There are a number of MSDS databases on the web. A good place to start is the Cornell MSDS database, which has ~250,000 MSDS files in the database.

The law requires you to have access to a Material Safety Data Sheet for each hazardous substance that is used in your lab.

It is prudent to check the MSDS before handling any material and reagent that you are not familiar with. MSDS provides not only information about handling and protection but also proper disposal procedures.