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PURE Abstract March 2017-Effective Reduction of Bacteria

PURE Abstract March 2017-Effective Reduction of Bacteria

Wednesday, March 15, 2017

Effective Reduction of Bacteria from Surfaces Using Bleach and Silver Dihydrogen Citrate Solutions


Author: Andrew Duong


Originally published on Please cite as:

Duong, A (2017) Effective Reduction of Bacteria from Surfaces Using Bleach and Silver Dihydrogen Citrate Solutions. 3: 1-7


Study Rationale:

The cleaning of hospital surfaces relies on effective chemicals to reduce the presence of pathogens. However, long-term exposure to these chemicals has been shown to have adverse effects on healthcare workers. In this study, the effectiveness of traditional hospital disinfectants will be evaluated against novel, non-caustic disinfectants.


There is little consensus in healthcare when it comes to cleaning procedures and product classes. In recent years, the purpose of cleaning has switched to the reduction of healthcare-acquired infections (HAIs). These infections can be deadly to at-risk patients in hospital, and the reduction of dangerous bacteria and viruses can severely inhibit their spread among patients and staff. However, determining the best choice for cleaning is difficult, as there is little comparative testing between chemicals.

Bleach (sodium hypochlorite) is most commonly employed in hospitals, as it is an effective disinfectant, capable of removing most bacteria and viruses from surfaces.  However, current literature reflects that the overuse of this caustic compound may result in adverse health effects in healthcare workers who use it regularly. Thus, there is a push towards the use of less harmful, yet still effective cleaning compounds.


All testing was performed at the Jacobs Institute, Buffalo Niagara Medical Campus. Briefly, three surface types (plastic, stainless steel and textiles) were contaminated with either Staphylococcus aureus or Escherichia coli. Water, dilute bleach, or a silver dihydrogen citrate (SDC, PURE Biosciences Inc.) was applied to these surfaces, wiped with a microfiber cloth and the bacteria that remained on the surface were quantified.

Results and Discussion:

The reduction of E. coli and S. aureus on plastic, stainless steel, and textile (mattress cover) surfaces by bleach and SDC were comparable, resulting in a greater than 9-fold log reduction. The use of microfiber in cleaning was extremely effective for removal of bacteria, even when used with water alone. However, due to potential contamination of neighbouring surfaces, the use of a disinfectant needs to be employed. Since bleach and SDC had similar efficacies in bacterial reduction, SDC, also known as PURE® Hard Surface (PURE Biosciences, Inc.) is a viable alternative that is non-caustic, safe for long term exposure (level IV toxicity rating - practically non-toxic and not an irritant), and effective in reducing the presence of harmful pathogens.

Responsible cleaning should be a priority for healthcare systems as it affects not only patients, but also workers. Alternatives to bleach can be similarly effective, without compromising public safety.