Re: What is causing the 'bad' odor from my mouse pad?

I will try to answer your questions in the order you asked them:

1. What is it made of (I believe it is the same rubber material now used on the soles of many sandal type shoes)?

Well, a web search (using Metacrawler turned up little results. All I found was that some mouse pads are made of something called "SBR Textured Rubber," whatever that is. A web search on that turned up nothing. As to the rubber used in sandal-type shoes, I know that Teva™ uses something called "Spider Rubber®." Maybe its the same, maybe not.

2. Does the fact that there is an odor mean that particles of the mouse pad are in the air? Does it have a high vapor pressure?

Yes, it most definitely means that particles of the mouse pad are in the air. Otherwise, you couldn't smell it! As to the vapor pressure, I have no idea but I imagine it is rather low.

Why would some people find the smell objectionable and others not. If something smells bad, are the senses trying to tell one to avoid the smell, i.e. is everything that smells bad best to be avoided or is it possible for something to smell bad but at the same time be a substance that is either neutral or actaully beneficial to an organism?

Mmmmmmmm. I'm pretty sure that a good or bad smell isn't a really good indicator of how healthful a substance is. Lots of medicines stink. On the other hand, they say that the odor of cyanide is much like cherries. But if you are around long enough to smell it, you are as good as dead.