I've used virtually every type of tape on the road over the last 30 years. Any "certification" of a data tape is just hype and advertising. No tape can be considered reliable until it is written to and that reliability is canceled when you scratch the tape for reuse.
Over all this time, tape products have only improved in quality and reliability. I don't think I've had 3 tapes that were bad when used initially over the last 10 years. I've had tapes that were still usable after years of backup rotations. I have seen tapes start to throw errors after a time. Retire any tapes that give hard errors.
Look to the tape specs. How many passes over the read/write head are recommended? How many years is that given your rotation cycle? It's probably more important to look to your tape storage conditions than the manufacturers quality. Keep temperature and humidity within specifications. Don't drop the tape on the concrete floor. Don't use tape for a door stop. Clean your tape drive at appropriate intervals. Don't forget that the recording on tape has a "shelf life". Any tape recording more than 5 years old needs to be rewritten. I know DLT, LTO, etc. say 10 years. Go for 5, you'll need the other 5 years to get management to foot the cost.
If your supervisor doesn't understand the technology, you have my deepest sympathy.