How do I responsibly dispose of backup tapes?

Solution 1:

You could read the Guidelines for Media Sanitization (PDF) of the National Institute of Standards and Technology.

Reel and Cassette Format Magnetic Tapes

Clear magnetic tapes by either re-recording (overwriting) or degaussing. Clearing a magnetic tape by re-recording (overwriting) may be impractical for most applications since the process occupies the tape transport for excessive time periods. Clearing by Overwriting: Overwriting should be performed on a system similar to the one that originally recorded the data. For example, overwrite previously recorded classified or sensitive VHS format video signals on a comparable VHS format recorder. All portions of the magnetic tape should be overwritten one time with known non-sensitive signals.

Degauss using an NSA/CSS-approved degausser. Purging by Degaussing: Purge the magnetic tape in any degausser that can purge the signal enough to prohibit playback of the previous known signal. Purging by degaussing can be accomplished easier by using an NSA/CSS-approved degausser for the magnetic tape.

Incinerate by burning the tapes in a licensed incinerator

Shred

Preparatory steps, such as removing the tape from the reel or cassette prior to destruction, are unnecessary. However, segregation of components (tape and reels or cassettes) may be necessary to comply with the requirements of a destruction facility or for recycling measures.

Solution 2:

May I suggest Thermite?

Solution 3:

Fire is your friend.

Solution 4:

If the number of tapes is reasonable (<100) then there are any number of ways to permanently destroy them. Be creative.

If the number of tapes is much greater (>500) then I would contact a shredding company. Even if they don't handle tape media I'm sure they would have knowledge of those who would.

Solution 5:

I'll tell you what we do

1- 2 minutes on the degaussing machine 2- sharp scissors and about 20 minutes to make confetti. alternately, a good office shredder.