Which+Cleaning+Method+Keeps+Surfaces+the+Cleanest?

 - IV-Antibacterial formula liquid sprays, wipes, or aerosol sprays.  - DV-The average surface area on the petri dish covered by bacteria.
 * Title: ** Do Disinfecting Wetwipes, Liquid Sprays, or Aerosol Sprays Work Best to Kill Bacteria on a Surface?


 * Abstract:**

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Our research project is about what type of cleaning method, antibacterial wipes, liquid formula sprays, or aerosol sprays, work best to clean a surface. We believe this is an important topic because it could help prevent sicknesses. Our experiment was carried out by dividing a surface,with equal amounts of bacteria, into quadrants with cardboard barriers, and then applying the cleaning products to certain quadrants, and growing bacteria samples from each quadrant before and after. We then compared the numbers. =====


 * Purpose: ** It is well-known knowledge that bad bacteria are everywhere on surfaces that we eat and work on. Certain studies have even found there to be as much as 2.7 million bacteria cells per square inch on common surfaces in schools, such as desks and keyboards (Millions, 2012). Obviously, this is a problem that should not be left unattended, and there are many ways of sanitizing these surfaces that are proven to work. Tools such as antibacterial wipes, sprays, and liquid cleaning formulas are all options that should be utilized. But which one works the best? We would like to know which method is most effective so that we can prevent ourselves and other from getting sick by making surfaces we touch more sterile.

We plan to use different cleaning methods (wet wipes, antibacterial spray, and liquid spray paired with cloth) on different parts of a smooth surface (a desk or countertop), then take samples of the bacteria from each section and grow the bacteria in petri dishes to find which method works the best.

“ Antibacterial products have never been so popular” (Scientific, 2012). Although all of sanitizing methods are used for the same purpose, many of their germ-fighting ingredients are different. The industry-leading antibacterial company, Clorox®, discloses complete lists of all the ingredients in their products. So, we picked the most popular antibacterial wipe, spray, and formula to compare ingredients. The ingredients that are not used for antibacterial purposes have been left out of the comparisons. Formula 409, a liquid that is to be sprayed on a surface and wiped away to sanitize it, contains the ingredients Cocamidopropylamine Oxide, a “cleaning agent”, Propoxypropanol, a “grease remover and solvent, and Alkyl C12-16 Dimethylbenzyl Ammonium Chloride, an “antimicrobial (Formula, 2012). The Clorox Disinfecting Wipes contain Isopropanol, which has “antimicrobial properties", Propoxypropanol, Potassium Citrate, which “helps remove stains and scum", and Alkyl C12-18 Dimethyl Benzyl Ammonium Chloride and Alkyl C12-14 Dimethyl Ethylbenzyl Ammonium Chloride for their “antimicrobial properties” (Clorox #2, 2012). The Disinfecting Spray contains Alkyl C12-16 Dimethylbenzyl Ammonium Chloride, Quaternium-24, Didecyldimonium Chloride, and Dimethyldioctylammonium Chloride, all of which are used for “antimicrobial purposes” (Clorox #1, 2012). Through much research, we have decided that we think the Formula 409 (the liquid spray paired with a paper towel to wipe it off) will work best. One study at the Welsh School of Pharmacy at Cardiff University even goes as far as saying “Anti-bacterial wipes can spread more than clean” if they are used more than once per wipe (Study, 2012). We think that the formula 409 will work better than the Antibacterial Spray through the thought that physically wiping away the germs will be better than leave all of the work to chemicals.

Overall, the different disinfecting products have different ingredients and ways of application, and by examining these, we think that the Formula 409 with work the best.


 * Hypothesis: ** We believe petri dishes containing the samples from the sections of the counter which were cleaned by the method of using a liquid formula with a paper towel will have the least bacteria in them.

-Agar Powder -Distilled Water -Stirring Rod -Heat resistant Gloves -A Microwave -Petri Dishes -Formula 409 (liquid antibacterial spray bottle) -Botanical Equivalent of Formula 409 Spray -Paper Towel -Clorox Antibacterial Wipes -Botanical Antibacterial Wipes -Antibacterial Aerosol Spray -Wal-Mart Brand Antibacterial Aerosol Spray -Smooth Surface (Table, desk, or countertop) -Sterile Swabs -Tape -Cardboard -Wax pencil
 * Materials: **

First, we isolated a test area. For this, we found a low-traffic area (a countertop in the corner of the classroom), wiped it with a clean, wet rag so that the bacteria that were already on the countertop could be spread evenly, and taped it off into 8 equal-area parts and built cardboard barriers to separate the parts of the countertop. This was to isolate the testing so that each cleaning product only affected the area it was intended to. We then needed to make sure that the entire surface of our testing area had equal amounts of bacteria to make the test more accurate. For this, we took a wet rag and wiped it across every desk in the classroom, then wiped it across each one of our 8 quadrants, in the same pattern of wiping, so that all of our quadrants had the same types and amount of bacteria. We then let the countertop dry, and swabbed each quadrant, in the same pattern covering the entire quadrant, and then smeared each Q-tip onto the halves of the labeled petri dishes that corresponded with each quadrant. We then put each petri dish in optimal growing conditions as our “before” group. After that, we cleaned each quadrant with the designated cleaning products, (leaving two randomly selected quadrants as controls, and applying no cleaning product to them) using the products as their directions instructed. We cleaned Quadrant 1 by spraying the liquid Formula 409 on it, applying an equal coat, and then wiping the surface dry with a brand new, sterile paper towel. Quadrant 2 was cleaned by using a new wet Clorox wet wipe, and wiping all around the quadrant with equal pressure until the entire surface has been cleaned, the surface. Quadrant 3 was a control. Quadrant 4 was then cleaned by spraying the Wal-Mart brand antibacterial aerosol spray over the entire surface, and then leaving the surface alone. Quadrant 5 was cleaned using a new, botanical wet wipe, using the same method as described was used with the Clorox one. Quadrant 6 was sprayed with the Clorox brand antibacterial spray, again using the same method as was used with the Wal-Mart brand. Quadrant 7 was another control, having nothing done to it. Finally, quadrant 8 was cleaned with the botanical equivalent to the Formula 409, once again using the same method as described earlier. We then left all the quadrants alone for five minutes to allow all of the cleaning liquids to evaporate and dry. This was so that when we took bacteria samples with a Q-tip, none of the cleaning product will be directly taken into the petri dish. After the five minutes have passed, we again swabbed each quadrant with a Q-tip, using the same pattern that covered the entire quadrant, and then spread the Q-tip onto the halves of the labeled petri dishes that corresponded with each quadrant. All of the petri dishes were placed in a dark, room temperature area and left alone for one week. When one week has passed, we collected all of the petri dishes and collected data from them. For this, we outlined three 1x1cm squares on each petri dish with a wax pencil. We counted the number of colonies in each square, and then calculated the average of the numbers by adding them together and dividing them by three. We then took the diameter of three colonies from each 1x1cm square, and again found the average of the diameters by adding the numbers together and dividing by nine. Once we had all of the data collected, we calculated the average percent of surface area that the bacteria took up in each square (we chose this method because the size of the colonies of bacteria varied for each petri dish, and we thought that a percent surface area average would be better than a count of colonies). To calculate the average surface area, we used this formula: [(Average diameter of colonies ÷ 2)² times π] times the average number of colonies. This was derived from the area of a circle formula, since all of the colonies were circles. is the area for the formula for the area of circles, so we imputed our data into it by dividing our average diameter by two to find //r//, the radius, and then squared it and multiplied it by π to find the average area of each colony. Once we had the average area, we multiplied it by the average number of colonies, and that was our average surface area, in cm², that the colonies covered in each 1x1cm outlined square on our petri dishes. The results are as follows.
 * Procedure: ** Before we started testing our experiment, we created petri dishes. We took 9.2 grams of agar powder, and mixed it will 400mL of distilled water in a sterile beaker. We then microwaved the mixture for one minute and thirty seconds, until it bubbled. We immediately removed the beaker with heat-resistant gloves, and poured equal amounts of liquid into sixteen empty petri dishes, opening the lid right before pouring and closing it right after. We then let them cool for thirty minutes, and then labeled the bottom of them all with a wax pencil. We divided each petri dish into halves, labeling one side the control, and one side with the quadrant number it would grow bacteria from, and wrote whether it would be the “before” cleaning, or the “after” cleaning sample. When this was completed, we started our procedure.


 * Data: **





Next we examined the results of the “after” cleaning group. As you can see above, the two aerosol spray quadrants had the highest percentages, other than the control groups. The next highest other than the aerosol sprays and the controls was the Clorox wet wipe, which was a good sign for supporting our hypothesis. We then looked at the average percentages of the cleaning methods, which was the most conclusive and easiest to read out of our three charts or graphs. This showed that the Control group had the most bacteria at around 40% of surface coverage (which was just about the average of all of the “before” quadrants), then the aerosol sprays at 27%, then the wet wipes at 16%, and then finally, the most effective of our cleaning methods, the liquid formulas with an average bacteria surface coverage of 10%. We believe these results to be the ways they are for one reason in particular, the cleaning methods themselves. Since all of the products had comparable ingredients, we believe that the aerosol spray was the least effective due to the fact that nothing was actually being physically wiped away from the surface, meaning that all bacteria that weren’t killed by the product were in the clear. Next, we think that the wet wipes were less effective than the liquid formula because not as much of the ingredients themselves were being exposed to the bacteria. When the wet wipe is ran over the surface of an object, only a very small amount of moisture is transferred to the surface. Whereas when the liquid formula is sprayed onto a surface, the surface is practically flooded with bacteria-killing ingredients, which is why we think this method was the most effective.
 * Analysis: ** Upon first review of the collected data, we noticed that the “before” group of bacteria samples were all within about ten percent of each other. This was a positive sign, for it meant that our surface was relatively evenly covered with bacteria when we started. This also meant that our methods of putting bacteria on the surface of the counter were successful.


 * Conclusion: ** Our hypothesis of “We believe petri dishes containing the samples from the sections of the counter which were cleaned by the method of using a liquid formula with a paper towel will have the least bacteria in them,” was mostly supported through our experiment, because the average percent of surface area covered by bacteria from the petri dishes that were exposed to the surfaces cleaned by the liquid formula and a paper towel was the lowest out of the three methods. Although, out of the 8 quadrants, the quadrants that grew bacteria from the surfaces cleaned by the liquid formula were #1 and #3 lowest, not #1 and #2, so this meant that the method was not a clear winner, but more of an average winner.


 * Limitations: ** Although our results were conclusive, they were not completely solid. Since there was a 10% surface area range in our “before” group, we should look at the “after” data, with a give-or-take-5% view, making our results a little less solid. This range could be due to many factors. The bacteria in the air, imperfections in the agar, and not completely even spreading of bacteria on the counter before we tested could all be possibilities. To fix these things and make our experiment more airtight, we could do the following:

-Test in an environment where this in absolutely no bacteria in the air.

-Make our agar all identical by making it in a sterile environment.

-And make sure that the bacteria on all of the surfaces are evenly spread and identical by using more exact techniques of applying bacteria to the surface.

Our new hypothesis would be:

** Works Cited **

"Clorox Disinfecting Spray." //The Clorox Company//. N.p., n.d. Web. 27 Nov. 2012. .

"Clorox Disinfecting Wipes." //The Clorox Company//. N.p., n.d. Web. 27 Nov. 2012. <http://www.thecloroxcompany.com/products/ingredients-inside/en-us/cloroxcommercialsolutions/cloroxcommercialsolutionscloroxdisinfectingwipesfreshscent/>.

"Formula 409 Antibacterial All-Purpose Cleaner." //The Clorox Company//. N.p., n.d. Web. 27 Nov. 2012. <http://www.thecloroxcompany.com/products/ingredients-inside/en-us/formula409/formula409antibacterialallpurposekitchencleanerlemonfreshscent/>.

"Millions of Germs and Bacteria Await Kids at School." //Food Poison Journal//. N.p., n.d. Web. 27 Nov. 2012. <http://www.foodpoisonjournal.com/food-poisoning-watch/millions-of-germs-and-bacteria-await-kids-at-school/>.

"Scientific American Research." N.p., n.d. Web. 27 Nov. 2012. <http://thisbluemarble.com/archive/index.php/t-17744-p-2.html>.

<span style="font-family: Calibri,sans-serif; font-size: 10pt;">"Study By Welsh School of Pharmacy at Cardiff University." N.p., n.d. Web. 27 Nov. 2012. <www.cardiff.ac.uk/news/resource/4650.17404.file.eng.doc>.