Compact Disc Bronzing - Preventing Bronzing

Preventing Bronzing

Unlike other types of CD rot, most of which are caused by improper handling and/or storage of CDs, bronzing is due to a fault in the manufacturing process and can therefore neither be prevented nor stopped once it has begun.

However, storage conditions certainly seem to contribute to the speed of the decay, as some bronzed CDs were already reported as unreadable in the mid-1990s, whereas others were still playable by 2012. As it was noted that CDs stored in paper sleeves were deteriorating sooner and faster than CDs stored in jewel cases, it is likely that storing CDs in an acid-free environment might slow down the bronzing effect. A minimum measure would be to remove the booklet and paper inlay from the CD's jewel case, though it might be advisable to store affected CDs in envelopes made of alkaline paper inside a box made of acid-free cardboard. Plastic or vinyl sleeves are not considered safe because the softening agents in the plastic may lead to further corrosion; polypropylene sleeves are a notable safe exception. Similar measures are used for books suffering from acid deterioration.

Because the recording is in the polycarbonate, not the reflective layer, the IASA has pointed out that in principle it would be possible to split the sandwich and re-coat the polycarbonate with aluminium to conserve the data on the disc.