You can handle and get your fingerprints on the top side, the side with the label, but you should not scratch it so deeply that the scratch goes through the label or opaque coating. The bottomside of the opaque coating is what has the data on it. The bottomside of the opaque coating is glued to the disc. The disc itself is clear and the underside of the disc is clear. The drive reads the data from the underside of the disc looking through the clear disc to the top, the backside of the opaque coating where the data is.
You should not get your fingerprints on or scratch the underside of the disc because that will obstruct the view of the data but it does not ruin the data. You can always clean the underside of the disc to remove the fingerprints. And you may even have some success with removing scratches from the underside of the disc by polishing it.