MSDS - why you need them.

A MSDS (Material Safety Data Sheet) is a form produced by the manufacturers of all most all chemicals. Large businesses are required to have the MSDS information at hand for any of the products they use in their daily work. So why do you need them for the products you use? Well, mostly you don't, but I can give some compelling reasons to seek them out.
1) MSDS list the ingredients of the product you are using. Yep, ever wonder what was in some of the finishes you use? An MSDS will tell you, down to the percent. Poor labelling of consumer packaging no longer has to stop you from knowing exactly what you are exposing yourself to, or for that matter whipping up some of your own if that is cheaper for you. Many manufacturers rely on the "Secret" of what is in their stuff to stay in business.

2) The real purpose of MSDS sheets; safety - it is always good to know what you are being exposed to. Everything from alergic reactions, wondering how to store safely, or is it safe to mix with another product, etc.

Here are a few to get you started.
Rockler provides MSDS for the chemicals they sell and even have a nice search engine. As they sell the Sam Maloof finishes, kinda interesting reading!
Highland Hardware also has a list of MSDS for what they sell.

MSDS online is a pay service, but allow trial use, so if you have one in particular that you are interested in looking up, this may be your best option.

Oh, and I've noted that even if a .COM company doesn't have MSDS sheets online for the public, sometimes the Canadian version of the same company / site will.

Another tip - sometimes you can get the information you need simply by asking for it, either by mail, phonecall or webform. "I need the MSDS information for product X, please." Will generally get the job done. I like the "Contact Us" webforms that most companies provide for their sites.

This may be another good way to track down info.

So if your interest is simply casual (What is in this stuff? / Can I make my own version more cheaply?) or because you have concerns (Last time I used this stuff, I got a rash.) the right MSDS is where you need to go for the answers.