Best Hand Soap for Effective Handwashing and Killing Bacteria
Kiran David Singapogu
I. RESEARCH PROBLEM
The spread of COVID-19 has made us more conscious of our need to be clean. For most of us, this means prioritizing the washing of our hands with soap and water regularly. Recently during the process of washing my hands, it crossed my mind that there are many variables that could play a part in the effectiveness of this process.
II. RESEARCH QUESTION
I wonder what handwashing products are most effective for killing bacteria?
III. BACKGROUND RESEARCH
In 1864, Hungarian doctor Ignaz Semmelweis, while working a hospital maternity ward, discovered that when a handwashing regimen was implemented, death rates dropped. Unfortunately, other doctors disliked the practice of handwashing and boycotted it. During the Crimean War, Florence Nightingale implemented procedures for sanitization including handwashing. This lead to improved health for wounded soldiers. Gradually, the public has become more aware of the need for handwashing. However, it wasn’t until relatively recently, in the 1980’s, that there has been a widescale push for general handwashing when the United States Center for Disease Control and Prevention endorsed hand hygiene guidelines which have been increasingly understood and implemented by the public.
Handwashing products such as hand soap, hand sanitizer and antibacterial handwipes work by killing the bacteria. Antibacterial hand soap breaks the outer layer of the bacteria and kills it. It is then rinsed off with running water. Hand sanitizer works by shaking up the bacteria and viruses and bacteria on the surface of our skin in almost the same way an earthquake demolishes a building. The viral and bacterial particles are still present on the surface of our hands but are no longer living because they have been broken apart.
The United States Center for Disease Control and Prevention provides guidance and recommendations for general handwashing. It is recommended that individuals wash their hands before and after eating, or preparing food, after using the bathroom, and in a variety of other situations. They provide the following guidelines for effective handwashing:
1. Wet your hands with clean, running water (warm or cold), turn off the tap, and apply soap.
2. Lather your hands by rubbing them together with the soap. Lather the backs of your hands, between your fingers, and under your nails.
3. Scrub your hands for at least 20 seconds. Need a timer? Hum the “Happy Birthday” song from beginning to end twice.
4. Rinse your hands well under clean, running water.
5. Dry your hands using a clean towel or air dry them.
IV. HYPOTHESIS
Cleaning hands with liquid antibacterial hand soap and water, will be the superior method for handwashing compared to handwashing using bar soap, vinegar, hand sanitizer or antibacterial wipes.
V. PROCEDURE
1. Take six pre-poured sterilized petri dishes. Using a Sharpie marker, label each petri dish with a number one through six.
2. Take petri dish labeled one and touch with unwashed hands.
3. Wash hands for twenty seconds (using a timer) following CDC recommendations.
4. With left hand, touch a light switch, doorknob, writing utensil, tabletop and chair frame making maximum contact with each object.
5. Wash hands for twenty seconds (using a timer) following above CDC recommendations using liquid antibacterial hand soap. Allow hands to air dry.
6. Touch petri dish number two using left hand thumb, index finger and middle finger, making maximum possible contact.
7. Repeat steps fourteen through sixteen for four more trials and wash hands using: bar soap, vinegar, hand sanitizer and antibacterial hand wipes and use petri dishes three through six.
8. Cover petri dishes with lids and place in a clean box. Store in a clean, dry location away from sunlight.
9. Observe and photograph at noon daily.
VI. MATERIALS LIST
1. Six petri dishes
2. Sharpie
3. Timer
4. Light switch
5. Doorknob
6. Writing utensil
7. Tabletop
8. Chair
9. Liquid antibacterial hand soap
10. Bar soap
11. Vinegar
12. Hand sanitizer
13. Antibacterial wipes
VII. RISK AND SAFETY
While cultures are growing, petri dishes will be tightly sealed and stored in a controlled environment so that no cultures are released into the environment.
It is critical to dispose of used petri dishes properly. In order to destroy any cultures on petri dishes a small amount of bleach solution will be applied prior to disposal.
VIII. DATA ANALYSIS METHOD
I will take pictures of each sample on the hour for seven days. At the end of seven days, I will assess the growth of cultures using two methods. First, I will visually observe each petri dish and count how many different kinds of cultures are visible and record the number in a table. Second, I will visually observe each petri dish and assess the percentage of the dish that is covered in visible growth. I will record the results in a table. After assessing all handwashing agents by (1) visible number of cultures and (2) percentage of coverage, I will calculate the final score of each handwashing agent.
IX. BIBLIOGRAPHY
“Survey Reveals U.S. Handwashing Trends.” Professional Safety, vol. 65, no. 2, Feb 2020, p. 9.
Hunter, Beatrice Trum. “So, How Important Is Hand Washing?” Consumers’ Research Magazine, vol. 83, no. 4, Apr. 2000, p. 23.
Munson, Marty. “5 Myths About Hand Washing.” Prevention, vol. 70, no. 11, Nov. 2018, pp. 42-45.
Samonte, Pamela Rose V., and rhea U Vallente. Hand Hygiene Compliance.” Salem Press Encyclopedia of Health, 2020.
Freeman, Matthew C., and Bethany A. Carusco. “Comment on ‘Global Access to Handwashing: Implications for COVID-19 Control in Low-Income Contries.’” Environmental Health Perspectives, vol. 128, no. 9, Sept. 2020.
“Improper Handwashing Spreads Bacteria.” USA Today Magazine, vol. 147, no 2879, Aug. 2018, pp. 4-5.
“Hand Sanitizer.” Britannica School, Encyclopedia Britannica, 22 Aug. 2019.
“The Global Handwashing Partnership.” Go to The Global Handwashing Partnership., 2017, globalhandwashing.org/about-handwashing/history-of-handwashing/.
“When and How to Wash Your Hands.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 24 Nov. 2020, www.cdc.gov/handwashing/when-how-handwashing.html.
X. ANALYSIS OF DATA OR RESULTS
According to my experiments, vinegar performed best compared to other cleaning agents for handwashing. Hand sanitizer and wipes tied as the second most effective cleaning agents. Liquid hand soap was the third most effective cleaning agent and bar soap was the least effective cleaning agent. As expected, unwashed hands performed poorest in my experiment.
|
|
Trial 1 |
Trial 2 |
Trial 3 |
Average |
|
Unwashed hands |
9 |
9 |
7 |
8.33 |
|
Liquid Hand soap |
5 |
3 |
5 |
4.33 |
|
Bar Soap |
6 |
7 |
8 |
7 |
|
Vinegar |
5 |
2 |
5 |
4 |
|
Hand Sanitizer |
4 |
5 |
4 |
4.33 |
|
Wipes |
3 |
6 |
3 |
4 |
|
|
Number of cultures |
Percentage of coverage |
Final score |
|
Unwashed hands |
4 |
6 |
5 |
|
Liquid Hand soap |
2 |
4 |
3 |
|
Bar Soap |
3 |
5 |
4 |
|
Vinegar |
1 |
1 |
1 |
|
Hand Sanitizer |
2 |
2 |
2 |
|
Wipes |
1 |
3 |
2 |
|
|
Trial 1 |
Trial 2 |
Trial 3 |
Average |
|
Unwashed hands |
95% |
90% |
80% |
88.3% |
|
Liquid Hand soap |
90% |
15% |
90% |
65% |
|
Bar Soap |
85% |
50% |
95% |
77% |
|
Vinegar |
45% |
15% |
75% |
45% |
|
Hand Sanitizer |
50% |
15% |
95% |
53% |
|
Wipes |
30% |
55% |
80% |
55% |
XI. CONCLUSIONS
My hypothesis was that cleaning hands with liquid antibacterial hand soap and water would be the superior method for handwashing compared to handwashing using bar soap, vinegar, hand sanitizer or antibacterial wipes. My results contradicted my hypothesis.
My experiment went smoothly and I didn’t encounter any major problems. More trials would have helped to provide more precise results. Additionally, it would have been helpful to view my cultures under a microscope in order to more precisely identify and quantify them.
I would like to thank Mrs. Angie Mullinax and my parents for their assistance with this research.
