flat out told me, “I look for food quality when I’m shopping – is it fresh, is there mold or signs of damage, does it look ok?” This is exactly what we found. Consumers are looking for those quality aspects, but aren’t always seeing the warning signs that the safety of the food could be at risk. The viruses, bacteria, and other things that cause foodborne illness such as Listeria monocytogenes, might be present on foods in the grocery store at high levels by not storing soft cheeses at the proper temperature, allowing bacteria to grow more quickly.

Our research team will be taking this one step further to better understand the mind of the shopper and see things through their eyes. Everyday consumers will become our secret shoppers, and we plan to arm them with the information they need to be food safety detectives every time they shop. #citizenscience for the win.

Consumer perceptions of the safety of ready-to-eat foods in retail food store settings

Katrina Levine, Mary Yavelak, John B. Luchansky, Anna C. S. Porto-Fett, and Benjamin Chapman

Journal of Food Protection

August 2017, Vol. 80, No. 8, pp. 1364-1377



To better understand how consumers perceive food safety risks in retail food store settings, a survey was administered to 1,041 nationally representative participants who evaluated possible food safety risks depicted in selected photographs and self-reported their perceptions, attitudes, and behaviors. Participants were shown 12 photographs taken at retail stores portraying either commonly perceived or actual food safety contributing factors, such as cross-contamination, product and equipment temperatures, worker hygiene, and/or store sanitation practices. Participants were then asked to specifically identify what they saw, comment as to whether what they saw was safe or unsafe, and articulate what actions they would take in response to these situations. In addition to the survey, focus groups were employed to supplement survey findings with qualitative data. Survey respondents identified risk factors for six of nine actual contributing factor photographs >50% of the time: poor produce storage sanitation (86%, n = 899), cross-contamination during meat slicing (72%, n = 750), bare-hand contact of ready-to-eat food in the deli area (67%, n = 698), separation of raw and ready-to-eat food in the seafood case (63%, n = 660), cross-contamination from serving utensils in the deli case (62%, n = 644), and incorrect product storage temperature (51%, n = 528). On a scale of 1 to 5, where 1 was very unsafe and 5 was very safe, a significant difference was found between average risk perception scores for photographs of actual contributing factors (score of ca. 2.5) and scores for photographs of perceived contributing factors (score of ca. 2.0). Themes from the focus groups supported the results of the survey and provided additional insight into consumer food safety risk perceptions. The results of this study inform communication interventions for consumers and retail food safety professionals aimed at improving hazard identification.

Good science is fucking hard: Handwashing sensation finds cool water as effective as hot water for removing germs

I didn’t know Don Schaffner, food safety guru and pop sensation at Rutgers University, was a Brittney Spears fan.

But he writes, whoops, I did it again, putting publication of peer-reviewed research ahead of press release.

We had an article published in the Journal Food of Protection earlier this week. While this current research is no five second rule, I thought it might garner some press interest, so I worked with colleagues at my university to put together a press release. I do enjoy talking to the media as part of my job, and it’s especially fun when it’s my own research.

(That’s why I became a professor, because I was bored talking about other people’s research and wanted to talk about my own — dp)

I thought I would take a little bit of time and share with readers about the process, because you folks are into this too.

An early draft of the press release had the title “Cool Water as Effective as Hot for Killing Germs”. This led to a conversation with my colleague in media relations who explained that using the word “killing” in the headline would lead to many more hits on Google (the modern-day equivalent of “if it bleeds, it leads”). I had to explain, that while I know all about search engine optimization (SEO), I could not in good conscience tell a scientific fib. Handwashing, for the most part does not kill germs, it simply removes them from your hands, and allows them to be washed down the drain.

Which brings me to antibacterial soaps – which seem to kill germs. This particular research article did look at the question of antibacterial soaps, and basically led to the same conclusion as our other on the issue: antibacterial soaps do work better than plain soaps when it comes to reducing bacterial counts on the hands, probably because there is some actual bacterial killing going on. For a variety of reasons, antibacterial soaps tend to work people up into a lather (pun intended… who says scientists have to be serious?). I had one journalist tell me [no link for you, sleazy British Tabloid] that they had already come to the conclusion that antibacterial soaps don’t work, and could I just say that. No, I explained I could not just say that, because that’s not what our research found. Instead, we found a highly significant difference (p= 0.0003) between hand washes with an antibacterial soap, and with a similarly formulated plain soap.  In this particular study the difference was small, about 0.3 log. I know many readers of this blog are comfortable and thinking on the log scale,  but for you non-microbiologists, 0.3 log corresponds to about a 50% greater reduction. Now 50% sounds like a lot to a non-microbiologist, but when you’re doing food microbiology, sometimes the data themselves can vary by 0.5 logs, or almost 70%.  So what we ended up saying in the manuscript was,  while highly significant, the difference was “within the range of error for microbiological data (i.e., a clinically insignificant difference).” I wish I’d said that a bit more forcefully in the manuscript, but sometimes we have to make compromises in peer review. The bottom line? I believe that antibacterial soap works better than plain soap in reducing bacteria on your hands. We reach this conclusion in our meta-analysis on the subject, and even this relatively small difference can have a profound effect on public health, at least if you believe our risk assessment manuscript on the subject.

I wanted to stress in the press release, and what I’ve been leading with during my media interviews, is that wash water temperature makes no difference, at least in the range that we studied (~ 60°F to 100°F). Our data show that there was no significant difference, no matter what temperature was used in the hand wash. Water temperature has along an interesting history in the FDA model food code. It used to be that the code specified a specific water temperature for washing the hands. It turns out that that temperature was based on the temperature at which bacon grease liquefies. The current code says that hands must be washed in warm water. Elsewhere in the current code it specifies that a hand wash sink must be capable of dispensing water at 100°F,  hence our reason for doing the research.  One point that I’ve been stressing in the media interviews is that it’s all about comfort. We want people to be comfortable when their washing their hands, and so my advice is use whatever water is most comfortable for you. It remains to be seen whether we will be able to change what’s in the code. Check back in 2018 after the next Conference for Food Protection

We looked at several other factors in this research as well. We investigated the volume of soap used: 0.5 mL, one mL and two mL, and we found no difference between these volumes of soap. Of course this doesn’t mean you can use as little soap as you want, my recommendation is to use at least 0.5 mL. Using more than this doesn’t seem to make a difference. This is also consistent with what we found in our [meta-analysis](

In a recent paper published in Food Protection Trends, my PhD student Dane Jensen (who was also the lead author on this handwashing study), and I published an analysis of recommendations on handwashing signs.  Dane had a hand (pun intended, see above) in several of the handwashing research manuscripts coming out of my lab in recent years. What we found in the FPT handwashing signage research was that handwashing recommendations were all over the place. So we decided to study lather time in this current manuscript. For purposes of our research we defined lather time as the time from when the soap is applied, until the water rinse begins.  We studied five, 10, 20, and 40 second lather times.  We only saw a statistically significant difference between lather times of five and 20 seconds.  The recommendation I would draw from this finding, is to lather for at least 10 seconds.  Lathering for more than 10 seconds does not appear to offer any additional benefit.

 One of the questions that seems to come up again and again in media interviews on this topic is “who funded the research”. While I understand the motivation for the question, it’s starting to get under my skin (okay okay, I’ll stop with the puns). The question seems to imply that somehow if I take money from the industry, my results are not to be trusted. I strongly resent the implication. It’s damn difficult to get grants these days, and I don’t think it’s going to get any easier until something  changes in Washington. We funded this research using discretionary money, but I’m proud that we did it in collaboration with our co-authors from GOJO.  They were instrumental in helping us think about our experimental design, plus they gave us free soap. They are also really smart and hard-working scientists, who really sweat the details.

Is this the last word on handwashing? I doubt it. We’ve got at least one more paper from Dane’s dissertation in the pipeline, and I’ve still got more ideas. If anyone reading this believes that industry funded research is somehow tainted, and you’ve got $250,000, please get in touch.

That’s the background and shows just how much good scientists sweat the details, whereas any hack can make a claim, spread it on the Internet, supported by no data, just interpretation.

I’ve got a modest 70 peer-reviewed papers, book chapters and a book, but when I had a big lab with the money flowing, I got bored. That’s just me.

Surprisingly I still get cited in peer-reviewed journals a few times a week, so I know I’ve got a body of work that people go to.

Thee scandals of pay-for-publication journals are a smear on the scientific community, but until someone comes up with a better system, peer-review largely works.

I’ve kept my mouth shut for years while papers got written, reviewed and published.

No PR before publication.

Those who do are attention-seeking assholes and another smear on the profession.

Here’s an edited version of the Rutgers PR.

Washing our hands can keep us from spreading germs and getting sick. But a new Rutgers-New Brunswick study found that cool water removes the same amount of harmful bacteria as hot.

“People need to feel comfortable when they are washing their hands but as far as effectiveness, this study shows us that the temperature of the water used didn’t matter,” said Donald Schaffner, distinguished professor and extension specialist in food science.

In the Rutgers study, published in the June issue of the Journal of Food Protection, high levels of a harmless bacteria were put on the hands of 21 participants multiple times over a six-month period before they were asked to wash their hands in 60-degree, 79-degree or 100-degree water temperatures using 0.5 ml, 1 ml or 2 ml volumes of soap.

“This study may have significant implications towards water energy, since using cold water saves more energy than warm or hot water,” said Schaffner. “Also we learned even washing for 10 seconds significantly removed bacteria from the hands.”

While the study indicates that there is no difference between the amount of soap used, more work needs to be done to understand exactly how much and what type of soap is needed to remove harmful microbes from hands, said co-author Jim Arbogast, vice president of Hygiene Sciences and Public Health Advancements for GOJO. “This is important because the biggest public health need is to increase handwashing or hand sanitizing by foodservice workers and the public before eating, preparing food and after using the restroom,” Arbogast said.

These findings are significant, particularly to the restaurant and food industry, because the U.S. Food and Drug Administration issues guidelines, every four years, to states. Those guidelines currently recommend that plumbing systems at food establishments and restaurants deliver water at 100 degrees Fahrenheit for handwashing.

Schaffner said the issue of water temperature has been debated for a number of years without enough science to back-up any recommendation to change the policy guidelines or provide proof that water temperature makes a difference in hand hygiene. Many states, in fact, interpret the FDA guidelines as a requirement that water temperature for handwashing must be 100 degrees, he said.

The FDA is scheduled to hold a conference in 2018 to discuss the existing code and any modifications that should be made and Schaffner would like to see the water temperature policy revised at that time.

“I think this study indicates that there should be a policy change,” said Schaffner. “Instead of having a temperature requirement, the policy should only say that comfortable or warm water needs to be delivered. We are wasting energy to heat water to a level that is not necessary.”

Maybe, don’t know: Do hand sanitizers cut down on illness?

My first reaction to any food safety claim, policy or recommendation is, are fewer people going to barf?

Which greeting is the cleanest?

I usually don’t get an answer.

Because it’s really hard to associate policy with rates of barfing.

A couple of weeks ago, Karen Weintraub of The New York Times wrote: With the recent increase in use of sanitizers (hand lotions, wipes for supermarket carts, etc.) has there been any real impact on transmission of colds, flu or other diseases?

The short answer is no one knows, because no one has studied whether hand sanitizers have cut down on the number of infectious diseases among the public at large.

On a personal level, good hand hygiene clearly can make a difference in health. A 2008 study in The American Journal of Public Health concluded that improvements in hand hygiene, regardless of how the participants cleaned their hands, cut gastrointestinal diseases by 31 percent, and respiratory infections by 21 percent.

The key to stopping disease is breaking the chain that allows pathogens to be transmitted from person to person. Either hand washing or sanitizing can do that.

Sally Bloomfield, an expert in hand hygiene and an honorary professor at the London School of Hygiene and Tropical Medicine, said she always carries hand sanitizer with her when she travels. “London airport bathrooms are usually fine because they are well designed to make sure we wash our hands properly — and dry them properly,” she said, but some train “loos” leave something to be desired.

Grocery carts can be particularly risky points of transmission. Someone grabbing chicken or meat can leak the juices onto a cart and their hands, and then continue to push the cart around, transmitting pathogens like Salmonella and E. coli onto the handle. The next person who handles the cart, or the next child who sits in the top of the wagon, can then pick up the bugs.

“If you can wipe down the handle bars on the shopping cart with an alcohol-containing preparation, that’s probably a good idea,” said Dr. Cody Meissner, chief of the division of pediatric infectious disease at Floating Hospital for Children at Tufts Medical Center in Boston.

That said, Dr. Meissner and others cautioned against germaphobia. Every surface around us is coated in bacteria and other microbes, the vast majority of which are neutral or beneficial, said Liz Scott, chairwoman of the department of public health at Simmons College in Boston.

“We really need to target our hygiene practices,” she said, focusing on likely chains of transmission. That means washing your hands when you get back from the grocery store, public transit or any other public place, said Dr. Scott, who also admits to avoiding handshakes whenever possible, especially during flu season.

Fist bump.

(The pic, above left, is from a TV commercial Dettol shot at Sorenne’s school – she’s one of the blurred out kids, second row, far right).