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 barfblog.com 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](https://www.ncbi.nlm.nih.gov/pubmed/22054188).

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).

Bathrooms and barf from around the world — in Instagram

Long before Instagram and YouTube, the barfblog crew — I can’t believe I just wrote that, I never called my lab members the crew but I did call them the kids, even if I was the immature one — we were making food safety videos and taking pictures.

Just didn’t know what to do with them.

We had an entire website devoted to handwashing signs in bathrooms — as you do.

And then when I moved to Kansas in early 2006, it sorta got lost.

Someone in the lab was taking care of it and I was posting pictures of bathrooms from our trip to France, as we sat on the coast of Marseilles, but then the University of Guelph decided the sandbox wasn’t big enough for both of us so kicked me out.

Bullies.

Then the website disappeared.

Or maybe it exists somewhere.

I know my limitations, and computer technology is one of them. Which is why I’ve been using a Mac since 1987.

Now there’s thing called Instagram, which may not be as cool as Snapchat, but whatever, I like pictures.

So Chapman created a barfblogben Instagram account, and I created a barfblogdoug account, because someone already has barfblog and it’s probably me (but linked to a previous e-mail).

I did one post — Amy did it and I immediately forgot how to do it — so I’ll put this picture in here, and maybe some time she’ll show me how to do it again.

This is from the University of Queensland bathroom in the Institute for Teaching and Learning Innovation building/centre/whatever it’s called.

(All those people who used to work with me, if you know where that website it, send me a note).

KState changes handwashing recommendations

Twelve years after Chapman and I set out for Prince George, B.C., where Chapman announced his fears of both bears and jello-swim nights at the local college, and then went to Kansas State University, where I met a girl (who’s still my best friend and wife), where I got sexually advanced upon in an unpleasant manner by a professor dude, where I had lunch with the president, got a job offer, and enjoyed a great career, my former boss sent me this:

KState has changed its handwashing recommendations.

They disconnected the blow dryers in those groovy all-in-one handwashing units.

One reason I was offered the job is because I took the prez to the bathroom and showed him how shitty their handwashing recommendations were.

But that story is old.

No one should be recreating their past glory days (and if I ever quote a Bruce Springsteen song again, put me out of my misery).

Change does sometimes happen: usually not as fast as any of us would like.

Duty calls: Tweet when you barf (maybe FSA should tell Heston)

This is what is infuriating about food safety government types: they have the budgets, they have the knowledge, but they don’t have the wherewithal to confront an issue on a public scale.

heston-blumenthalThey can say, oooohhh, we use social media to track when people are barfing but they do no evaluation of their alleged interventions.

Telling people to wash their hands doesn’t mean people will wash their hands.

Elizabeth Cassin of BBC writes if you’re suffering with projectile vomiting and watery diarrhea, reach for your phone and post an update.

While it won’t ease your suffering, a tweet or two could help researchers track the spread of the winter vomiting bug (which the rest of the world calls Norovirus).

The UK Food Standards Agency has been using social media to track levels of norovirus, a highly contagious illness which spreads via food and through person-to-person contact. The symptoms usually last for one to two days, with the person remaining infectious for a further two days.

If you’ve ever had, it you know what it means: vomiting, diarrhea, pain, and the general feeling of having been run over by a car.

In 2013, the Foods Standards Agency started looking at new ways to track the virus. They analysed Google searches but found that social media was a better source of data. “It’s more about the immediacy… what’s happening in their lives right now,” says Dr Sian Thomas.

On the other hand, “if you’re in hospital or a nursing home and you’re sick, then they might take a sample and send it to a laboratory for analysis,” she says.

The FSA compared this official sample data with the volume of relevant tweets and concluded that “there’s a really good correlation between the number of mentions on Twitter of ‘sick’ and a range of search terms, with the incidents of illness as defined by laboratory reports.”

“Our current estimate is that between 70-80% of the time, we are able to accurately predict an increase the next week.”

If the team predict a national outbreak, they plan to run a digital campaign explaining how to look after yourself.

“The intervention is really quite basic,” she notes. “It’s about washing your hands, it’s about looking after yourself, and not coming in to contact with other people while you’re sick.”

Norovirus can be dangerous for children or the elderly. Fortunately for healthy adults though, the illness is usually a minor, if messy, inconvenience.

 

From the duh files: Study suggests handwashing compliance in child care facilities insufficient

Except the authors get it wrong.

This is the most telling quote from the PR, and I’m not sure who reviewed this shit:

handwashing-loads“The guidelines outline sequential handwashing steps that need to be followed, including use of warm water, soap, paper towels, and continuing for 20 seconds. This study confirms the results of previous studies in this area that there is a need for funding of education and training about proper hand hygiene.”

Water temp doesn’t matter. 20 seconds doesn’t matter. And give us more money to ingratiate ourselves with future funders.

Anyone who has worked in a daycare or restaurant, for lousy pay, knows that time constraints and screaming babies sometimes interfere with best practice. Did anyone follow the guidelines? Acknowledge the realities of the world we’re in, and offer practical advice. But you’ll probably get funded in the next round.

Child care personnel properly clean their hands less than a quarter of the times they are supposed to, according to a study published in the December issue of the American Journal of Infection Control, the official journal of the Association for Professionals in Infection Control and Epidemiology (APIC, http://www.apic.org).

A new study from the University of Arkansas used video cameras to record handwashing habits and compliance among child care workers at an early childhood center in northwest Arkansas. The researchers found that personnel and parents at the facility on average followed proper handwashing procedures only 22 percent of the time before and/or after tasks such as wiping noses, emptying garbage cans, preparing food, changing diapers, or using their cell phones. Caregivers washed 30 percent of the time it was called for, with paraprofessional aides at 11 percent, and parents at 4 percent.

“Handwashing is an important component of reducing illness transmission among children in early childhood centers, especially for the adults in charge of their care,” said lead study author Jennifer Henk, PhD. “As we seek to improve overall quality in early childhood settings, our study shows the need to adopt creative strategies to increase handwashing compliance and efficacy.”

amy-sorenne-handwashingSurveillance cameras were used to randomly record 25 hours of handwashing compliance in ten different classrooms. The center was aware of the cameras, but not alerted to the primary purpose of the study. There were a total of 349 handwashing opportunities in the 25 hours; 78 corresponding handwashing events took place for an overall compliance rate of 22 percent. Handwashing opportunities and events were based on guidelines for early child care established by the American Academy of Pediatrics. The guidelines outline sequential handwashing steps that need to be followed, including use of warm water, soap, paper towels, and continuing for 20 seconds. This study confirms the results of previous studies in this area that there is a need for funding of education and training about proper hand hygiene.

“Hand hygiene in early childhood centers is especially important because children under five years of age have only partially developed immune systems, increasing their susceptibility to communicable diseases,” said Susan Dolan, RN, MS, CIC, FAPIC, president of APIC. “Studies have shown that children who spend time in an early childhood care center are two to three times more likely to acquire infections than children cared for in the home, with respiratory and gastrointestinal infections posing the highest risks.”

Handwashing can prevent about 30 percent of diarrhea-related sicknesses and about 20 percent of respiratory infection in children, according to the Centers for Disease Control and Prevention.

So what are the creative strategies to increase handwashing compliance? Waste of time.

DC bartender and artist Chantal Tseng makes poop murals in bathrooms

According to bizjournals.com the murals are about poop. Not made out of poop (sadly).screen-shot-2016-10-19-at-5-20-30-pm

Regular Washington imbibers may notice something if they take an extra minute in the restrooms at the new REI flagship store in NoMa: the name of one of D.C.’s favorite bartenders, Chantal Tseng, inscribed on a roll of toilet paper held by a cartoon bear on the wall.

Washington City Paper even included her in a piece it did on D.C.’s mixologists turned chalk artists — which is how the folks at REI found her when they were looking for artists for murals at the new store.

After the call, Tseng enlisted D.C.’s go-to chalk artist, Patrick Owens, for help on the project.

screen-shot-2016-10-19-at-5-20-47-pmTseng and Owens drew extra animals in addition to the bear, and added leaves, animal tracks and, yes, piles of poop to the mural, which is titled “Poop in the Woods: Droppin’ Deuces Wild.” Tseng likes to incorporate haiku into her drawings, so she added a thematic one written backward that can only be read in the bathroom mirrors: “Last chance to soap up/ before heading back out there/ think of the children.”

Yes. Think about the children. And all the other folks who might get poop from your hands onto their hands or in their food.

Check if there’s paper towels in the kids’ bathrooms: Evidence-based interventions of Norovirus outbreaks in China

In resource-limited settings where laboratory capacity is limited and response strategy is non-specific, delayed or inappropriate intervention against outbreaks of Norovirus (NoV) are common. Here we report interventions of two norovirus outbreaks, which highlight the importance of evidence-based modeling and assessment to identify infection sources and formulate effective response strategies.

norovirus-bathroomMethods

Spatiotemporal scanning, mathematical and random walk modeling predicted the modes of transmission in the two incidents, which were supported by laboratory results and intervention outcomes.

Results

Simulation results indicated that contaminated water was 14 to 500 fold more infectious than infected individuals. Asymptomatic individuals were not effective transmitters. School closure for up to a week still could not contain the outbreak unless the duration was extended to 10 or more days. The total attack rates (TARs) for waterborne NoV outbreaks reported in China (n = 3, median = 4.37) were significantly (p < 0.05) lower than worldwide (n = 14, median = 41.34). The low TARs are likely due to the high number of the affected population.

Conclusions

We found that school closure alone could not contain Norovirus outbreaks. Overlooked personal hygiene may serve as a hotbed for infectious disease transmission. Our results reveal that evidence-based investigations can facilitate timely interventions of Norovirus transmission.

BioMed Central Public Health

Tianmu Chen, Haogao Gu, Ross Ka-Kit Leung, Ruchun Liu, Qiuping Chen, Ying Wu and Yaman Li

DOI: 10.1186/s12889-016-3716-3

https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-016-3716-3

Is there anybody out there? Physicians and handwashing

Our objectives were to evaluate the utility of electronic hand hygiene counting devices in outpatient settings and the impact of results feedback on physicians’ hand hygiene behaviors.

big-brother-1984We installed 130 electronic hand hygiene counting devices in our redesigned outpatient department. We remotely monitored physicians’ hand hygiene practices during outpatient examinations and calculated the adherence rate as follows: number of hand hygiene counts divided by the number of outpatients examined multiplied by 100. Physician individual adherence rates were also classified into 4 categories.

Results

Two hundred and eighty physicians from 28 clinical departments were monitored for 3 months. The overall hand hygiene adherence rate was 10.7% at baseline, which improved significantly after feedback to 18.2% in the third month. Of the clinical departments, 78.6% demonstrated significant improvement in hand hygiene compliance. The change in the percentage of physicians in each category before and after feedback were as follows: very low (84.3% to 72.1%), low (8.6% to 14.3%), moderate (2.9% to 8.9%), and high (4.3% to 4.6%), from the first to third month, respectively. Based on category assessment, 17.1% of physicians were classified as responders.

Conclusions

Physicians’ adherence to hand hygiene practices during outpatient examinations was successfully monitored remotely using electronic counting devices. Audit and feedback of adherence data may have a positive impact on physicians’ hand hygiene compliance.

Utility of electronic hand hygiene counting devices for measuring physicians’ handwashing

American Journal of Infection Control, DOI: http://dx.doi.org/10.1016/j.ajic.2016.08.002

A Arai, M Tanabe, A Nakamura, D Yamasaki, Y Muraki, T Kaneko, A Kadowaki, M Ito

http://www.sciencedirect.com/science/article/pii/S0196655316307532

 

Inevitability of reproduction – TV cooking show edition

In 2004, my laboratory reported (and by reported I mean published in a peer-reviewed journal) that, based on 60 hours of detailed viewing of television cooking shows, an unsafe food handling practice occurred about every four minutes, and that for every safe food handling practice observed, we observed 13 unsafe practices. The most common errors were inadequate hand washing and cross-contamination between raw and ready-to-eat foods.celebrity_chefs4

The abstract is below.

Once the paper was published, it made headlines around the globe.

And then it started getting replicated. Texas, Europe, a few other places, and now Massachusetts.

Compliance With Recommended Food Safety Practices in Television Cooking Shows

Nancy Cohen, Rita Olsen

Journal of Nutrition Education and Behavior, 2016 Aug 28. pii: S1499-4046(16)30715-1. doi: 10.1016/j.jneb.2016.08.002. [Epub ahead of print]

Objective

Examine compliance with recommended food safety practices in television cooking shows.

Methods

Using a tool based on the Massachusetts Food Establishment Inspection Report, raters examined 39 episodes from 10 television cooking shows.

Results

Chefs demonstrated conformance with good retail practices for proper use and storage of utensils in 78% of episodes; preventing contamination (62%), and fingernail care (82%). However, 50% to 88% of episodes were found to be out of compliance with other personal hygiene practices, proper use of gloves and barriers (85% to 100%), and maintaining proper time and temperature controls (93%). Over 90% failed to conform to recommendations regarding preventing contamination through wiping cloths and washing produce. In only 13% of episodes were food safety practices mentioned.

Conclusions and Implications

There appears to be little attention to food safety during most cooking shows. Celebrity and competing chefs have the opportunity to model and teach good food safety practices for millions of viewers.

 Mathiasen, L.A., Chapman, B.J., Lacroix, B.J. and Powell, D.A. 2004. Spot the mistake: Television cooking shows as a source of food safety information, Food Protection Trends 24(5): 328-334.

Consumers receive information on food preparation from a variety of sources. Numerous studies conducted over the past six years demonstrate that television is one of the primary sources for North Americans. This research reports on an examination and categorization of messages that television food and cooking programs provide to viewers about preparing food safely. During June 2002 and 2003, television food and cooking programs were recorded and reviewed, using a defined list of food safety practices based on criteria established by Food Safety Network researchers. Most surveyed programs were shown on Food Network Canada, a specialty cable channel. On average, 30 percent of the programs viewed were produced in Canada, with the remainder produced in the United States or United Kingdom. Sixty hours of content analysis revealed that the programs contained a total of 916 poor food-handling incidents. When negative food handling behaviors were compared to positive food handling behaviors, it was found that for each positive food handling behavior observed, 13 negative behaviors were observed. Common food safety errors included a lack of hand washing, cross-contamination and time-temperature violations. While television food and cooking programs are an entertainment source, there is an opportunity to improve their content so as to promote safe food handling.