How do I programaticaly find out if polymer is not working?

We are using polymer in our web app. The problem we are facing is, although we know that in older browsers (Chrome 35 and before, FF 28 and before etc.) polymer is not supported, is there a way that we can find out pro grammatically if any os / browser combination is not supporting polymer.

Though we are serving different websites for different browser version depending on their support of polymer, we are still getting user feedback that the site is not loading. The user sees a blank white page if polymer don't load.