How can you tell if a lid is bakelite or just heavy duty plastic?

There are a couple of ways to test. The easiest is to hold the item under really hot water for a little while. After it's heated up, take a whiff. Bakelite smells sort of like formaldehyde. Plastic doesn't. Another way is to put some Scrubbing Bubbles on a q-tip and wipe the object with it. If the cotton turns yellow, it's Bakelite. There are also testing solutions you can buy that work well.

peri...you are a dear. Thank you for that practical info. It is something I could actaully do.