How do you tell if a coffee mug (or any other dish, for that matter) is safe to use in the microwave? I buy a lot of mugs at thrift shops and yard sales, so some of them are probably old enough that they might not be safe. I seem to remember something along the lines of filling the mug with water and microwaving on high for a certain length of time and if the handle gets hot, that means it's not safe for the microwave. But I can't remember, like how long is the length of time you're supposed to do it; can anybody help?
Lynn from Chico, CA
By Lynn Marler
By (Guest Post) 01/25/2007
Two minutes. Don't forget that sometimes the water gets so hot that it will "explode" when the mug or other container is jiggled. (Let it rest a few seconds.) This has caused serious burns on people's faces (and other parts, such as hands). Unless one's microwave is of very high wattage, two minutes will be okay, though. I have some of these mugs, too, and have been disappointed that so many of them are not microwave-safe.
Dear Lynn, I only tested this myself a few days ago. Place the dish you want to use in the microwave and place a microwave safe dish beside it with a cup of water in it. Microwave for 1 minute on high and if the dish you want to use is cool, it is safe to use.
By Susan (Guest Post) 01/26/2007
Hi, I recall the method you mentioned. I'd say if your mic is average wattage etc, that if you heat it for about 1 to 1 1/2 minutes and the handle gets hot, then don't use it. If not for anything else other than the heat of the handle causing someone to drop the hot liquid.
By JudyR (Guest Post) 01/26/2007
I recently got a very bad burn on my fingers from a mug I put in the microwave. I had just purchased a couple mugs from WalMart. The bottom said microwave/dishwasher safe. AFTER I got this horrible burn - I turned the mug over and read...the next line..."may get hot in microwave". Hot ? It was blistering hot. I have never seen this disclaimer on dishes/mugs before.
JudyR's response will be one more reason I don't shop at WalMart.
The age of the (mug, dish, whatever) won't tell you much. I have a lot of diner dishes my grandmother used in her diner back in the 1930s and they work just fine in a microwave. On the other hand, my mom bought a nice set of dishes about fifteen years ago, and it turned out they were not microwaveable. When you microwave them the glazing cracks. From what I've seen most of the older stuff does well (and I'm not talking about fine china because I don't know about that). If you are buying a new set of dishes I would make sure they are microwave safe, and I'd make sure if there was a problem I could return them for a full refund.
By anon (Guest Post) 01/26/2008
My wife was just burned by a non-microwave safe coffee mug that was only microwaved for a minute and 45 seconds, so I disagree with the two minutes test.