Is Hand Sanitizer Better Than Soap

Hand Sanitizer Vs. Hand Soap Experiment

In this experiment we tried to find out which cleans hands better, hand sanitizer or hand soap.

Monday, October 13, 2014

Step by step video demonstration

Posted by Dan Eschenfelder at 3:50 PM No comments:

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PHOTOS

PURPOSE

The purpose of my experiment is to find out if hand sanitizer works as well or better than soap and water for getting germs off your hands.
The reason why this is important is because that a lot of people use hand sanitizer when their hands are dirty and think that it is as good at getting rid of germs as soap and water.

HYPOTHESIS

Hypothesis: Washing your hands with soap and water will remove more bacteria than using hand sanitizer.

RESEARCH ON THIS TOPIC

Cameron
Science Fair Research Paper 2^nd period
September 25, 2014

Gee, germs sure are gross: Soap versus hand sanitzer

The first thing I did was look for information on washing your hands using soap and hand sanitizer.I went to the Google Kids search site and typed in the keywords “wash hands soap hand sanitizer.” One of the websites I found was from the CDC or the Centers for Disease Control. The site is http://www.cdc.gov/handwashing/show-me-the-science-hand-sanitizer.html. My mom and dad said the Centers for Disease Control is a good source for information about illnesses. The Centers for Disease Control says that washing your hands with soap is better than using hand sanitizer. It says that the best way to clean germs off your hands is to use soap and water. If you can’t use soap and water, they say you can use hand sanitizer as long as it is 60% alcohol. It also says that is your hands are really greasy that hand sanitizer won’t work as good as soap because soap is better at getting off grease and dirt.

Another website that I found that came up when I searched “wash hands soap hand sanitizer” was a website called About Education. The website is called “Hand sanitizers vs. soap and water.” The website is http://biology.about.com/od/microbiology/a/handsanitizers.htm. They say that the companies that make hand sanitizer tell people that hand sanitizer kills 99.9% of germs on your hands. But the About Education people say that may not be true. They say that the way hand sanitizers work is that they strip oils off of your hands and keep bacteria from getting on them. But a scientist says that the kind of bacteria the hand sanitizers keep off your hands is not the kind that makes you sick. They also say that people who work in restaurants have to use soap to clean their hands instead of hand sanitizer.

The About Education website also says that regular soap is just as good as antibacterial soap when you are washing your hands. That makes me think that I should add that to the experiment and test regular soap, hand sanitizer, and antibacterial soap.

I got on to the regular Google and searched “hand washing” so I would know the right way you are supposed to wash your hands and use hand sanitizer for my science fair project. I found a website for the Mayo Clinic. My mom and dad said the Mayo Clinic is a famous hospital that treats people with a lot of different kinds of diseases and they have a lot of good doctors and scientists. The website is http://www.mayoclinic.org/healthy-living/adult-health/in-depth/hand-washing/art-20046253. They say that you need to wash your hands for a lot of reasons including going to the bathroom, blowing your nose, before you make food, and after you are around sick people. They say you should wash your hands for 20 seconds with soap and water. They say if you use hand sanitizer if there is no soap and that it should have 60 percent alcohol in it. The say you should use enough to get your hands really wet and then rub your hands together until they are dry.
Another place I checked for resources for my science fair project was by looking at other projects people have done about soap versus hand sanitizer. In the regular Google, I used the keywords “soap versus hand sanitizer project” and I found some good science projects. One that was really good was at the website http://www.virtualsciencefair.org/2013/whit13k. The website put in the hypothesis, the method, the results, pictures, and a lot of good details. The person who did the site talked about counting bacteria. There was a list of references, too of resources that person used. They found out that soap was better. I want to see what I will find out and learn how to do the experiment.

MATERIALS

For this experiment we used eight Agar plates, a hand-made incubator, a thermometer, anti-bacterial hand soap, hand sanitizer (60% alcohol+), and a bag of Doritos chips.

Agar plates purchased online at: AGAR PLATES
Fish tank and tank thermometer purchased at PetSmart
Anti-bacterial hand soap purchased at Target
Hand sanitizer purchased at Target
Doritos chips purchased at grocery store

PROCEDURE

· On day one, I put out four agar plates and labeled them.

· I had two people put their unwashed hands onto different agar plates.

· I had person one wash their hands with soap and water using the recommendations for hand washing I found online. I had person two clean their hands with hand sanitizer using the recommendations I found online for hand sanitizer use.

· I had both people put their clean fingers from one hand onto different agar plates. I put all the plates into the incubator for 24 hours.

· The next day, I looked at the plates to see the colonies of bacteria. I compared the difference between the unwashed hands, the hands that used soap and water, and hands that used hand sanitizer.

· I recorded what I saw and counted the colonies of bacteria.

· On a different day, I had two more people repeat the experiment exactly, but this time with greasy food stains on their hands.

DISCUSSION

The results of my study were like the results of other studies. Soap and water got more bacteria off hands than hand sanitizer. In my study, the soap got off about 17% more bacteria than the hand sanitizer. Because I had to count the bacteria by just looking at it and not using a microscope, I was just eyeballing it and could have made some mistakes. It was pretty obvious that there was less bacteria on the plate from the person who used the hand soap from just looking at it but science is about testing things and coming up with data. I learned a lot about counting bacteria colonies. It is hard and you have to really concentrate. With the second series, I had to use a grid to try to count the colonies because they were really small. In that case, I used some graph paper. I could have left the dishes in little longer maybe so they could grow some more. Next time, I might try to get a scientist to help me count the bacteria or do some more research on counting bacteria. I would also do one more series next time, which would take a little more time.

RESULTS

October 8^th, 2014: I had two people to do the experiment. Both people had not washed their hands in at least an hour. Both people put their fingers onto the first set of petri dishes. The soap person then washed her hands and put her hands into a new dish of agar. The hand sanitizer person cleaned his hands then put his fingers into a new dish. I put all dishes into the incubator at 8:45 pm.

October 9, 2014 8:45 pm: I removed the agar plates after 24 hours and looked at the bacteria. You could see there was more bacteria on the agar plate for the person that used the hand sanitizer. The bacteria looked round and yellowish. A lot of it was smooth but some were kind of bumpy. I counted the bacteria colonies without using a microscope, just using my eyes. Some of the agar was cracked. I guess because the people pressed too hard.

C1-before hand sanitizer-15 colonies
C1-after hand sanitizer-8

C2-before soap-11
C2-after soap-4 colonies

Hand Sanitizer: Number of Bacterial Colonies

Before After Difference % Reduction

15 8 7 47%

Soap: Number of Bacteria Colonies

Before After Difference % Reduction

11 4 7 64%

So in this first series the soap worked better.

October 11, 2014 1:17pm

I did the same procedure except both people had just eaten Doritos nacho cheese chips and wiped their hands with only a napkin. I put all four labeled plates into the incubator and waited 24 hours.

October 12, 2014 1:45 pm

I took out the plates. The imprints looked a little different. The color looked a little different than the first series. The bacteria looked like snowflakes on the ground. Some of them were smaller and not in as many big circles or clusters like the first series. It was harder to count. This time again the soap worked better at getting off the germs.
Before After Difference % Reduction
C1 sanitizer
24 15 9 37.5
C2 soap

22 10 12 54.5

GRAPHS

CONCLUSION

My hypothesis was supported in this experiment. Using soap and water got rid of more bacteria than using hand sanitizer. In this study, the soap got rid of about 17% more bacteria than the hand sanitizer, even for different kinds of dirt (normal, cheesy food). This should let people know that hand sanitizer does get rid of some bacteria on your hands, but that using soap and water is better if you can.

BIBLIOGRAPHY

http://biology.about.com/od/microbiology/a/handsanitizers.htm

http://grad.bio.uci.edu/ecoevo/ahebling/Research/GK-12_files/SoapSanitizer_Presentation.pdf

http://www.cdc.gov/handwashing/show-me-the-science-hand-sanitizer.html.

http://www.ehow.com/how_4500194_grow-bacteria-agar.html

http://www.mayoclinic.org/healthy-living/adult-health/in-depth/hand-washing/art-20046253

http://www.sciencebuddies.org/science-fair-projects/phpBB3/viewtopic.php?f=25&t=6238

http://www.scienceenterprises.com/growingbacteria.aspx

http://www.virtualsciencefair.org/2013/whit13k

ACKNOWLEDGMENTS

I would like to thank my mom and dad for all the work they did helping me with my project.

SHARE YOUR RESEARCH

The "COMMENTS" section of this blog is for anyone wishing to share their research, findings, and how they furthered this experiment.

Please feel free to share links, post images, and any other information you found that can help anyone wishing to do this experiment.

CHANGES TO EXPERIMENT

Here are some of the things I'd do differently...

I would have the same person do each agar plate so each hand has the same pressure on the agar plate, they are the same size hands, and they will wash in the most similar way.

I would use a microscope to accurately measure and count bacteria colonies. Counting with the naked eye isn't as accurate.

FUTURE RESEARCH

Here are some suggestions for further research or an expansion on this research...

Someone may want to measure the difference in different levels of hand sanitizer. We used 60% alcohol. You could use different hand sanitizers with different levels of alcohol.

Since fats and sugars are said to be less effective in removing with hand sanitizer, someone may want to measure the difference between the removal of fatty or sugary foods using hand sanitizer.