Zylast Hand Sanitizer Testing

After testing so many hand sanitizers, Zylast is one of my favorites. Not only does it do well on dirty hands in my experiments, but the company has also tested it and it kills the norovirus surrogate. I see no sense using a hand sanitizer if it isn't going to kill the dreaded stomach bugs. Zylast is a alcohol based hand sanitizer that also contains other germ-killing ingredients. Zylast is not available on Amazon. You can also buy it on their website www.zylastdirect.com. Use the coupon code StopNorovirus to get 10% off your order. 

Zylast® antiseptic testing

First, Katie pressed her "dirty" right hand onto an agar plate and rubbed it around. Then, I applied a small amount of Zylast to her left hand (size of a dime). I rubbed it in and let it dry for 2 minutes. Then she rubbed her left hand onto another clean agar plate. I let the plates incubate overnight. As you can see, the Zylast did a fabulous job killing the germs!

Does Zylast work on dirty hands?

I repeated this experiment but we started with extra dirty hands. Katie rubbed her hands in actual dirt. As you can see, the Zylast still did a great job even in the presence of real dirt! 

Does Zylast work for 6 hours?

Next I wanted to see if Zylast continued to work for 6 hours like they say. For this experiment, I had Jon and Katie wash and dry their hands. Then I put Zylast on one of their hands. Then I let them go and play for 2 hours. They were not allowed to go outside or wash their hands. Jon went to Karate class. After 2 hours, they held their hands up in the air for 3 minutes to allow time for any recently touched germs to die. Then they pressed each hand into an agar plate. The plates were incubated overnight. Unfortunately, there was no big difference in the amount of bacteria on their hands. I repeated this 2 hour experiment many more times and the results were always the same. 

Next I tried to see if the Zylast was still working after 30 minutes. Jon washed and dried his hands. Then I put Zylast on his left hand. He let it dry and then went off to play inside. He was not allowed to touch any actual dirt, but I had him crawl on the floor and touch some lettuce leaves to get some germs. After 30 minutes, he held his hands up in the air for 3 minutes to give the Zylast time to work its magic on any recently touched germs. Then he pressed both hands onto an agar plate. The plates were incubated overnight. There was no difference in the amount of bacteria. Zylast antiseptic is still my favorite though because it kills the norovirus surrogate and works on dirty hands. 


Zylast lotion has NOT been tested for its ability to kill norovirus. However, I decided to test its "immediate kill" ability anyway. For this experiment, I had Jon and Katie go outside to play for a few hours. When they came inside, Katie's hands were FILTHY with actual dirt. Jon's hands still looked clean (so I didn't take a picture of his). 

I had them both rub their dirty right hand onto a clean agar plate. Then I wore clean gloves and rubbed a dime sized amount of Zylast LOTION onto their left hand. The Zylast lotion actually removed most of the dirt on Katie's hand and her hand looked MUCH cleaner. The kids held their Zylast hand up in the air for 1 minute to let it dry. Then they rubbed their Zylast hand onto another clean agar plate. The plates were incubated overnight. 

As you can see, the Zylast lotion did a good job killing bacteria, even on filthy hands. It appears that the Zylast antiseptic did better job killing bacteria on dirty hands. However, Katie's hands were MUCH dirtier in this experiment with the lotion than they were in the experiment with the Zylast antiseptic. So, I really can't say which one works better at this point. I need to repeat it more.

As you can see, I have not been able to show that Zylast continues to kill germs after it is applied. I could not show that Qore24 continues to work, either, or any hand sanitizer that claims to continue to work. Perhaps they really do keep working but for some reason these experiments do not show it. I have no idea why that would be. All I know for sure is that just because you have applied Zylast or Qore 24, your hands are NOT germ-free. If you have the opportunity to wash your hands before eating or reapplying hand sanitizer at that time, I would do so. They are both great at killing germs immediately upon application, though. Zylast claims to kill norovirus and Qore 24 does not.

What works better Zylast Antiseptic or Purell Advanced? 

My previous experiments have showed that hand sanitizers containing primarily alcohol don't work very well on dirty hands. The alcohol doesn't penetrate the dirt very well. Zylast (76% ethyl alcohol) has done a great job on dirty hands most likely because of that extra ingredient, benzethonium chloride. But how does it compare to Purell Advanced which contains 70% ethanol? I did this experiment on the countertop instead of on hands. I divided the countertop into 4 squares using masking tape. 

Then I made "germ water" using dirt from outside and some bacteria from an agar plate that I rubbed my fingers and some spinach leaves on the day before. I put 1.25 milliliters of "germ water" on to each square and spread it around to completely cover the square. I let the squares dry for about 2 hours. 

When the squares were dry, I put 1/4 teaspoon of Zylast on the Zylast square and 1/4 teaspoon of Purell Advanced on its square. I also put 1/4 teaspoon of water on the dirty control square. I spread the hand sanitizers and water around to completely cover the squares. I let them sit for 1 minute and then used sterile swabs to collect samples from each square. I rubbed the swabs onto agar plates and let them grow overnight in my warm incubator (about 98 degrees F). 

As you can see, the Zylast did much better than the Purell Advanced on bacteria. (Remember, that I can't do any tests for viruses.)  I repeated this experiment twice and got the same results both times. So, Zylast is still my choice for hand sanitizers because it works best on dirty soiled hands AND has been shown to kill norovirus. If you want to order Zylast antiseptic, go to http://www.zylastdirect.com/catalog.php and use coupon code "StopNorovirus" to receive 10% off your order. 

Ava Anderson Non-Toxic Hand Sanitizer vs Zylast

Ava Anderson went out of business but I did test the hand sanitizer before that happened. It smells like lemons and did not sting hands. To do these experiments, I used my children's hands when they got home from school. First they rubbed their dirty thumbs on one agar plate. Then I put .5mL of the Ava hand sanitizer on their left fingers. That amount was plenty to soak their fingers, and I rubbed it in thoroughly for about 20 seconds. Then I had them hold their hand up in the air for 1 minute while the hand sanitizer worked. After the minute was up, the kids rubbed their fingers all over an agar plate. Then I put .5mL of Zylast onto their right fingers and rubbed it in. After 1 minute, the children rubbed those fingers on an agar plate. The plates were incubated for 24 hours. I repeated this experiment several times on different days. I can't put all the results up because this page is already WAY too big. The amount of bacteria on the "dirty thumbs" controls varied greatly. I can't tell if this bacteria is the good bacteria naturally found in our skin or bad bacteria picked up at school. It is probably a mixture of both. 

My little Michael also wanted to help do hand sanitizer experiments. He is too little to understand how to rub just his dirty thumbs on the plate. However, he could handle rubbing one hand on a plate. So, I tested each hand sanitizer on him on different days after he had been playing outside for hours. 

As you can see from the results of my experiments, the Ava hand sanitizer doesn't seem to produce a significant decrease in the amount of bacteria. Maybe it kills some bacteria, but it is just not a HUGE difference like the Zylast. The Ava Non-toxic Hand Sanitizer does not claim to kill a certain percentage of germs so the results aren't that surprising. Some natural hand sanitizers claim to only kill bad bacteria and not good bacteria. I don't know how they accomplish that (and I find it hard to believe) but perhaps that is what is going on here.