My mother owns a microwave oven that is about 20 years old. It looks like new and has always been well taken care of. However, I was wondering whether it is still safe to use. Should I have it tested for leakage? — KE, Milwaukee, WI
As long as it still cooks, it’s probably fine. Leakage of microwaves can only occur if the cooking chamber has holes in its metal walls. These walls include the metal grid over the front window and the seals around the door. If the metal grid is intact and the door still appears to close properly, the oven shouldn’t leak any more microwaves now than it did 20 years ago. However, to set your mind at ease, you can have it tested or test it yourself. www.comforthouse.com sells a simple microwave leak tester for $30. You can probably find similar devices at local appliance stores or, for a more accurate and reliable test, take your microwave oven to a service shop for inspection with an FDA certified meter. [Note added 1/10/97: I have finally found one microwave oven that leaks enough that a simple tester identifies it as dangerous—it’s the microwave oven in my laboratory and I’ve moved it around frequently and taken it apart several times for my classes. Evidently, I damaged its door hinges during my experiments because the door now sags a bit and doesn’t seal properly. The tester worked nicely in finding the leaks.]