Cleaning Product Experiments 1


Do White Vinegar, Isopropanol, Hydrogen Peroxide, Method All-Purpose Cleaner, Thieves Spray, and Zylast Hand Sanitizer kill germs?

Answer: 3% Hydrogen Peroxide and Zylast are great!


To test cleaning products, I used masking tape to section off squares on my kitchen countertop and labeled them according to what I would be testing. I made sure that my countertop was very clean to start with, of course. 



Next I made germy water. To do this I mixed a small scoop of mud from our back yard into purified water. Then I poured the muddy water through a paper towel to filter out the chunks. I was left with very dirty water which contains lots of bacteria. For some experiments, I also scraped bacteria off of an already grown agar plate from a previous experiment and mixed those germs in. This way my "germ water" had lots of bacteria in it. 



I put 1mL of germ water onto each square with the exception of the "clean" control square using these 1mL syringes



I rubbed the germ water around the square with my gloved finger. Then I let the squares dry completely which took 2-3 hours. 


Once the squares were dry, I put .5mL of each cleaning product onto its respective square. 


I rubbed the cleaning product around to completely cover the square using a clean gloved finger. I went over the square a few times to make sure that the cleaning product completely covered it. Then I set a timer and let the cleaning product sit on its square for 5 minutes 


After the allotted time, I used a sterile swab to swab the square. Most squares were still wet after 5 minutes. However, if a square was dry, I dipped the swab in sterile water before I rubbed the square. I rubbed all over the square but I did not touch the tape (just in case the tape held onto bacteria and interfered with the experiment). 


Then I scribbled all over an agar plate with the swab. 


If you want to do these experiments yourself, I used these agar plates available on amazon. They come with the sterile swabs.


The plates were incubated for 24 hours in my homemade incubator consisting of a plastic box and a heat lamp. The temperature was about 90 degrees F. In case you are repeating this, the plates need to be put into the incubator upside down. (That means that the agar is on top so condensation does not settle on the bacteria colonies.)  Any bacteria present on the plate will grow and multiply. After about 24 hours you can see colonies (or piles) of bacteria on the plates. It is important to remember that viruses do not grow on these plates. Just bacteria and some fungus. Also all types of bacteria do not grow on these plates. So, a clean looking plate does not necessarily mean that there were no microorganisms present. It just means that nothing that could grow on the agar plate was present. However, this is still a very valuable information for comparing different cleaning products. 




RESULTS

White Vinegar, Isopropanol, Hydrogen Peroxide, Method All-Purpose Cleaner, Thieves Spray, Lysol Disinfectant Spray, and Zylast Hand Sanitizer

In the following experiments, I tested pure white vinegar, Lysol Disinfectant Spray, 70% isopropanol, 91% isopropanol, 3% Hydrogen Peroxide (H2O2), Method All Purpose Natural Surface CleanerThieves Spray, and Zylast Antiseptic hand sanitizer. (Zylast Antiseptic is one of the few hand sanitizers that I recommend for killing norovirus. It can be purchased at http://www.zylastdirect.com/catalog.php and using the coupon code "StopNorovirus" will get you 10% off your order. Zylast is also available on amazon but you can't use that coupon code on amazon.)  I put 1mL of dirty germ water on each square. In the first experiment dated 5-3-2015, the germ water did not have additional bacteria added. The experiment dated 5-5-2015 DID have additional bacteria added. I used .5mL of each cleaning product. To get .5mL of the Lysol spray, I sprayed it into a plastic cup and then got .5mL in a syringe. 


As you can see, only the 3% hydrogen peroxide and the Zylast hand sanitizer seemed to do a great job. The Method All Purpose Natural Surface Cleaner wins the award for my favorite smelling cleaning product. I am stunned and saddened by the Lysol Disinfectant spray results. Since the 5-3-2015 experiment did not have extra bacteria added, it is essentially the same as someone tracking dirty water from outside onto your floor and you spraying it with Lysol. 

I was in such shock about the Lysol spray results that I repeated the experiment without DIRT. I thought maybe the Lysol and the alcohol just couldn't penetrate dirt. So, I scrapped bacteria from the previous days dirty control plate and mixed it up in water. I put 1mL of that "clean" germ water onto each square on my countertop and did the experiment again. 




I was so surprised that I got about the same results. The Method All Purpose Natural Surface Cleaner and the Thieves spray seemed to do a bit better this time. The 3% hydrogen peroxide and the Zylast hand sanitizer really do an impressive job killing bacteria compared to the rest. However, please remember that most of these cleaning products say on the bottle that they can only be used on "pre-cleaned" surfaces. So, I guess I shouldn't be surprised that they don't do much in my experiments. 


3% hydrogen peroxide can be purchased in the bandage aisle in most grocery stores. It can be difficult to find the spray bottles, though. Hydrogen peroxide is unstable and needs to be kept in its own brown bottle. The spray bottles are available on amazon if you can't find them in a store. Zylast Antiseptic is one of the few hand sanitizers that I recommend for killing norovirus. It can be purchased at http://www.zylastdirect.com/catalog.php and using the coupon code "StopNorovirus" will get you 10% off your order. If you want more information about how I clean with hydrogen peroxide, please read the bottom of this page. It is also important to remember that this regular 3% hydrogen peroxide may not kill the dreaded norovirus. So, I recommend using a solution of 10% chlorine bleach or the Clorox Hydrogen Peroxide Spray if anyone in your house has a stomach bug. 

What about my kitchen sink? 

Just because a cleaner doesn't appear to do much in my experiments, doesn't mean that they don't do what the label says. Most of them say that they can only be used on already clean surfaces. Some of my experiments have so much bacteria that it might not be a true reflection of what is going on in your house. So, throughout this page I'll also be testing cleaners on my kitchen sink and my neighbor's kitchen sinks. Here I tested pure white vinegar and hydrogen peroxide on my kitchen sink. I have a 2 sided stainless steel sink. First, I rinse the sink really well to make sure it looks clean. Then I swabbed the sink and rubbed the swab on an agar plate to see how much bacteria was in the sink. Then I sprayed 30 sprays of 3% hydrogen peroxide all over one side and let it sit for 5 minutes. I did not wipe at all. Then I swabbed that side. Then I sprayed 30 sprays of pure white vinegar all around on the other side and let that sit for 5 minutes. I swabbed that side and the plates were incubated overnight. 





As you can see, the pure white vinegar does appear to kill some bacteria. It just isn't as strong as 3% hydrogen peroxide.  The pure white vinegar does seem to kill more bacteria in my sink experiments than the On Guard or Thieves cleaner does (which you will see if you keep reading). I'm still going to use 3% hydrogen peroxide to spray my sinks. There is even a little travel size bottle of 3% hydrogen peroxide available that you can refill. I've tested this one and it is great.



If you would like to suggest an experiment, please post on my facebook page. I also really need to earn money from this website in order to keep doing experiments (agar plates, essential oils, and cleaning products are expensive). If you want to contribute, please use my Amazon affiliate links. Just click on any of my links that go to amazon, and buy whatever you want. You don't have to buy what I recommend or even the product that the link goes to. Here is a link. I'll get a small percentage of the sale and use the money to buy experiment supplies. Thank you.



--Annie Pryor, Ph.D.