This research collects and reviews existing handwashing signs and subjects them to quantitative analysis. An Internet search produced a database of handwashing signs. Lather time, rinse time, overall wash time, water temperature, water use, drying method, technique, and total number of steps were recorded.
Eighty-one unique handwashing signs were identified. Each sign had between one and thirteen steps. Thirty-seven signs indicated a specific lather time, with average time ~18 s. No sign suggested > 20 s lather, and none suggested < 10 s lather. Twenty-four signs recommended use of warm water. Two signs recommended 100°F (37.8°C) water and one recommended hot water. Sixty-two signs made a recommendation on drying hands, and fifty-three suggested using a paper towel.
Our analysis reveals that handwashing sign instructions can vary quite widely. Lack of consistent hand wash guidance on signage may contribute in part to a lack of handwashing consistency and compliance. Our study serves as a foundation for future research on handwash signage.
Quantitative analysis of recommendations made in handwashing signs
Food Protection Trends, vol. 35, no. 4, pp. 270-279, July 2015
Food Safety Talk, a bi-weekly podcast for food safety nerds, by food safety nerds. The podcast is hosted by Ben Chapman and barfblog contributor Don Schaffner, Extension Specialist in Food Science and Professor at Rutgers University. Every two weeks or so, Ben and Don get together virtually and talk for about an hour. They talk about what’s on their minds or in the news regarding food safety, and popular culture. They strive to be relevant, funny and informative — sometimes they succeed. You can download the audio recordings right from the website, or subscribe using iTunes.
This episode starts with a discussion of Ben’s taste in music, and then quickly moves into documentaries. Ben recently watched Jodorowsky’s Dune, on Don’s recommendation. This documentary has some ‘artful nudity’ that leads to a discussion of perverts on airplanes and the appropriateness of reading material such as Fifty Shades of Grey while crammed into an airplane seat. The conversation naturally transitioned into a discussion of microphone stands and coffee. Ben notes that owning a Nespresso machine has changed his life; he ranks it among his top 10 life changing things (including his wife and children). The guys then discuss other pop-culture topics including Deflate-Gate and TV shows The Affair,Portlandia (which had an episode satirizing raw milk), and Garfunkel and Oates. Note that Portlandia is required viewing before attending IAFP 2015 in Portland this summer
Ben leads off the actual food safety talk by mentioning sprouts and the number of outbreaks associated with them. The guys then discuss experiments to validate sprout cooking processes including charred bean sprouts. Ben then brings up the idea of baking cookies in a car and a visit from Linda Harris (who now downloads and listens). From there the talk turns to pathogen reduction validations for baking processes spurred by the Wegmans recall of baked fruit dessertslast summer, presumably because they contained peaches recalled for Listeria.
The FDA’s Reportable Food Registry, along with CDC whole genome sequencing of pathogens, is enabling more illnesses to be linked to products, as seen in Salmonella Braenderup linked to nut butter. Ben predicts more businesses will have to issue recalls because of validation issues, and the investigations that accompany these recalls will isolate pathogens from within facilities that can be linked to other illnesses which have occurred over months and years prior.
The discussion then turns to the very bad blizzard that New Jersey never had. Don discusses the similarities between the models for weather forecasting and models in food safety. Both situations have consequences for over or under reacting; both present risk management and risk communication difficulties.
A tweet from The New Yorker made Don mad: Bill Marler may be all that stands between you and Salmonella. This resulted in Don tweeting back to The New Yorker. Ben mentioned it was probably just Betteridge’s Law of Headlines. Bill Marler is probably not all that stands between you and Salmonella; as there are a few more people trying to do the right thing. The guys then go on to discuss how Marler and Caroline Smith DeWaal, a lawyer with the Center for Science in the Public Interest, have become controversial but generally respected food safety personalities over the years.
Pork has a reputation for being dangerous but decreases in the prevalence of Trichinella and Americans tendency to overcook pork have reduced the actual risk, so Ben wanted to discuss a recent MMWR Trichinellosis report. Don mentions ‘The Batz Report’ which determined the top 10 pathogen-food combinations with the greatest burden in public health. This led to a discussion of sample size, detection limits, consumption rates, and risk messaging, leading to the conclusion that cultural practices in food preparation adds complexity to the determination of risk.
Dr. Scott Lindquist, the Washington state epidemiologist for communicable diseases, said the move is a precaution while county, state and federal officials determine the source of the outbreak that sent at least eight people to hospitals.
“We’re recommending they not have any more events until we’ve finished our investigation,” Lindquist said.
The request immediately affects a dog show planned for Saturday by the Mount Baker Kennel Club, expected to attract 800 canines and more than 2,000 people to the Northwest Washington Fair & Event Center.
Stiles said she understood and applauded health officials’ efforts to make sure no one else got sick at the site where more than 1,300 first-graders were exposed to Shiga toxin-producing E. coli O157: H7.
The outbreak followed the annual Milk Makers Fest held April 21-23. At least 15 people contracted lab-confirmed infections, with eight hospitalized and three who developed hemolytic uremic syndrome, a life-threatening complication of E. coli illness.
About 30 others are still being tested. Whatcom County health officials originally estimated as many as 47 people were sickened, but they’ve changed the way the cases are defined.
When Michael Pollan endorses an article, I know it’s BS.
So it is with Kate Murphy’s piece in the New York Times on Sunday, that says the U.S. food supply is “arguably the safest in the world” and asks “whether our food could perhaps be too clean.”
I’ve been hearing this for 25 years. It’s a tantalizing belief but at this point that’s all it is – a belief.
Cherry-picking data to support a pre-existing theory remains a belief.
I could tell an equal number of stories about my mother who got undulate fever from raw milk as a child, or my aunt who suffered with cyclospora from basil in Florida, or Champan who spent a weekend in our toilet from Campylobacter in Kansas, but it’s not science.
There are research areas worth exploring, but we humans don’t know much about applying this germ theory, especially to the genetically susceptible.
The theory that there might be such a thing as “too clean” food stems from the hygiene hypothesis, which has been gaining traction over the last decade. It holds that our modern germaphobic ways may be making us sick by harming our microbiome, which comprises all the microscopic beasties — bacteria, viruses, fungi, mites, etc. — that live in and on our bodies.
Research so far has focused primarily on the detrimental effects of cesarean births and not breast-feeding, which may inhibit the formation of a robust microbiome, and the use of antibacterial soaps and antibiotics, which diminish the microbiome once it is established.
A result is an immune system that essentially gets bored, spoiling for a fight and apt to react to harmless substances and even attack the body’s own tissues. This could explain the increasing incidence of allergies and autoimmune disorders such as asthma, rheumatoid arthritis and inflammatory bowel syndrome.
It could also explain my latest fart.
There is also the suggestion that a diminished microbiome disrupts hormones that regulate hunger, which can cause obesity and metabolic disorders.
When it comes to foodborne illness, the idea is that fewer good bacteria in your gut means there is less competition to prevent colonization of the bad microbes, leading to more frequent and severe bouts of illness.
Moreover, your underutilized immune system may lose its ability to discriminate between friend and foe, so it may marshal its defenses inappropriately (e.g., against gluten and lactose) or not at all.
All of this is hard to prove.
That should be the headline.
Anyone who has visited a country with less than rigorous sanitation knows the locals don’t get sick from foods that can cause tourists days of toilet-bound torment.
That’s because the susceptible ones have died off.
“We have these tantalizing bits of evidence that to my mind provide pretty good support for the hygiene hypothesis, in terms of foodborne illness,” said Guy Loneragan, an epidemiologist and professor of food safety and public health at Texas Tech.
Yes, it’s tantalizing.
This is not to say we’d be better off if chicken producers eased up on the salmonella inspections, we ate recalled ice cream sandwiches and didn’t rinse our produce.
Rinsing produce ain’t going to do much either way; but may make the consumer feel cleaner.
Murphey says it is worth noting that serious foodborne diseases — the ones that make it into the news, like listeria, salmonella, E. coli, cryptosporidium and campylobacter — are mainly diseases of immuno-compromised populations.
A specific water temperature is not necessary for handwashing – it’s a matter of preference. I like to wash my hands in sorta cool water. I’ve been told that folks in Dubai like this too. Some people prefer warm water.
According to WTSP, in a behind-the-scenes at a restaurant, a Tampa food safety consultant says that hot handwashing water is necessary to kill pathogens.
“As the public you don’t have the opportunity to go behind the counter,” said former health inspector Louayy Bayyat. “We trust there is somebody inspecting for us.”
Bayyat retired from the state as a district supervisor and now runs his own restaurant food safety consulting firm. He recently took us along for a mock inspection inside a Bay area sushi restaurant to show us what really happens on an inspection.
Our first stop was the employee hand sink when Bayyat immediately reached for soap and paper towels, beginning the inspection by washing his hands.
It was at the hand washing sink where we discovered our first problem.
“We don’t use hot water,” said the owner referencing a sink next to the sushi bar.
Bayyat informed the owner hot water was required and important to kill viruses on employee hands.
Hot water (at least 100F) is required by the Food Code, for preference, but it would be pretty uncomfortable to wash your hands in water hot enough to kill bacteria and inactivate viruses. I just tested my comfort limit in my kitchen sink, and 120F is too hot for me.
Despite endless statements to just wash hands to be safe — in the kitchen, in food service, at the petting zoo — little research has been done to quantify what actually works when it comes to handwashing.
U.S. government recommendations for 15-20 seconds of handwashing under vigorously flowing water after a potential contamination event may not be practical in a food service environment.
Dr. Donald Schaffner, a professor of food safety at Rutgers University, and colleagues, have attempted to add some science to the discussion.
“Many people seem to have strongly held opinions about handwashing, says Schaffner, “but the research base for those opinions is lacking. Our research begins to dispels some popular beliefs about handwashing.”
The researchers showed that even a minimal handwash (5 seconds, no soap) can remove about 90 per cent of bacteria on hands.
Further, the research showed that towel drying was much more effective than other methods because of the friction involved in physically removing bacteria from hands.
Schaffner says “Everyone has an opinion about handwashing, but our research is beginning to provide real data to help inform sensible policy.”
Hand washing is recognized as a crucial step in preventing foodborne disease transmission by mitigating cross-contamination among hands, surfaces, and foods.
This research was undertaken to establish the importance of several keys factors (soap, soil, time, and drying method) in reducing microorganisms during hand washing. A nonpathogenic nalidixic acid–resistant Enterobacter aerogenes surrogate for Salmonella was used to assess the efficacy of using soap or no soap for 5 or 20 s on hands with or without ground beef debris and drying with paper towel or air. Each experiment consisted of 20 replicates, each from a different individual with ∼6 log CFU/ml E. aerogenes on their hands. A reduction of 1.0 ± 0.4 and 1.7 ± 0.8 log CFU of E. aerogenes was observed for a 5-s wash with no soap and a 20-s wash with soap, respectively. When there was no debris on the hands, there was no significant difference between washing with and without soap for 20 s (P > 0.05). Likewise, there was no significant difference in the reductions achieved when washing without soap, whether or not debris was on the hands (P > 0.05). A significantly greater reduction (P < 0.05) in E. aerogenes (0.5 log CFU greater reduction) was observed with soap when there was ground beef debris on the hands. The greatest difference (1.1 log CFU greater average reduction) in effectiveness occurred when ground beef debris was on the hands and a 20-s wash with water was compared with a 20-s wash with soap. Significantly greater (P < 0.05) reductions were observed with paper towel drying compared with air (0.5 log CFU greater reductions).
Used paper towels may contain high bacterial levels (>4.0 log CFU per towel) when hands are highly contaminated. Our results support future quantitative microbial risk assessments needed to effectively manage risks of foodborne illness in which food workers’ hands are a primary cause.
Quantifying the effect of hand wash duration, soap use, ground beef debris, and drying methods on the removal of Enterobacter aerogenes on hands
I have no problem with who funds research, as long as there is full disclosure and the methodology is available for critique in a peer-reviewed journal. That would be the public part.
The Daily Mail in the UK thinks readers are too dumb to ask for references, and begins with, “Paper towels are the most hygienic way to dry hands after going to the loo, a study has found.”
It took The Mirror to note that the University of Westminster’s snappily-titled study ‘Comparison of different hand-drying methods: the potential for airborne microbe dispersal and contamination‘ was published in the March 2015 edition of The Journal of Hospital Infection.
The research was commissioned by paper towel manufacturers and claims that single-use towels are the most hygienic way to dry off.
It probably is.
The research also claims that bathroom air dryers may be blasting bacteria directly into the faces of children.
However, a major hand dryer manufacturer has disputed the claims, calling the research “flawed”.
The university’s study was undertaken by leading microbiologist Keith Redway of the University’s Department of Biomedical Sciences and looked at the potential for microbial contamination from hand drying and the potential risks for the spread of microbes in the air, particularly if hands are not washed properly.
The peer-reviewed research – which was commissioned by the European Tissue Symposium (ETS) – used four different hand drying methods and three different test models to compare differences between the drying methods and their capacity to spread microbes from the hands of users potentially to other people in public washrooms.
Paper towels, a textile roller towel, a warm air dryer and a jet air dryer were compared using three different test models: acid indicator using lemon juice, yeast, and bacterial transmission from hands when washed without soap.
The University of Westminster scientists found that the jet air dryer spread liquid from users’ hands further and over a greater distance – up to 1.5 m – than the other drying methods.
They also recorded the greatest spread of microbes into the air at both near and far distances for each of the tested models.
Levels recorded at close distance for a jet air dryer revealed an average of 59.5 colonies of yeast compared with an average of just 2.2 colonies for paper towels.
At a distance of 0.2 m the jet air dryer recorded 67 colonies of yeast compared with only 6.5 for paper towels. At a distance of 1.5 m the jet air dryer recorded 11.5 colonies of yeast compared to zero for paper towels.
The research also looked at the body height at which microbes were spread by air dryers.
It found the greatest dispersal was at 0.6 – 0.9 m from the floor, the face height of small children who might be standing near the dryer when a parent is drying his or her hands.
Leading researcher Keith Redway said: “These findings clearly indicate that single-use towels spread the fewest microbes of all hand-drying methods.
“Cross contamination in public washrooms is a legitimate public health concern. The extent to which jet air dryers disperse microbes into the washroom environment is likely to have implications for policy guidance to facilities managers operating in a wide range of environments from sports venues and airports through to schools and hospitals.”
But Dyson, a major hand dryer manufacturer, strongly disputes the study’s findings.
A spokesperson said: “The paper towel industry has consistently failed to invent new technology or respond to environmental concerns.
“Paper towels are costly to buy and replace, and are rarely recycled, meaning they are sent to landfill or incinerated. To argue their case, the paper towel industry is continuing to commission research with flawed methodology.
“A study conducted by Campden BRI’s (an independent membership-based organisation carrying out research and development for the food and drinks industry worldwide) hygiene specialists found that there are no practical differences between any of the hand drying techniques investigated (paper towels, conventional air dryers and the Dyson Airblade) with regard to microbial aerosol generation.
“The very low numbers of airborne microbes resulting from use of each of the hand dryers would make an insignificant contribution to the overall background microbial loading of the air.”
A visit to a farm and the chance to see and handle animals is an exciting time for young children.
However, it is vitally important to remember that farm animals can carry harmful bacteria such as E. coli, which can be transferred to children through contact with the animal or its faeces. If the child then goes on to eat, drink, or put their hands near their mouth, without washing their hands, there is a real risk of serious infection.
Urging everyone to follow simple hygiene steps to avoid spoiling anyone’s fun, Malcolm Downey who heads HSENI’s farm safety team said: “Anti-bacterial gels and wipes alone are not a substitute for properly washing your hands.”
Sorry Malcolm, it’s not that simple.
Our paper on human-animal interactions published in Zoonoses and Public Health, includes a 2-page checklist for parents, and the teachers who book these events.
Gonzalo Erdozain, Kate KuKanich, Chapman and I have all seen microbiologically terrible practices at petting zoos or in homes, and read about them from around the world, so we thought, maybe we should try and provide some guidance.
The uniting factor is we all have kids, and in my case, grandkids, and keep adding more.
In Brisbane, they have the Ekka, something like the Texas State Fair. The petting zoo was absolute madness, and after living in Brisbane and hanging out with micro-types I got the message, don’t go to the Ekka, you’ll get sick. We didn’t go in 2013: 49 people, primarily kids, got sick from E. coli O157 (and in typical Queensland style, the outbreak has never been written up, there has been no follow-up, nothing; guess it would be bad for agriculture).
North Carolina has had repeated and terrible outbreaks.
As a father of five daughters, I’ve had many requests over 20 years to go on a school trip to see the animals. As a food safety type, I’ve been routinely concerned about best practices. The other parents may dislike microbiology, but I’m concerned with the health and safety of the children involved.
Best practices for planning events encouraging human-animal interations
Zoonoses and Public Health 62:90-99
Erdozain , K. KuKanich , B. Chapman and D. Powell, 2015
http://onlinelibrary.wiley.com/doi/10.1111/zph.12117/abstract?deniedAccess Educational events encouraging human–animal interaction include the risk of zoonotic disease transmission. ‘It is estimated that 14% of all disease in the USA caused by Campylobacter spp., Cryptosporidium spp., Shiga toxin-producing Escherichia coli (STEC) O157, non-O157 STECs, Listeria monocytogenes, nontyphoidal Salmonella enterica and Yersinia enterocolitica were attributable to animal contact. This article reviews best practices for organizing events where human–animal interactions are encouraged, with the objective of lowering the risk of zoonotic disease transmission.
The township council on Tuesday is scheduled to introduce an ordinance that would stiffen penalties for restaurants with a history of failing health inspections, imposing fines as much as three times the current amount and imposing mandatory closures.
Under the current model, restaurants that receive a “conditionally satisfactory” rating, which denotes health issues that need to be addressed, are charged a $250 reinspection fee after each of their second, third and fourth consecutive violations.
Township health officer Jeff Plunkett said that some businesses do not take the $250 fee seriously: One owner simply tried to hand a health inspector $250 in cash from his wallet.
“We’ve come to the conclusion that people just pay it,” Plunkett said in February.
The new ordinance would impose steps in the reinspection fees: $250 on the second consecutive offense, $500 on the third and and $750 on the fourth. After four consecutive offenses, the township will shut down the restaurant for a minimum of two days — even if the violations are resolved quickly.
“You keep trying to educate the ownership that they have a responsibility to every customer who walks through their door. It cannot be taken lightly.”
About 15 years ago, I was a goofy grad student without a lot of ambition.
I had an interest in infectious diseases, genetics and how people talked about risk. Not necessarily in that order.
I found Doug and he set me up with a project working with a bunch of greenhouse tomato and cucumber producers.
His advice was watch everything, ask questions and write it down or you will forget it.
Being on farms and in processing plants I learned about the real challenges that folks encounter when they try to manage risks and ended up finding a passion for food safety. I saw food safety in action daily.
Over the past few weeks I’ve spent a bunch of time out of my office doing food safety stuff in the real world like working with chefs on HACCP plans, visiting storage facilities, providing risk communication messages for an outbreak.
But the most food safety fun I’ve had recently was talking to a friend’s Brownie troop about micobiology and handwashing. Grad students Natalie Seymour, Nicole Arnold and Katie Overbey did the heavy lifting, showed the girls what science is and were excellent scientist role models. I just showed up.
But I guess my handwashing prowess blew a mind or two (above, exactly as shown).