Laundry Product Experiments

You might not want to know this because ignorance is bliss. However, knowledge is power, and this is really useful information. I recently got an email from a young mother suffering from the terrible bacterial infection, clostridium difficile (c.diff). She asked me how she could protect her family and not spread the bacteria. Specifically, she wondered if the bacteria and spores were killed in the washer and dryer. I did not know the answer. I thought that surely most germs would die in the hot dryer, right? I decided to do some experiments to see. While I can't specifically test for c.diff., I can determine how much bacteria there is or isn't in clean laundry. 

About Agar Plates

For these experiments, I am growing bacteria on agar plates. Viruses can not grow on these agar plates. There are also some types of bacteria that won't grow on these agar plate. So, even if a plate looks clean, that does not mean that absolutely no microorganisms were present. However, the washing method that generates a clean looking plate most likely has less microorganisms total present than a washing method that generates a plate with lots of bacteria. In case you have never looked at an agar plate before, the white and yellow dots are colonies (or piles) of millions of bacteria. 

Does the dryer kill germs?

I have always assumed that a half hour in a hot dryer would kill most germs. I've been known to throw an article of clothing in the dryer that I didn't want to wash just to kill germs. However, I knew I needed to really test it to be sure that most germs die in the dryer.  First I drew circles on dishcloths. 

Then I put 1mL of dirty "germ water" on each circle. I made the germ water by mixing a little scoop of dirt from my back yard in water and filtering it through paper towel to remove chunks. 

I pressed one circle from each cloth onto an agar plate. This would be the dirty positive control. I also pressed a clean spot on the cloth that had no germ water onto an agar plate to be the clean negative control. 

Then I put the cloths in my Samsung Dryer on the "Sanitize" setting for 30 minutes. 

After the cloths were done in the dryer, I added 1mL of sterile water to each dirty circle, and pressed those circles onto agar plates. (Bacteria don't transfer well from a cloth onto an agar plate unless the cloths are wet.) The agar plates were incubated for 24 hours in my warm incubator (which is about 90 degrees F). I have a picture of the incubator on a few of my other experimental pages if you want to see it. 

Much to my surprise, there really didn't seem to be a decrease in the amount of bacteria on the plates after the 30 minutes in the dryer. In case you have never looked at agar plates before, the white spots are colonies (or piles) of millions of bacteria. There can also be fungus on the plates. Viruses will not grow on an agar plate so we are not looking at viruses. Also, not every kind of bacteria will grow on these agar plates so there could be bacteria present in any of my experiments that don't show up on the plates. 

There didn't seem to be a decrease in the amount of bacteria after 1 hour in the dryer either. 

I repeated the experiment again using a VERY germy cloth. This time I put it in the dryer for 2 hours, and I did see a significant decrease in the amount of bacteria. 

So, it appears that the dryer does not kill all germs like I had hoped. It can kill the majority of germs, though, IF you have it on a very hot setting. I noticed that my high efficiency dryer doesn't always get that HOT when I only have one or a few items in it. Some of the high efficiency dryers like mine sense how wet a load is and will only use the minimum amount of heat necessary. So, my dryer only gets HOT when there is a normal sized WET load in there. Even if I put it on the "sanitize" setting, it doesn't seem to get that hot if I only have a few things in it. I also attempted to take the temperature of my hot laundry. I opened the dryer door in the middle of the cycle, stuck my meat thermometer in there, and pressed the clothes tightly around it. The hottest that I ever caught my dryer was 160 degrees F. I really would have thought that temperature would have killed more germs than it did. However, if you read my experimental results when I tested the germ-killing power of boiling water which is on the page about Norwex cloths, you won't be surprised that 160 doesn't kill everything. 

How germy is everyone's laundry?

After I discovered that the dryer didn't kill all germs like I had thought and hoped, I wondered if everyone's "clean" laundry was actually full of bacteria. My family, neighbors, and friends were very good sports about me testing their laundry. I went to everyone's house when the dryer was done. Wearing gloves, I selected 2 pieces of laundry from their dryer. I put 1mL of sterile water on each piece of laundry.

Then I dabbed the laundry onto an agar plate. The plates were incubated in my warm incubator for 24-48 hours. 

Neighbor #1 an #2 had older top loader machines (not high efficiency). They both washed these 2 loads on hot with no bleach. #1 used All free and clear detergent.  #2 used Gain. As you can see, the clean laundry has a lot of bacteria. 

My neighbor Patty has a new HE Samsung front loader. Her load was washed on hot with no bleach and is still very germy. She used All Small and Mighty laundry detergent. My neighbor, Bethany, has a front loader and washed her laundry on hot with no bleach (she used vinegar and a Tide Pod). Bethany's laundry had a lot of germs. My laundry (Annie's laundry) and Courtney's laundry were both washed on hot with 1/2 cup chlorine bleach and looked pretty good. I used Tide Free and Clear detergent. Courtney has an older front loader and put the bleach into the dispenser. I have a high efficiency Samsung top loader, and I added the bleach to the wash water for this load in this particular experiment. 

My mother and sister Gina washed their laundry on hot with no bleach. Mom has an old top loader with agitator and used Tide. Gina has a high efficiency Samsung top loader and used original Tide liquid HE. Gina's looks surprisingly good for not using bleach. 

My sister Christy has an older top loader (not HE). She washed this laundry on hot and added the 1/2 cup chlorine bleach directly to the wash water and it was very, very clean. She measured the temperature of her wash water when the tank filled up using her meat thermometer and it was 130 degrees F. She used Sam's club detergent. Her laundry was perfectly clean (to the limits of my detection abilities).

So, at this point I realized that all of our clean laundry is probably full of bacteria unless we used chlorine bleach. Norovirus and C. diff are much harder to kill than ordinary bacteria so those organisms would certainly survive the even the best washing without bleach. Maybe that is why even when we are so careful, a stomach virus still spreads to everyone in the house?  The main problem with chlorine bleach (besides the fact that is isn't healthy for you) is that it can only be used on white loads because it fades everything. Also, adding chlorine bleach is not quite as simple as it sounds. Bleach didn't work in my washer at first. Keep reading. 

Does the washer kill germs if you use chlorine bleach?

The previous experiments that I did where I tested people's clean laundry led me to suspect that laundry would only be germ-free IF you used 1/2 cup of chlorine bleach in each load. However, it is not quite that simple. At first, even adding bleach to my machine did not produce clean laundry. Also, please note that I am using concentrated Clorox Chlorine bleach in my experiments. The directions say use 1/2 cup bleach per load. 

I HATE my Samsung HE top loader! 

I have a high efficiency Samsung top loader, and I am not impressed with it. There is no way to manually increase the volume of water used. I've never felt that it used enough water or agitated the laundry enough. Here is a video of my washing machine "washing" my son's sheets and comforter. It is hard to see because the lid is dark, and I had to shine a flashlight in and hold my phone. As you can see, the laundry is not covered in water and is not agitating at all. Here is the video. So, if you are shopping for a HE top loader, this is probably what you are going to get. I would recommend an HE front loader or an old fashioned agitator top loader that uses more water.

In addition to not using enough water or agitating enough, when I do a "normal" load on HOT, the water temperature in the tank after it fills up is only 90 degrees F. That is not really even warm. I suspect this "high efficiency" machine just refuses to let me "waste" hot water. Yes, we have checked the water coming out of the tap directly into the machine and it is 140 degrees F. In addition, you have to put the chlorine bleach in the bleach dispenser. You cannot easily add the bleach to the water as it fills up because the machine won't fill up until the clothes are in it. Also, 
I have tested my tap water numerous times for bacteria and nothing ever grows on the agar plate. So, my tap water is very clean and is not contributing any bacteria to these experiments.

When I do a hot load on the normal wash setting and put chlorine bleach in the dispenser, these are the results that I get. The bleach hardly does anything! I repeated this in disbelief numerous times. This is how I've been doing my white underwear/sock load for a year! No wonder my husband always has athletes foot! My only explanation is that the bleach did not get enough TIME with the laundry when it was added to the dispenser. 

However, when I add bleach directly to the wash water or put the bleach in the soap dispenser, I get very clean results. I really think that the bleach just needs more time with the laundry and does not get that time when it is added to the dispenser. These options are not ideal, though. When I add the bleach to the soap dispenser, it immediately leaks directly onto the clothes. I've gotten holes in most of my towels because the bleach fell directly on them from the soap dispenser. I can pause the machine after it has filled up and add bleach to the water, but it is too easy to forget to do that. Also, sometimes my machine just refuses to pause, and I can't add the bleach. So, I really, really wish I had a different washing machine. 

When I did a hot load with bleach in my neighbor's old Whirlpool machine, I added the bleach directly to the wash water and got very clean results. I used my Tide Free and Clear detergent for this load. It looks like a few bacteria were picked up from the dryer which wouldn't have been sterile.

I was worried about front loaders. There is no way that you can add bleach directly to the wash water in those. I did a load in both of my neighbor's front loaders using 1/2 cup of bleach in the dispenser, and they both came out very clean. Whew. The front loaders agitate the clothes so much more than a top loader (with no agitator). Maybe that is why they work better. 

Does 3% hydrogen peroxide kill germs in the laundry? 

I wished there was a way to produce laundry with less bacteria without using chlorine bleach. I tried putting 1 full cup of 3% hydrogen peroxide in the wash water of a hot load of laundry. I was not impressed with the results. 3% hydrogen peroxide is fantastic for cleaning as you can see in my cleaning experiments. However, it does not work well when diluted so much in the laundry. 

Does Clorox 2 Color Safe Bleach kill germs in the laundry?

I also tried Clorox 2 color safe bleach to see if that would kill a significant amount of germs. It is primarily hydrogen peroxide so I didn't have high hopes. 

The results don't show any significant germ killing from the Clorox 2, unfortunately. 

Does OxiClean kill germs in the laundry? 

Several people requested that I test OxiClean to see if it would kill germs in the laundry. The OxiClean container does not mention anything about killing germs, though, so I didn't have high hopes. I washed 2 loads of laundry on cold with my normal Tide free and clear detergent and 1/2 cup of OxiClean in each load. To save money on agar plates, I just tested the laundry when it came out of the washer. We all know by this point that the laundry was full of germs going in to the washer. Here are the results after washing with Oxiclean. 

So, the laundry still had a ton of germs after washing with Oxiclean. However, my washer is not the greatest, so I had two of my neighbors wash their laundry with 1/2 cup of the Oxiclean. I blotted their laundry onto the agar plates AFTER the dryer. The dryer does kill a lot of germs so their laundry is not as germy as mine which was blotted onto the agar plate before the dryer. 

I have not detected any significant germ-killing ability from the Oxiclean. It certainly doesn't compare to using chlorine bleach in the wash water. Bummer. 

Does Borax Kill Germs in the laundry?

I did 2 cold loads in my washing machine with 1/2 cup of Borax in addition to the regular Tide Free and Clear. I blotted the laundry onto an agar plate when it came out of the washer. I did not notice any significant bacteria killing ability of the Borax. I also tested Borax in some of my countertop cleaning product experiments and it did not kill any significant amount of germs in those either. So, I won't be relying on Borax (Although, it does seem to be good for killing ants.) Keep reading because I tested Borax one more time in my new washer. 

My new Whirlpool duet front loader washer

Great news! My washer that I hated (Samsung HE top loader) broke, and I got a new one! I looked at every washer in town and had so much trouble deciding what to buy. Should I get an old fashioned top loading Speed Queen that uses lots of water but is relatively small? Or try a HE front loader which would be big enough to fit all of my little Michael's bedding (since he wakes up soaked every morning)? Which would kill germs the best? I wished I could test them all first but I couldn't. Eventually, my husband just went out and bought one without me since I couldn't decide. Luckily, I like it! I got a Whirlpool Duet HE front loader. It has a sanitize cycle and a steam cycle. I've had since December 2015, and I still like it. There could be a better washer out there, I just don't know which one. It does not use much water. Just the normal cycle doesn't use enough water to displace all the pee in my son's pajamas. I have to use the extra heavy soil sanitize cycle with extra rinse for really dirty stuff. 

Tide Free and Clear

My last washer made it nearly impossible to generate clean underwear because adding chlorine bleach to the dispenser did not result in clean laundry for some reason. So, the first thing I tested with my new washer was whether or not I could get the white towel/sock/underwear load bacteria-free by using 1/2 cup chlorine bleach in the dispenser, Tide Free and Clear detergent, and the sanitize cycle (set to normal soil). I also used the extra rinse because I want to make sure all the bleach is removed. The cycle is 1 hour and 45 minutes. I blotted several pieces of laundry from the load onto the agar plate straight out of the washer. I did not dry the laundry before testing it. 

As you can see, I have achieved a clean white load!!!! Of course, I hope you remember that I am only testing for the presence of bacteria on these agar plates. I can't grow viruses at home. There are also some types of bacteria that won't grow on this type of agar plate. So, even if a plate looks clean, that does not mean that absolutely no microorganisms were present. However, the washing method that generates a clean looking plate most likely has less microorganisms total present than a washing method that generates a plate with lots of bacteria. So, I am very happy with these results!

Here is my dirty dish towel load which STUNK they were so dirty. Again, I used the sanitize cycle set on "normal soil", extra rinse, 1/2 cup bleach in the dispenser with Tide Free and Clear detergent. It did great! 

I also tested the dirty dish towel load washed on COLD with 1/2 cup of bleach. It did great, too. So, you can use cold water with chlorine bleach. Cold water helps keep the bleach fumes down to a minimum. 

I still expected the cold load without bleach to have lots of bacteria and it did. This load used Tide Free and Clear detergent. 

Here is a cold load after washing and then after drying. The dryer (which is still my Samsung dryer) does kill some germs. It used Tide Free and Clear detergent. 

Here is a cold load using no detergent at all. 

Here is a cold load using regular Tide detergent. Still plenty of bacteria. 

Even though the cold loads still had a lot of germs, I do think the clothes get visibly much cleaner than my old washer got them. I washed my long white puffy winter coat on delicate (with no bleach) in my new washer and it came out very clean. I washed it last year in my old washer and it didn't look any cleaner at all. When I wash my young son's pajamas that are soaked with pee, I need to use the heavy soil cycle with the extra rinse because they still smell like pee if I just use the normal cycle. Overall, I am quite happy with my Whirlpool Duet HE front loader. I always leave the door open and have had no problems with mold or mildew smell. 

Kirkland Free and Clear Detergent from Costco

I also tested Kirkland Free and clear laundry detergent from Costco and it did not see any amazing bacteria-killing. 


Now that I have a better washer, I wanted to test some more laundry products. I put 1/2 cup Odoban in the bleach dispenser and 1/2 cup Odoban in the fabric softener dispenser for a grand total of 1 cup Odoban in this load. I also used Tide free and Clear. I used the sanitize cycle set at the "normal soil" level. The cycle was 1 hour and 45 minutes. 

As you can see, a lot of germs were killed but there still were a lot left. As I discovered later, the sanitize cycle would work this well with NO detergent so I don't think the ODOban is making any significant contribution. It smells nice, though. OdoBan did not kill a significant amount of bacteria countertop germ experiments either which you can see here


I also wanted to retest Clorox 2 in my new washer. I added 1/2 cup Clorox 2 to the bleach dispenser and 1/2 cup of Tide free and clear. This was a warm load and a normal cycle. The Clorox 2 did not seem to impact the amount of bacteria in my new washer either. 

Thieves laundry detergent

I also tested Thieves laundry detergent in my new HE front loader. It smells wonderful! I put 1 tablespoon of the Thieves detergent into the detergent dispenser. It didn't seem to have much impact on the amount of bacteria. 

3% hydrogen peroxide in my new washer

For this experiment, I washed some beach towels in the sanitize cycle with 1/2 cup hydrogen peroxide instead of chlorine bleach. It was the "normal soil" sanitize cycle, and it did not yield the super clean results that chlorine bleach does. 

Here I tested the dish towel load with 1 full cup of 3% hydrogen peroxide. I poured half in the detergent dispenser and half in the bleach dispenser. I ran the heavy soil sanitize cycle with extra rinse. It did pretty good but it was not as good as chlorine bleach. The sanitize cycle on its own does this well. 

I also tested using 1/2 cup hydrogen peroxide in a normal cold wash cycle. 

I also tested a cold normal load with 1/2 cup 3% hydrogen peroxide in the detergent dispenser, 1/2 cup in the softener dispenser, and 1/2 cup in the bleach dispenser (so 1.5 cups total) and Kirkland detergent on top of the laundry in the machine. It didn't seem to do a great job. 

As great as it is on surfaces, 3% hydrogen peroxide does not seem to do much germ killing in the laundry. It must not work well when diluted.

BORAX in my new washer

I decided to test Borax in my new washer with a soak cycle. I washed these loads on the cold heavy soil cycle with an extra soak cycle. I mixed 1/2 cup borax in 1 cup of water. I poured half in the detergent dispenser and the rest directly on the laundry. I also added the extra rinse so the cycle was 1 hour and 51 minutes.

I recommend NOT relying on Borax for any germ killing. 

Does the sanitize cycle kill bacteria in the laundry? 

My new HE Whirlpool duet front loader has a sanitize cycle that I have used on the "normal soil" setting for several experiments. It finally occurred to me to crank it up to the "heavy soil" setting and see what it can do. For these experiments, I used NO BLEACH and NO DETERGENT. I just wanted to see what the washer itself can do. I used the sanitize cycle set on the "heavy soil" setting with the extra rinse. It was 1 hour and 52 minute cycle. I pressed many pieces of each load of laundry onto an agar plate when they were done in the washer before going into the dryer. 

These results are pretty darn good. The sanitize cycle is not as good as using chlorine bleach but it is probably good enough. They are not always this clean on the sanitize cycle, though. Here is a picture I already posted of a dish towel load done on the sanitize cycle with Kirkland detergent and 1 cup hydrogen peroxide. It is not quite as clean but the dish towel load is my dirtiest, stinkiest, load of all.

Before I had gotten my new washing machine, I tested the sanitize cycle on my neighbor's machine. I did a hot load on the sanitize cycle in my neighbor's machine and did NOT use chlorine bleach but I did use Tide. I also only had the "normal soil" level selected.

As you can see, it seems to do better than a regular cycle but it is still not as clean as using chlorine bleach. This machine might be able to do better if I set it to  "heavy soil" so I'll try to test it again sometime. 

I also tried the "Heavy Duty" cycle on my old Samsung HE top load washing machine without using bleach. It was almost a 2 hour cycle and the machine got very hot. I couldn't test the temperature because the lid locked and it wouldn't pause. I was not impressed with the results. I am very happy with my new Whirlpool Duet HE front loader. 

Crystal Wash

Crystal Wash allows you to do your laundry with NO detergent! You put these 2 balls in your washer that contain special "bio ceramics" that change the pH of the water and allow dirt and bacteria to be removed naturally. The company claims that it is as good as regular detergent, natural, and will save you money. To recharge your crystals, you simply set the balls in the sun for the afternoon. I decided to test crystal wash on some cold loads of laundry in my new front loader. I simply put them in the machine on top of the clothes and ran a normal cold wash cycle. 

After the wash cycle, I blotted several pieces of laundry onto an agar plate. The plates were incubated for 24-48 hours in my warm incubator.

This particular day I had a lot of laundry to do and was able to do 3 different cold loads of laundry. So, you can see how NO DETERGENT, compares with Kirkland detergent (from Costco), and Crystal Wash.

As you can see, there is always a lot of bacteria in cold loads of laundry. The Crystal wash did not seem to do BETTER or WORSE than regular detergent. The company claims that it is as good as laundry detergent and it probably is as far as germs are concerned. The laundry did seem clean after Crystal Wash. So, if you want to try Crystal wash to save money on detergent, go for it. 

Lysol Laundry Sanitizer and Norwex Detergent

Norwex Detergent

Posted 7/7/2017

After many requests, I tested the Norwex detergent. I blotted dirty laundry onto one agar plate, then I washed the laundry with 1 scoop of Norwex detergent (30 mL) on a warm, normal cycle in my HE Whirlpool front loader. When the cycle was finished, I wore clean gloves and carefully blotted several pieces of wet laundry onto another agar plate. The plates were incubated for 24 hours in my warm incubator (about 90 degrees F). Not surprisingly, there is still bacteria in the laundry. 

Here is another load that I did on a hot normal cycle with 1 scoop of Norwex detergent. It looks about the same as every other detergent. Although, if you keep reading my Lysol laundry sanitizer results, there does seem to be something special about the Norwex detergent. 

I really did like using the Norwex detergent, though. It has a very subtle, pleasant, clean smell that I love. I hate detergents that smell strongly of perfume. It seemed to do a great job cleaning the laundry. Everything was soft, and it is free of all kinds of unpleasant chemicals. So, if you like the Norwex detergent, go for it. I have yet to find a detergent that really rids the laundry of germs anyway, so I don't think any are BETTER detergents than Norwex at this point. If you would like to order Norwex detergent, here is a link to the Norwex rep's website who sent me the detergent to test. Keep reading to see how Norwex pairs with the Lysol Laundry Sanitizer. Norwex fans will be happy!

Lysol Laundry Sanitizer

posted 7/7/2017

I was so excited to test the new Lysol Laundry Sanitizer! It does not contain any bleach and claims to kill 99.9% of bacteria. It would be so WONDERFUL to have an alternative to chlorine bleach that really killed germs! I purchased the Lysol Laundry Sanitizer at Walmart. According to the directions on the bottle, you simply add the Lysol Laundry Sanitizer to the fabric softener dispenser in your washing machine. 

In this experiment, I blotted several dirty pieces of dirty laundry onto an agar plate. This is not artificially contaminated laundry. This is my real laundry basket full of dishcloths and dish towels that I used all week. I put two capfuls of the Lysol Laundry sanitizer into the fabric softener dispenser (which overflowed it a little). I also used Kirkland free and clear detergent in the detergent dispenser. Then I washed the laundry on the normal, warm, heavy soil cycle in my Whirlpool HE front loader. The cycle was 1 hour and 15 minutes. After that, I wore clean gloves and carefully blotted several pieces of wet laundry onto a clean agar plate (before they went into the dryer). The plates were incubated for 24 hours. 


There is a decrease in the amount of bacteria on the plates, but is this killing 99.9% of germs? I don't know. I don't think so. All I know for sure is that the results on my agar plates do not even compare to the clean results that I get when laundry is washed with chlorine bleach. Huge Bummer. Just to refresh your memory, here is a load of laundry washed on COLD with a half cup of chlorine bleach. (If I use a hot sanitize cycle, it gets even cleaner.)

I tried again. This time using a hot, heavy soil, normal cycle with 2 cups of Lysol Laundry Sanitizer in the fabric softener dispenser. This was a particularly stinky dish towel load, and it certainly didn't get clean. 

I wasn't ready to give up yet. I tested the Lysol Laundry Sanitizer in my neighbor's old fashioned top loader. I put 2 capfuls of the Lysol Laundry Sanitizer right on top of the laundry. So, it was with the laundry the entire time. I used a high water level, heavy soil, warm cycle. These results look a better. 

In the 2 experiments below, I put 2 capfuls of the Lysol Laundry Sanitizer in the DETERGENT dispenser (not the fabric softener dispenser like the directions say) of MY Whirlpool HE front loader. I washed them on hot, heavy soil, normal cycle. I didn't use detergent. 

There is less bacteria in the laundry after washing with the Lysol Laundry Sanitizer. It seems that the Lysol Laundry Sanitizer works better when it has more TIME with the laundry and possibly in the warmer water (since rinse cycles are usually cold). It still doesn't compare to chlorine bleach. 

I still wasn't ready to quit. This time, I washed the laundry first on a normal, warm cycle with Kirkland free and clear detergent. Then I washed it AGAIN on a hot, normal, heavy soil cycle with 2 capfuls of the Lysol Laundry Sanitizer in the DETERGENT compartment. Now, the laundry is starting to get clean. 

Next, I tested 2 cups of Lysol Laundry Sanitizer in the DETERGENT dispenser of my Whirlpool HE front loader AND 1 scoop of Norwex detergent on top of the laundry. I ran it on a hot, heavy soil, normal cycle. 1 hour and 15 minutes

These results looked amazing! So, I did it again.

These results were not quite as good as the first time but still impressive. I repeated it again with Norwex detergent and the Lysol laundry sanitizer.

These results indicate that the combination of the Norwex detergent and the Lysol laundry sanitizer (when the Lysol laundry sanitizer is in the detergent dispenser) works very well! There may be a synergistic effect happening. 

I repeated this experiment again, but I used Kirkland free and clear detergent instead of the Norwex detergent. I put the Kirkland detergent on top of the laundry and 2 capfuls of the Lysol Laundry Sanitizer in the detergent dispenser. I used a hot, heavy soil, normal cycle. 1 hour and 15 minutes

The results with the Kirkland detergent and the Lysol Laundry sanitizer were not impressive compared to the Norwex detergent with the Lysol laundry sanitizer. 

I also repeated the experiment using a Tide Pod detergent. I put the Tide pod in the washer on top of the laundry and 2 capfuls of the Lysol laundry sanitizer in the detergent dispenser. I used the same cycle that I had been using (hot normal cycle that was 1 hour and 15 minutes). 

The results aren't as impressive, either. It really seems like the Norwex detergent and the Lysol Laundry Sanitizer make a good combination. There may be something special about the Norwex detergent. 


I'm disappointed that the Lysol laundry sanitizer is not nearly as effective at killing bacteria in the laundry as chlorine bleach. I'm not saying that it does not do what they claim (killing 99.9% of bacteria). I'm just saying that it doesn't compare to chlorine bleach in my experiments. I don't personally think it is worth buying and putting in the fabric softener dispenser.  If you are going to use it, I'd put it in the detergent dispenser or directly in with the laundry. (Of course, I could probably get in trouble by telling you not to follow the manufacturers directions for a product.) I'd also use it with the Norwex detergent for now, because that made a very effective combination. (I do not sell Norwex and am not affiliated with the Norwex company. In fact, most Norwex reps don't like me.)

If you have vomit covered laundry that can't be bleached, I would wash it 3 times and add the Lysol Laundry Sanitizer to the last 2 wash cycles in the detergent dispenser. (The Lysol Laundry Sanitizer does not claim to kill any viruses, so we would just be hoping it would help with vomit covered laundry.) The Lysol Laundry Sanitizer has a very strong perfume smell. Your laundry will at least SMELL clean. I am a " free and clear" kind of girl so I don't like the smell.  Now, it is possible that the Lysol Laundry Sanitizer would work better in a different washing machine. I was only able to test it in 2 machines. 


A website viewer sent me a bottle of this Persil Hygiene Disinfectant Rinse . It It is also a laundry additive that goes in the fabric softener dispenser. The bottle has no English in it. So, I just put 1/2 cup into the fabric softener department with no detergent to wash my dish towel load.  I blotted some dirty laundry onto an agar plate, ran the cycle, and then blotted the clean laundry onto another agar plate. The plates were incubated for 24 hours.  I ran it on a normal warm 40 minute cycle.

The results show that there was a decrease in the amount of bacteria in the laundry just using this Persil Hygiene Disinfectant Rinse in the fabric softener dispenser. I need to do more experiments to determine if adding it to the detergent dispenser so it would have more time with the laundry would yield better results. So, check back later for more Persil results. 

PureWash Pro

I have also tested the pureWash Pro laundry system that uses ozone to kill germs. Those results are on a separate page. Click here to see those results

How much bacteria is in the washer and dryer themselves?

I guess it is easy to imagine that if the laundry comes out of the washer full of germs, there are probably a lot of germs in the washer itself. I swabbed the washer after a cold dark load and there was plenty of bacteria. So, when someone has a stomach bug and you wash vomit covered laundry without bleach, there are still very likely to be viruses in the clean laundry AND contaminating the washing machine. 

The dryer walls get so hot that I find it hard to believe that any germs could live in there. I swabbed it and there were just a few colonies. The dryer is generally much cleaner than the washer, though. 

Here I swabbed my new HE Whirlpool Duet front loader washer AFTER the self-clean cycle. I used 1/2 cup chlorine bleach in the dispenser during the self-clean cycle. 

The self-clean cycle worked great, and I'm going to remember to do that once every few weeks and ALWAYS after washing stomach flu laundry. 

Do germs die in clean laundry over time? 

I imagine that some germs will die over time in clean dry fabric. I had my mother and sister mail me some of their laundry and it took 4-5 days to get here. There was still plenty of live bacteria in their laundry. 

I also put some of my clean laundry in a ziplock bag for a full week, and it still had plenty of live bacteria. So, some germs likely die over time but there is still plenty of bacteria alive after a week. 

Is ANYTHING germ-free?

We all know that the world is not a sterile place. There is lots of good and bad bacteria in and around us all the time. I am in no way suggesting that we need to kill all germs. But I did wonder if ANYTHING is really clean and free of bacteria. So, I tested a few things. I bought a new package of underwear from Walmart. 

I put 1mL of sterile water onto one pair. (Because bacteria transfer better to an agar plate when the fabric is wet.)

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.)

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.

I also tested some Bounty Paper Towel. 

Nothing grew. 

Why is germ-free laundry important? 

Most of the time, it is not important to kill every germ in your laundry. We have all been living with bacteria in our clothes our entire lives and most of us are perfectly fine. In fact, we have lots of good bacteria living in our skin all the time. Much of the bacteria in our clothing is probably harmless bacteria from our skin. I am in no way suggesting that we all need to bleach (and ruin) all of our clothes. Nor am I suggesting that we need to kill all the germs in our lives and live in a bubble. Even though we need to accept that our laundry has germs, there are a few occasions where being able to get laundry really clean would be helpful. For example, the bacteria in the cloth that you used to wipe up raw chicken, is unlikely to be good bacteria. Germs in your underwear when you have a stomach bug are going to be bad germs. If someone in your house has a contagious stomach bug and you are washing vomit covered laundry, it would be nice if you could get the germs out of that laundry. Otherwise, the "clean" laundry will still contain the virus and it will spread to other members of the house. Also, if you are having recurrent infections such as vaginal infections, staph infections, or athletes foot, you might want to consider using chlorine bleach in your underwear/sock load and see if it helps get rid of those infections. Alternatively, you can boil your underwear/socks for 10 minutes to kill germs. (See my boiling experiments on this page. They are fascinating because some bacteria survive boiling for 5 minutes.)  Hospitals and nursing home laundry needs to be sterilized or they will have outbreaks of c.diff, staph, and norovirus. (Oh wait, they do have those outbreaks.) The scrubs that hospital works were are usually brightly colored and can't be bleached. I bet even the clean ones are full of nasty germs. I took my daughter to our local Children's Hospital last week for a GI scope. The hospital gown and bed sheet was turquoise so I doubt they were bleached. 

Laundry Tips

I have learned quite a bit about laundry from doing these experiments. 

1. If you want to use chlorine bleach, add 1/2 cup directly to the wash water as the machine is filling up if that is an option. That kills germs better than using the dispenser in some machines (like mine). Adding bleach to the dispenser for front loaders seems to be fine. DO NOT BUY Splashless Bleach. It is not the same and does not kill germs as well. 

2. Chlorine bleach is only good for 3 months after opening, so buy the smallest bottle. 

3. If you are shopping for a new washing machine, don't feel that you have to buy a new expensive high efficiency machine. There is lot to be said about a machine where you can increase the water level yourself and add bleach straight to the wash water. Do you want to be the boss or do you want the machine to make all the decisions? Do not get a HE top loader. 

4. If someone in your house has a stomach bug and you wash their vomit covered laundry without bleach, you need to know that it will most likely still have the germs in it after it is out of the dryer. Your washer and dryer will also likely have the germs in them. So, you can easily spread the sickness to other members of the house from the laundry that you think is clean. Wash the vomit load multiple times and wear gloves when transferring laundry from the washer to the dryer when someone in the house is sick. Run the washer empty with chlorine bleach after washing a vomit load to clean the machine. Also, seriously consider throwing the soiled articles of clothing away or quarantining them for a few weeks after washing. If you have a HE front loader machine with a sanitize cycle, use that. 

5. If you have a stomach virus in your house, consider cleaning up with paper towel or disposable wipes because getting all the virus out of the laundry is difficult. I recommend these Clorox Hydrogen Peroxide Wipes which kill norovirus. 

6. If you cloth diaper and baby has a stomach virus, consider switching to disposable diapers for the time. I don't think you will really ever get the viruses out of those diapers unless you can use chlorine bleach on them. 

7. If you wipe up raw meat with dish cloths, those germs will still probably be in the cloths even after washing on hot in the washer (unless you use bleach). You can boil the cloths for 10 minutes to kill germs if you prefer. See more cloth cleaning experiments including microwaving cloths and boiling cloths on the Norwex page

8. Use whatever detergent you like (or Crystal Wash). I have yet to find a laundry detergent that has any significant effect on the amount of bacteria in the laundry so use whichever one you like that you think gets your laundry the cleanest. I'm still looking for an amazing detergent, until then if you want to kill germs, use a strong sanitize cycle or chlorine bleach. 

9. I have found that putting too much laundry in the machine gives poor results. This is the biggest load size that got properly cleaned in any of the machines that I tested. 

10. High efficiency dryers like mine that "decide" how much heat to use, seem to heat up more when there is a normal sized wet load in there as compared to just a few items. 


An easy way to test your laundry for germs

I wish I could test every single washing machine and every single detergent, but I just can't.  However, you can do a quick experiment with hydrogen peroxide to see how clean your laundry is. I made this YouTube video to show you how. You can repeat my experiments and test your own laundry. Just order these agar plates from Amazon and follow my steps. You don't really NEED an incubator. Just set the plates in a warm room for about 48 hours and see what grows. If you are repeating the experiments, it is important that you set the agar plates UPSIDE down to incubate. That means that the agar is on top and the lid is on the bottom. If you have questions, you can send me an e-mail and I'll talk you through it. phd.annie at This would also be a great Science Fair project for your kid! 

YouTube Video

Subpages (1): PureWash Pro Testing