Is it better to wash underwear by hand or by machine?

I believe that all the masters who come in have

Same problem:

Washing underwear by hand: Trouble!

Washing in a washing machine: too dirty!

Underwear, which is exposed to shit, urine and fart every day, can be seen with the toes that it is not very clean...

How dirty are they? You can refer to our previous series of studies on underwear:

*《Why do underwear turn yellow after wearing for a while? 》 (Reply "underwear" to Dr. Curious's WeChat account to view this content)

Underwear is a close-fitting item, and its cleanliness is directly related to the health of the buttocks, so it is imperative to study the best way to clean underwear!

In this study, in order to ensure the reliability of the results, we did not just talk about theory, but used experimental data to speak directly!

This is a costly and time-consuming project!

This is a project that embodies the spirit of dedication!

This experiment is divided into three steps:

The 9 volunteers were divided into two groups: hand washing group (5 people) and machine washing group (4 people).

In order to let everyone understand the most real usage in life, they are allowed to buy the underwear themselves and wash it at home.

Two groups of volunteers were provided with underwear to be used in three stages:

After each stage, the volunteers were asked to put their underwear into a sterile bag with clean hands, mark them with their corresponding numbers, and send them to the laboratory for testing.

Detect the total number and type of colonies in underwear:

According to the test method of GB 15979-2002 "Hygiene Standards for Disposable Hygiene Products", if you want to know whether your underwear is clean and harmful to your health, you can mainly test 6 microbial indicators:

Among them, Pseudomonas aeruginosa, Staphylococcus aureus and hemolytic Streptococcus are pathogenic pyogenic bacteria.

In order to determine the degree of microbial contamination and sanitary quality of the samples, we also evaluated the total number of colonies.

We will follow the above three steps to test the cleanliness of "hand-washed underwear" and "machine-washed underwear" respectively, and use the total amount of microorganisms and the presence of pathogenic bacteria as comparison indicators.

Although they bought and washed their underwear themselves, we still carefully recorded their washing habits and frequency:

After inspection, the number of bacteria detected at each stage is as follows:

In order to see the changes more intuitively, we made a line graph of the underwear hygiene of all volunteers.

It is obvious that the hygiene of underwear deteriorates sharply with the number of times it is worn and washed. Even new underwear has been detected with a lot of microorganisms.

And according to the standard SN/T 3335-2012 "Specifications for Microbiological Inspection of Imported and Exported Textiles":

Our actual test results show that the total fungal colony counts of almost all volunteers in the second stage exceeded the standard limit of 100 cfu/g.

The underwear of the second volunteer was found to have a total fungal colony count of 1800 cfu/g.

According to her underwear washing habits, it was found that she rinsed and washed her underwear less frequently each time, and the time between taking off and washing was longer.

It can be seen that these two are not good habits, gentlemen should take them as a warning.

After looking at hand washing, let’s take a look at washing underwear in a washing machine. What will the hygiene conditions be like?

Following the same record keeping method as hand-washing underwear, we tracked and recorded the underwear washing of the four volunteers:

To clarify: the washing machine we used in this experiment is an "ordinary household washing machine" without an automatic drying function, and no disinfectant is added during the cleaning process.

The final data... I thought that the bacteria content of hand-washed underwear was already high, but when I saw machine-washed underwear... it was really unexpected:

In the first stage, when the underwear is still new, after washing in the washing machine, the total number of bacterial colonies and fungal colonies detected is very high. (Some even exceed the limit)

What is most noteworthy is that all the underwear in the machine wash group were found to contain "E. coli" without exception.

Escherichia coli is a pathogenic bacterium that can increase the risk of urinary tract infection under certain conditions and can also cause gastroenteritis. And because of different physiological structures, women are at a higher risk of urinary tract infection than men.

Through the above values, the results are obvious. If you use an ordinary washing machine at home and haven't washed for a long time, then:

Hand washing is cleaner than washing in a washing machine!

So here comes the question

Research by the National Center for Disease Control and Prevention clearly shows that civilian washing machines are seriously contaminated by microorganisms, and improper use and maintenance of washing machines will be detrimental to health.

If you have ever disassembled your own washing machine, you will know how terrible the situation inside is.

So the reason why you can't wash your underwear in a washing machine is because the washing machine is too dirty. Here are some suggestions for you:

If you can't satisfy me, then just wash it by hand~ Don't think about being lazy~

Maybe I thought there were too many words above and didn’t have time to read them, so I’ll give you a few conclusions:

But there is a more convenient way, Koko, find someone who is willing to help you wash your underwear~

Addendum 1:

The experimental data for this study are all provided by "Dad Review". If you want to see more professional reviews, you can search and follow "Dad Review"~

Addendum 2:

Because of the sample size (not so many people are willing to donate their underwear), the above data and results can only be used as a reference~

One minute with the doctor, the postures are constantly improving

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