A reliable N95 disinfection method is finally here: put it in your rice cooker and dry it | Produced by the University of Illinois at Urbana-Champaign

Guo Yipu from Aofei Temple
Quantum Bit Report | Public Account QbitAI

Heat up leftover rice in a rice cooker and it’s edible again;

Heat up the used N95 in the rice cooker and it can be worn again.

For Professors Thanh H. Nguyen and Vishal Verma of the University of Illinois at Urbana-Champaign, how to reuse N95 masks is their most recent concern.

They first put a towel in the rice cooker, making sure it is a dry towel, to prevent the mask from being burned.

Then put the mask on and heat it to 170℃.

At this time, since the mask and towel in the pot are slightly lower in temperature than the pot, the mask is probably in an environment of 100°C.

If your family is large, you can also consider stacking the masks of the whole family, young and old, together and putting them in the pot. The whole family can use the same pot of masks to keep them neat and tidy.

After 50 minutes of heating, a "dry pot mask" is ready.

At this moment, the virus in the mask has become burnt and crispy, and all vital signs are gone.

This cooking process can kill viruses at a rate of up to 99.99%.

It not only kills the virus on the outer surface of the mask, but also ensures the filtering performance of the mask, and it can still fit the face as usual.

It really has all the characteristics of color, fragrance and taste.

The researchers tried it and found that the mask can be heated repeatedly 20 times without affecting its effectiveness.

Now, the two professors have published this result in the journal Environmental Science and Technology Communications with an impact factor of 6.934.

Can rice cookers really be sterilized?

To prove that N95 heated in a rice cooker can still be used, the researchers conducted some experiments.

The first step is to prove that it can really kill all viruses .

They found some different types of viruses, including adenovirus, rotavirus, Tulane virus, etc., as well as other coronaviruses besides the new coronavirus.

Then, mix the virus suspension with artificial saliva and start inoculating the mask.

Several schemes were used during the vaccination process. Some were to vaccinate at different parts of the same mask, and some were to cut the mask into small pieces and soak them directly in the virus liquid.

After heating in a pot, the virus is tested.

But no matter which experiment was used, after 50 minutes, the viruses were killed or their concentration was lower than that which could infect humans.

For example, the Duran virus was almost completely eliminated after being heated in a rice cooker for 30 minutes.

In addition, we know that the new coronavirus will die if it stays at 56°C for 30 minutes, so the temperature of the rice cooker can kill the virus.

Will “dry pot” destroy the performance of the mask?

The second step is to prove that the disinfected masks can still be used .

In the previous experiment, some N95 masks were cut into small pieces with a diameter of 5 cm.

Now, take these small pieces out of the pot and place them on the filter holder and place it in the airtight container made of polypropylene.

Then, a constant output nebulizer was used to nebulize 2% saline (sodium chloride solution) to generate sodium chloride aerosol.

Now, then these aerosols are sent into the polypropylene space where the mask fragments are placed, and then the particle concentration before and after filtration is calculated.

The speed at which aerosols pass through mask fragments is 9.4 cm/s. At this speed, the filtration efficiency of mask fragments exceeds 99%.

As the number of reuses increases, the filtering performance of the mask slowly decreases, but it can be maintained above 95%.

Even if it is heated in a pot 20 times, the filtration efficiency can still reach 97%.

Therefore, the performance of the mask is still guaranteed.

Finally, the researchers reminded that this method is only used for N95. If you are using other masks, don’t consider this method for now.

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https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7374934/