How germy are household items?

I don't want anyone getting the wrong idea and thinking that my house is squeaky clean. Usually only my toilets, food preparation surfaces, and hand towels are super clean. We have a big, hairy, drooly dog and lots of kids running in and out. The rest of my house is pretty dirty. I do have a strict hand washing policy. Everyone including adults and neighbor kids have to wash hands when they come in my house from anywhere. I decided to swab some household items to see how much bacteria there was and if anything was germ free. I was surprised that there are some virtually germ-free items! However, not every kind of bacteria can grow on these agar plates and viruses can't grow on these plates. So, just because a plate looks clean, doesn't necessarily mean that no germs whatsoever were present.

kitchen sink


A LOT of bacteria grew. 


Then I swabbed the sink 5 minutes after I sprayed the heck out of it with my 3% hydrogen peroxide. No bacteria grew! 



As you know, I spray my toilets down with 3% hydrogen peroxide at least once a day. I took a swab of the toilet seat a few hours after the last time I cleaned it. 


No bacteria grew! These results are most likely only true for MY toilet seats and anyone else who cleans them like I do. Most people's toilet seats will have LOTS of germs. 


Here is a swab of a friend's toilet. This is a "normal" toilet that I see at most people's houses. 

Even though the toilet didn't look too bad, it was full of germs! Disinfect your toilets, people! Every Single Day! I like using 3% hydrogen peroxide to disinfect them. 

Kitchen Floor

Here is a swab of my kitchen floor that I hadn't washed for at least 2 weeks: 



Here is a swab of the bottom of my son's shoe after school:


Yuck. We really should always remember to take shoes off.


Door knob

Here is a swab of the highly used door knob leading out to the garage that I hadn't sanitized for at least a month: 


It is surprisingly clean. 



How much bacteria is in a dollar bill? 




How much bacteria are on coins? 


Quarters are surprisingly clean. However, I thought it was because silver is known to have anti-microbial properties. However, I've also heard that quarters don't actually contain silver anymore so I'm not sure. 


How much bacteria is on pennies? 


Pennies are surprisingly clean, too. Copper is also known to have anti-microbial properties. I guess when you find a penny, you CAN pick it up. 


Here is a repeat of the coin experiment using different pennies and quarters. 



I bought a new package of underwear from Walmart. (Yes, those are my underwear, much to my husband's dismay.)

I put 1mL of sterile water onto one pair. 

Then I dabbed that pair of underwear onto an agar plate. 

Nothing grew. Those new underwear were virtually free of bacteria. (Unless there was bacteria present that won't grow on this type of agar plate.)

Kleenex Hand Towels

I also tested some disposable Kleenex Hand Towels

I put 1mL of sterile water onto the hand towel and dabbed it onto the agar plate. 

Nothing grew.

Paper Towel

I also tested some Bounty Paper Towel. 

Nothing grew. 

So, this means that there are some clean things in the world. 

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.