Microwave Warning

[weatherlover427]

Subject: Microwaving Water!
I did not know this, did you?

A 26-year old man decided to have a cup of coffee. He took a cup of water and put it in the microwave to heat it up (something that he had done numerous times before). I am not sure how long he set the timer for, but he wanted to bring the water to a boil. When the timer shut the oven off, he removed the cup from the oven. As he looked into the cup, he noted that the water was not boiling, but suddenly the water in the cup "blew up" into his face. The cup remained intact until he threw it out of his hand, but all the water had flown out into his face due to the build up of energy. His whole face is blistered and he has 1st and 2nd degree burns to his face which may leave scarring.

He also may have lost partial sight in his left eye. While at the hospital, the doctor who was attending to him stated that this is a fairly common occurrence and water (alone) should never be heated in a microwave oven. If water is heated in this manner, something should be placed in the cup to diffuse the energy such as a wooden stir stick, tea bag, etc. (nothing metal). It is however a much safer choice to boil the water in a tea kettle.

GENERAL ELECTRIC's RESPONSE:
Thanks for contacting us, I will be happy to assist you. The e-mail that you received is correct. Microwaved water and other liquids do not always bubble when they reach the boiling point. They can actually get superheated and not bubble at all. The superheated liquid will bubble up out of the cup when it is moved or when something like a spoon or tea bag is put into it.

To prevent this from happening and causing injury, do not heat any liquid for more than two minutes per cup. After heating, let the cup stand in the microwave for thirty seconds before moving it or adding anything into it.

Here is what our local science teacher had to say on the matter: "Thanks for the microwave warning! I have seen this happen before. It is caused by a phenomenon known as super heating. It can occur anytime water is heated and will particularly occur if the vessel that the water is heated in is new, or when heating a small amount of water (less than half a cup).

What happens is that the water heats faster than the vapor bubbles can form. If the cup is very new then it is unlikely to have small surface scratches inside it that provide a place for the bubbles to form. As the bubbles cannot form and release some of the heat that has built up, the liquid does not boil, and the liquid continues to heat up well past its
boiling point.

What then usually happens is that the liquid is bumped or jarred, which is just enough of a shock to cause the bubbles too rapidly form and expel the hot liquid. The rapid formation of bubbles is also why a carbonated beverage spews when opened after having been shaken." If you pass this on ... you could very well save someone from a lot of pain and suffering.

[ColdFront77]

Joshua, interesting and very informative information. Thank you very much for posting it.

The mugs of water I have boiled to prepare "Soup-In-A-Cup" haven't been too old... the only reason why this hasn't happened to me.

[weatherwunder]

Tom, I think what the article is saying is that new cups are more likely to have this happen. Be careful!

[Miss Mary]

I carefully boil water for making iced tea, in the microwave. When I remove the 2 cup glass measuring cup and place it on the counter, adding the tea bags then, it bubbles up like crazy. This is at least 5 feet away from me. Something so simple can go wrong, I can understand that happening! Think I might go back to the old fashioned way of boiling water on the stove, in a metal pan. Thanks for timely reminder.

[wx247]

Didn't know this. Thanks for sharing!

[Colin]

Wow...I didn't know this! :o Thanks for sharing.

[coriolis]

This has happened to me too, when re-heating last night's coffee in the microwave. When I put in the sugar, it foams up like a glass of soda. Adding sugar (or salt for that matter) creates even more heat as the crystals dissolve in the water.


I don't think you need to worry about cup-a-soup, Cold Front, if it has noodles and stuff in it.

[GalvestonDuck]

From Snopes.com: http://www.snopes.com/science/microwav.htm

Yup, it's true.

[TexasStooge]

WOW!! Didn't know this either, did it several times & nothin' happened, thanx for sharing!

[ColdFront77]

Tom, I think what the article is saying is that new cups are more likely to have this happen. Be careful!

Jeff, I understand that this is more likely to happen with new cups, that is why I mentioned it in my response.

I don't think you need to worry about cup-a-soup, Cold Front, if it has noodles and stuff in it.

Sometimes when I prepare my cup-a-soup, I heat up a mug of water, then pour it into the cup with the noodles.

[blizzard]

I've haad this happen to me also. Thanks for posting the warning, not all are aware of this phenomenon

[Anonymous]

I was not at all aware of this phenomenon.

Thank you very much for posting it!!!

-Jeb

[JCT777]

I have heard of this, which is why I rarely heat a cup/mug of water in the microwave.