Ora Rhine & Ali Galzki '09

Effectiveness of a UV-C Light Wand Compared to Clorox Wipes or Dish Soap in Sanitizing Cutting Boards

Ultraviolet-C (UV-C) light is commonly used as a sanitizing agent in hospitals, commercial buildings and water treatment plants.  UV-C light wands are being highly touted for home use in the areas of personal care items such as toothbrushes, computer keyboards, bedding and food safety in the kitchen.  Variation exists in the commercially available UV-C light wands in the cost - ranging from $30 to $200 - and in the strength of the wands.  The most effective wavelength frequency for microbial destruction is between 220nm and 280nm.  UV-C light alters the genetic structure of thin-walled microbes resulting in death.  

Purpose:  To determine the effectiveness of the Germ Guardian LW18 UV-C light wand when compared to Clorox Wipes and Dawn dish soap in sanitizing cutting boards typically used in the kitchen. 

Methods:  Two wooden and three plastic cutting boards were labeled and sectioned into three sections - Clorox Wipes, Dish Soap and UV-C Light.  One wooden board was contaminated with raw chicken and one wooden cutting board was contaminated with raw ground beef.  The plastic cutting boards were individually contaminated with raw chicken or raw ground beef. The sections were sanitized, one at a time, as labeled.  After sanitizing the section, samples were taken using 3M Quick Swabs and the media was immediately transferred to 3M Petrifilm Aerobic Count Plates.  The effectiveness of the Germ Guardian UV-C light wand was further assessed at two and three times the recommended length of exposure (twenty and thirty seconds.)  The Petrifilms were incubated at 37 degrees Celsius, with observations at 24 and 48 hours. 

Results: There was virtually no bacterial growth after sanitizing with the Clorox Wipes.  There was some growth with the UV-C light at 10 seconds (the recommended exposure) but less growth with the UV-C light at 30 seconds.  There was substantially more growth observed with the Dawn dish soap and hot water.  

Conclusions:  The Clorox Wipes were the most effective sanitizing agent.  The Germ Guardian LW18 UV-C light wand was not as effective at sanitizing cutting boards, when used at the recommended length of exposure, as the Clorox Wipes.  It took three times the recommended exposure to achieve the results the manufacturer claims at 10 seconds.  Dawn dish soap and hot water were not effective at sanitizing the cutting boards.

Ora Rhine and Ali Galzki presenting their research at the Minnesota Dietetic Association Annual Meeting, May 7, 2009, St. Cloud, MN

Ora Rhine and Ali Galzki presenting their research at Scholarship and Creativity Day

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Effectiveness of a UV-C Light Wand Compared to Clorox Wipes or Dish Soap in Sanitizing Cutting Boards