CD Rot

They don't really last forever

[CD with corrosion]

There's not really much to say here. The pictures tell it all. The whitish areas are where the aluminum substrate has gone away. Flaked off, dissolved, stolen by Martians, whatever; it's gone.

The CD shown here is my copy of They Might Be Giants' Apollo 18. I've had it since 1992, and it's survived in a rough environment. The CDs were stored in a cabin for a year and a half. They experienced temperatures greater than 100F with high humidity. In the winter, they were in the same room as the wood stove. Since we only fired it up at night, the temperature could range from 30F to 70F in two or three hours. The CDs were less than eight feet away.

Some of the affected CDs have lost data, and skip on the affected areas.

The pictures are false-colored. After all, the substrate is gone. How can you show something that isn't there?

[Corrosion detail]

The second image is a close-up of one patch. Note how the aluminum has scalloped markings. I think these are fracture patterns due to repeated heating and cooling.

Out of 650+ CDs, I'd estimate that between 15 to 20% have this problem. I wonder if they were just poorly made. Since I've been in an apartment with a regular temperature, deterioration has slowed, but not stopped. Three CDs have actually lost data, and begun skipping or distorting at the affected areas.

CDs with problems include Big Audio Dynamite's Megatop Phoenix, Gary Numan's Strange Charm, and Talking Heads' Naked. Two Smiths CDs have begun skipping, and the second CD of Laurie Anderson's 4-CD United States Live has begun to distort on the last track.

So follow those important care instructions! Otherwise you'll end up with CD rot. Then you'll have to go see the Digital Dentist to get it taken care of. And keep in mind that even with a lifetime of care, CDs won't last forever.

Postscript, 5 May 2004

This page led an AP reporter to contact me for a story he was writing on CD deterioration (Peter Svensson, "CDs and DVDs not so immortal after all", 2004-05-05). I was pleased that he ended the article with my comment "I'm hoping they'll hold out till that next medium gets popular, and everyone gets to buy everything over again", a dig at the force-them-to-buy-it-again mentality of the recording industry. For the record, my next medium will be open and restriction-free. If nothing else suits, I'll move completely to Ogg Vorbis.

A few other things:

Last updated 24 June 2004
All contents ©1998-2002 Mark L. Irons