Hand dryers might be better for the environment; worse for limiting disease spread

I like to write at Starbucks. There’s something about the background activity and lattes, mixed with Neil Young on my iPod, that helps me focus. I hit up a somewhat new outlet in Raleigh today and needed a restroom break. After washing my hands I looked around the bathroom for paper towels and all I could find was an air dryer (right, exactly as shown). I wanted paper towels, because using them matters; drying friction helps remove pathogens.

I don’t like blow dryers because the literature shows they accumulate microorganisms from toilet aerosols, and can cause contamination of hands as they are dried by the dryer (Coates et al., 1987; Knights, et al., 1993; Redway,et al., 1994). In 2010, Anna Snelling and colleagues at the University of Bradford (UK) also showed that drying with a blow dryer can recontaminate hands and rubbing with paper towel was the most effective method to reduce pathogens.

Handwashing and food service food safety guru Pete Snyder at the St. Paul-based Hospitality Institute of Technology and Management summarized key aspects of handwashing and drying . Pete says that after hands are washed and rinsed, they must be thoroughly dried and cites data that shows 1-2 log reduction of pathogens from drying. Water and soap loosen the attachment of pathogen to hands. A rinse step dilutes what has been loosened but drying (and the friction associated) is the next step that matters – and the bugs have to go somewhere; I’d rather that be a paper towel instead of being blown all over my pants.

Pete also notes that it is also apparent that many individuals do not dry their hands thoroughly when using a blow dryer; hence, moisture, which is conducive to microbial growth, remains on hands, or people dry their hands on their clothing.

Starbucks, proper handwashing requires guest access to the proper tools – and that means vigorously running water, soap and paper towel.

Coates, D., D. N. Hutchinson, and F. J. Bolton. 1987. Survival of thermophilic campylobacter on fingertips and their elimination by washing and disinfection. Epidem. Inf. 99:265-274.

Knights, B., C. Evans, S. Barrass, and B. McHardy. 1993. Hand drying – A survey of efficiency and hygiene. The Applied Ecology Research Group, University of Westminster. London, UK.

Redway, K., B. Knights, Z. Bozoky, A. Theobald, and S.Hardcastle. 1994. Hand drying: A study of bacterial types associated with different hand drying methods and with hot air dryers. Applied Ecology Research Group, University of Westminster. London, UK. 14. Brodie, J. 1965. Hand hygiene. Scot. Med. J. 10:1:115-125.
 

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About Ben Chapman

Dr. Ben Chapman is an associate professor and food safety extension specialist at North Carolina State University. As a teenager, a Saturday afternoon viewing of the classic cable movie, Outbreak, sparked his interest in pathogens and public health. With the goal of less foodborne illness, his group designs, implements, and evaluates food safety strategies, messages, and media from farm-to-fork. Through reality-based research, Chapman investigates behaviors and creates interventions aimed at amateur and professional food handlers, managers, and organizational decision-makers; the gate keepers of safe food. Ben co-hosts a biweekly podcast called Food Safety Talk and tries to further engage folks online through Instagram, Twitter, Facebook, YouTube and, maybe not surprisingly, Pinterest. Follow on Twitter @benjaminchapman.
  • Melynda

    Proper handwashing also requires employee access to the proper tools