Handwashing for nerds: Are those Dysan jet dryers better than paper towel?

Amy, Sorenne and I spent a long last weekend in San Francisco, where Amy conferenced, I had some meetings, but mainly just hung out with the kid (three pirates and a little girl, right).

The washrooms at the San Francisco airport featured the Dysan airblade, billed as the “fastest, most hygienic hand dryer.” Says so right on the machine. And it’s certified by NSF as “tested, certified, hygienic.” Says so right on the machine.

My bowels are in a state of flux when traveling so I had several opportunities to try out the newfangled machinery, that sounds like an airplane is taking off below your fingertips.

We have maintained, based on our reading of the available literature, that proper handwashing, entails:

• wet hands with water;
• use enough soap to build a good lather;
• scrub hands vigorously, creating friction and reaching all areas of the fingers and hands for at least 10 seconds to loosen pathogens on the fingers and hands;
• rinse hands with thorough amounts of water while continuing to rub hands; and,
• dry hands with paper towel.

Water temperature is not a critical factor — water hot enough to kill dangerous bacteria and viruses would scald hands — so use whatever is comfortable.

The friction from rubbing hands with paper towels helps remove additional bacteria and viruses.

I did a cursory search to find some data on the Dysan thingy, and found a study comparing paper towel, regular blow dryers, and a Dysan-type jet dryer that was published in 2008.

Those authors state:

“The jet air dryer showed that there were significant differences (although not as great as for the fingerpads) between the towels and both types of dryer. Again, the superior performance of the towels in reducing bacterial numbers was confirmed. As for the fingerpads, the jet air dryer performed better than the warm air dryer in not increasing mean bacterial count on the palms as much but this difference was not significant.

“Therefore, the manufacturer’s claim that the tested JAD is the “most hygienic hand dryer” is confirmed, especially for fingerpads and assuming that the term “hand dryer” refers to electric devices only because its performance in terms of the numbers of all types of bacteria remaining on the hands of users compared to paper towels was significantly worse. …

“It is well known to microbiologists that air movements encourage the dispersal and transmission of microorganisms and increase the chances of the contamination of materials or persons in any situation. This makes paper towels, where little air movement is generated, the most hygienic option tested in this respect followed by the warm air dryer and, lastly, the jet air dryer.”

The friction from rubbing with paper towel is particularly effective at reducing microbial populations; yet many of these public bathrooms have signs proclaiming that electric dryers of whatever kind are better, and save the trees. Oh, and I should hear from someone at Dysan or NSF – public claims need to be backed with public data.

Maybe I’ll just stay at home.

Say it loud, say it proud, blow dryers suck

Daughter Courtlynn – the 14-year-old – arrived from Canada last night for a last-minute weekend bonding session with Sorenne. And Amy. And me?

While waiting for Courtlynn’s plane to arrive in Kansas City – it’s not her plane, it’s Air Canada’s plane, but she was on it – we killed some time at the Zona Rosa outdoor mall near the airport. We found the restroom with the diaper-changing facilities and saw the biggest, eco-BS hand drying sign I’ve ever seen.

The friction from rubbing with paper towel is far more effective at reducing microbial populations than dispersing the bugs everywhere with a blow dryer that doesn’t really dry hands. The County health inspectors may want to check this out.

New hand dryer eco-friendly, food safe

I’ve waited a whole month for this Saturday to roll around. For weeks, I’ve been rinsing, drying, crushing, and collecting our cans, bottles, and boxes in anticipation. This Saturday is the day the county picks up our recycling. I have to drive my tubs to the library parking lot, but I don’t mind. I’m happy to be counted among those who choose to waste less. This reflects one particular side of my personality.

Another side is evident when I wash my hands: I soap up my palms and fingertips. I get between my fingers and up my wrists. After I rinse away the soap, I dry them thoroughly.

And this is the point where the two collide: When I go to dry my hands (and am not at home where clean cloth towels are available), I always reach for the paper towels over a blow dryer.

I know many trees are felled in the making of single-use paper towels, but blow dryers are disgusting: They collect microbes that may have been aerosolized when the toilet was flushed and then blow them onto your hands.

At least, most blow dryers do. HACCP Australia thinks the Dyson Airblade hand dryer can effectively dry hands without recontamination.

Australia Food News reports that the Dyson Airblade is the first hand dryer to be approved for use in food handling areas. AFN explains,

“Using high velocity sheets of unheated air, hands are dried in just ten seconds while, at the same time, 99.9% of bacteria and mould is removed from the air using HEPA filtration…The dryer, unlike conventional warm air hand dryers, does not blow bacteria back onto freshly washed hands nor use a heating element that can induce bacterial growth.”

As an added ecological bonus, the Dyson Airblade uses up to 80 per cent less energy compared with conventional hand dryers.

“Recently unveiled in Australia, the Dyson Airblade hand dryer has already had local success by receiving a New Product Award at its first public launch. It has now been introduced in food manufacturing areas at Cargill’s, Kellogg’s, Fletcher’s International, KFC, Tabro Meats, Wingham Beef and George Weston Food’s Tip Top bakeries, as well as a number of kitchens at McDonalds Restaurants.”

Until these are available in all the kitchens and public bathrooms I visit (and the data shows up on their microbial safety), I try to strike a balance between food safety and eco-friendliness: I use one paper towel to its fullest (two, if necessary), and avoid grabbing a handful out of assumption that they’ll be needed.

I hate assumptions.

Obama says – dude, wash hands to contain swine flu

When asked about swine flu – oh, sorry, the H1N1 flu – U.S. President Barack Obama said during his prime-time 100-day press commencement conference that handwashing and staying at home if sick were key to controlling any potential spread of flu.

As we’ve said, proper handwashing with the proper tools — soap, water and paper towel — can significantly reduce the number of foodborne and other illnesses, even the emerging swine flu.

The steps in proper handwashing, as concluded from the preponderance of available evidence, are:

• wet hands with vigorously flowing water;

• use enough soap to build a good lather;

• scrub hands vigorously, creating friction and reaching all areas of the fingers and hands for at least 10 seconds to loosen pathogens on the fingers and hands;

• rinse hands with thorough amounts of water while continuing to rub hands; and

• dry hands vigorously with paper towel.

If any of the tools for handwashing are missing, let someone know.

However, even with reminders and access to the proper tools, not everyone will practice good hygiene. Those signs that say, ‘Employees Must Wash Hands’ don’t always work. We’re working in settings like high schools and hospitals to figure out the best way to not only tell people to wash their hands, but to use new media and messages to really compel individuals to wash their hands.

A video is available at:

and a poster at

Washing (and drying) your hands and grocery cart handles

Marcia Patrick, director of infection prevention and control for a health system in the state of Washington (and a spokeswoman for the Association for Professionals in Infection Control and Epidemiology), pointed out in the Washington Post this month,

"All the different things we touch in the regular course of our day can contain germs,” including grocery cart handles.

I tend to refer them as “pathogens,” but I agree: they’re everywhere. As such, I was quite excited to have my first experience with grocery cart wipes.

I, an avid user of lemon-scented disinfecting kitchen wipes, noticed a little stand in my local grocery store about a year ago that held a container of sanitizing wipes to use on the handle of the cart after the cart’s previous user (or user’s child) was done sneezing/coughing/drooling/chewing on it.

That container was empty for my entire senior year of college.

But last night, while shopping in a new location, I spotted another stand—this one complete with pre-moistened wipes! (That’s my husband, at right, wiping the cart handle.)

And they were certainly moist; I spent the rest of my shopping experience getting disinfecting juice on my grocery list.

Perhaps one wipe is intended to sanitize an entire cart, rather than just the handle…

Washing your hands is extremely important to avoid getting sick. Drying is an essential aspect.

Pathogens stick better to wet hands (and grocery cart handles). Drying them after washing will significantly reduce what you may pick up.

Paper towels are the ideal tools, as all handwashing agents are more effective when a paper towel is used for drying. (See Doug’s quote in a USA Today article that ran yesterday.)

Blow dryers are just disgusting. They collect pathogens that may have been aerosolized when the toilet was flushed and blows them onto your hands. (Yet another instance where ecological friendliness does not equate to microbiological safety.)

E-mail me for the refs, if you’d like. And don’t eat poop, people: Dry your freshly-washed hands and grocery carts.


Burger King: Paper towels in the bathroom please

I have been working for Doug for almost 4 months now. I am happy to say that I have learned a lot.

One of these things is proper hand-washing. So every time I go to a public restroom I keep my eyes open and watch every detail.

I often notice when someone skips the hand-washing step or someone who doesn’t dry up afterwards.

Just the other day I went during my lunch break to Burger King to grab a double cheeseburger. I went to the restroom first, and when I was in one of the stalls, a woman came in with her kid, telling him to scrub his hands. I heard water running. Then they just left – but I didn’t hear any paper tearing.

Well, there wasn’t any. No, BK didn’t just run out of paper. They didn’t have a paper towel dispenser at all. Only a drier. And a very lousy one. The evidence:

BK employees should not only wash their hands, but dry them as well.

Frustrated I left, and hesitated: Can I still eat my burger, knowing that employees (or at least the women) don’t dry their hands properly in that establishment?

No more BK cheeseburgers for me. Doug wrote in a letter:

Blow dryers should not be used because they accumulate microorganisms from toilet aerosols, and can cause contamination of hands as they are dried by the drier (Knights, et al., 1993; Redway,et al., 1994).

Every bathroom should have running water, soap and paper towel.

Check out this other BK incidence: Restaurant sinks are not bathtubs