Why not obtain copies of MSDS sheets (paper or electronic version), scan them to a .pdf file, and change the reference in the Excel spreadsheet from the internet link to the location of the scanned files. Another problem with linking to internet sites is manufacturers change locations of their files/MSDS data. If you have the data on your own computer or server, you know exactly where it is (hopefully

) .
Keep it simple and functional.
I currently save my certificates of calibration this way and I helped my sister-in-law to set up her MSDS sheets this way also.