DON'T USE PLASTIC CONTAINERS IN YOUR MICROWAVE

New health warnings say you should not heat food in plastic containers or with plastic wrap. Some of the plastic chemicals will get in the food and into your body. We use 1930s covered glass refrigerator containers.

DON'T USE AMMONIA TO CLEAN PLASTIC

I just got a new plastic storm door and was told not to clean it with Windex because ammonia will eventually cause the plastic to become cloudy. Not all plastic reacts the same way, but just to be sure don't use ammonia or ammonia-based cleaners on any form of old plastic, especially plastic purses and jewelry.

ARE THE PIANO KEYS IVORY?

Q: I bought a baby grand piano at an estate sale for $500 in 1972. It is labeled "Made and Guaranteed by The Packard Piano Co., Fort Wayne Ind. Est. 1871/Bond Piano Co." The serial number is 22190. I would like to know what the white keys were made of and the value of the piano today.

A: Albert Sweetser Bond was one of the owners of Packard Piano Co. In 1911 a group of Packard stockholders founded Bond Piano Co. In 1913 they decided it was inefficient to run two separate operations and Packard began manufacturing pianos with the Bond name on them, while continuing to make pianos with the Packard name. Bond pianos were made through 1925. The serial number on your piano indicates it was made in 1924. Piano keys were made of ivory or celluloid before the 1950s, when plastic keys were first used. Ivory keys were made in two pieces with a seam between the front and back part of the key. The keys are grained and may look yellowish. Celluloid keys were made in one piece and are off-white. A piano has to be seen and played to be appraised since the condition of the sounding board and internal mechanism helps determine the value.