I like SGIII's idea. Here's an expansion of it that might be more suitable for your situation, where I suspect the URLs are longer that ths used in SG's example.
Here the menus (Column A of Main) contain only the names of the sites or pages you want to link to. These names and the links associated with them are listed as a lookup table (Links), which may be placed on another sheet, if desired.
Note the two links to openstreetmap.org. The first will open a map page—either the last one visited from this computer or the 'home' location in England, depending whether there's a cookie on your machine recording the last visit.
The second is to a specific location—44.5298° N 110.3192° W—and is rather long to include as an item on a popup menu, similar to what would be required to open the specific page containing the safety data for a specific chemical on your list.
All Data on Links is directly entered, either via the keycoard, or by copy/paste in the case of the urls.
Main contains the formula shown, entered into B2, then filled down to the rest of the cells in column B.
The core part of the formula is shown in bold. The rest is a switch used to prevent calculation (and an error message) in rows where column A is empty.
PS: For the curious, here's the link to the OSM at Yellowstone: