Will microwave kill the virus that like COVID-19? This is an important question, especially when people are now using cotton masks that are periodically washed and disinfected.
While bleach and alcohol can be used for surfaces, and hydrogen peroxide can also be used for the disinfection of textiles, if nothing else is available, we need to know other options for disinfecting masks.
Does Microwave Kill Coronavirus?
Will microwave kill coronavirus in practice? In reality, microwave and coronavirus are lethal enemies, because microwave disinfection has long been used in hospitals for items that don’t melt, like dental instruments, contact lenses, and even urinary catheters for intermittent use.
It works because microwave ovens create friction between water molecules in an electrical field. Unlike other sources of heat, what microwave ovens do is generate heat by exciting the individual molecules in food and other items that are placed for heating and sterilization. The CDC reports that current data is promising for microwave ovens, and these machines are an effective microbicide.
What is interesting here is that you do not even have to buy a larger microwave oven or a “professional one” to get good results. A regular household microwave oven transmitting 2.4 GHz is sufficient to disinfect items that won’t melt inside the oven. Microwave ovens are effective for inactivating or killing off different kinds of bacterial culture, from mycobacteria to viruses.
The period for inactivating challenge organisms depends on the target pathogens. Sometimes the challenge microorganisms die within a minute, while others require an average of five minutes of exposure to the microwaves before they are inactivated.
The destruction of most microorganisms happens after the four-minute mark, so if you are disinfecting items like masks that you use to protect yourself from COVID-19, you may want to wash them first with lots of soap, bleach, and water. Then you can pop them in the microwave for four to five minutes for the final disinfection.
Why and how does the microwave kill viruses and bacteria?
While the data on COVID-19 and the summer months remain inconclusive, it’s important to remember that human pathogens can adapt to environmental factors. So right now, medical experts are cautious about getting people’s hopes up that the summer months will be enough to slow down the spread of the novel coronavirus. However, if you are asking about the heat generated in a machine like a microwave oven, then yes, that kind of heat can inactivate viruses and bacteria.
Heat can easily destroy proteins and RNA in viruses, rendering viral particles incapable of reproducing themselves. Microwave ovens have long been used to disinfect items like dental tools, scrub pads, and sponges, too. The heat generated by the microwave energy is sufficient to kill off many human pathogens, including coronaviruses.
What is the correct way to kill viruses with the microwave?
Below are some guidelines for using microwave ovens for sterilizing microwave-safe items:
- While effective, sterilizing things in the microwave oven does pose a slight risk of fire. So yes, doing this just might be a fire hazard if you don’t do it properly.
It’s important that if you are sterilizing or disinfecting anything with textiles, the textile or synthetic absorbent material is completely wet. Never sterilize textile or dry absorbent material, as a fire can erupt at any time.
- There is no need to overdo sterilizing objects – two to four minutes is sufficient. It is also necessary to monitor the items being sterilized. Different objects have different flare points, and we are not sure if what you are disinfecting has components that catch fire quickly.
- To be truly effective, the object being disinfected has to rotate within the microwave oven properly, so that the microwave radiation will be able to heat all of the parts of the object/s effectively.
- Never microwave anything with metallic content. Disposable surgical masks that have small metal nose pins should not be placed in a microwave oven. Doing so may result in fire or a broken appliance.
- If you can microwave your items for at least two minutes, you will be able to knock out at least 99% of all the bacteria and viruses there. This is the reason why people are sterilizing their kitchen sponges and plastic scrubbers in their microwave ovens because microwave radiation simply works.
- Textile that is soaked in animal fluids like blood can also be sterilized using a microwave oven. One study found that microwaving gauze with a brain-heart solution or blood agar can inhibit the growth of microorganisms.
The results of microwaving the inoculated gauze were similar with the results culled from a humid heat sterilizer. Humid heat sterilizers function at temperatures of up to 121° Celsius (249.8°F) at 1.1 atmospheric pressure. This just shows that in the absence of more expensive sterilization techniques, you can use microwave ovens to your advantage.
- The minimum power for a microwave oven is 360 watts for sterilization. Studies show that microwaving cigarette filters and syringes for 3 minutes were capable of inactivating the hepatitis C virus, which is one of the most widespread viral diseases spread through syringes and bodily fluids.
- The safest setup is using a 600-watt microwave oven and sterilizing for at least two minutes. While in-vitro studies state that you need about 60 seconds, we are talking about sterilizing items that were outside, so dirtier and pathogens are sticking to them.
- There is currently no direct study on the use of microwave ovens for inactivating COVID-19. However, scientists have tried inactivating related viruses (parainfluenza), and the impact of microwave radiation is quite promising.
Scientists state that three minutes of microwave radiation from a 600-watt microwave oven is enough to inactivate all of the viral particles in a petri dish.
- To check if your microwave oven is sufficient for the task ahead, check the Microwave Energy Output of your microwave oven at home. Ideally, the range of output should be 700 – 1,200 watts. The microwave oven should be able to blast out microwave radiation at 600 watts at least. Anything higher is better, but not necessary to get a good result.