Copyright OSTA 2001
All rights reserved.

  Understanding
CD-R & CD-RW


Author's Notes
Physical, Logical and File
System Standards

Recording Hardware
Recording Software
Recording Speed
Physical Compatibility
Disc Size and Capacity
Audio Recording
Digital Pictures on CD
Duplication, Replication
and Publishing
Disc Labeling
> Disc Handling, Storage
and Disposal

Disc Longivity
Disc Testing and
Verification

Disc Construction and
Manufacturing

Appendix A - Further
Reading and Resources

Appendix B - Industry
and Product Contacts
About OSTA
About the Author

  CD-Recordable Glossary

  bluelaser

  White Papers

  Archived Storage (COSA)

  Optical Websites


DISC HANDLING, STORAGE AND DISPOSAL

What is the best way to handle and store a CD-R or CD-RW disc?
A disc should always be handled by grasping its outer edges, center hole or center hub clamping area. Avoid flexing the disc, exposing it to direct sunlight, excessive heat and/or humidity, handle it only when being used and do not eat, drink and smoke near it. Discs should be stored in jewel cases rather than sleeves as cases do not contact the discs’ surfaces and generally provide better protection again scratches, dust, light and rapid humidity changes. Once placed in their cases discs can be further protected by keeping them in a closed box, drawer or cabinet. For long-term storage and archival situations it is advisable to follow manufacturer instructions. For further information consult the international standards for preserving optical media (ISO 18925:2002, Imaging materials — optical disc media — storage practices).

Should fingerprints and dust be cleaned off a CD-R or CD-RW disc?
CD technology is robust and employs several design elements to minimize the effects of fingerprints and minor scratches on data integrity. The first line of defense comes from the physical structure of the disc and the location of the data-bearing marks and lands. The reading laser beam shines through the disc’s substrate focusing beyond the contaminated surface and directly on the marks and lands beneath. In concert with advanced error detection and correction capabilities minor debris and abrasions are largely ignored. That said, handling care should be taken as above and a dusty disc should be blown off so that the dust does not enter the drive mechanism and accumulate on the lens or other optical components. It should also be noted that fingerprints, dust and scratches have a greater impact on recording than is the case with reading since the contaminants reduce the effectiveness of the writing laser by obscuring its beam from the disc’s recording layer.

What is the best way to clean a CD-R or CD-RW disc?
Dirty discs should be carefully cleaned using a soft dry lint-free cloth or camera lens tissue. Holding the disc by its outer edges or center hole gently wipe outward from the center hub toward the outside edge of the disc (just like the spokes of a bicycle wheel). Do not wipe the disc using circular motions as any scratches created will do the least damage if they cut across the track of marks and lands. More stubborn fingerprints or stains can be removed using a soft dry lint-free cloth lightly moistened with water or a commercially available CD cleaning fluid. Do not use vinyl record cleaners, lacquer thinner, gasoline, kerosene, benzene or other solvents, as they may damage the disc. Manufacturer directions should always be followed.

Can scratched and damaged CD-R and CD-RW discs be restored?
Often it is less expensive and makes more sense to transfer the data from a damaged disc onto a new one rather than to try to restore the problem disc. For dealing with more badly damaged situations consumer disc repair kits are available while several companies offer CD restoration and resurfacing equipment and services. See the resource listing in the appendix for contact information.

Is it possible to recover data from damaged CD-R and CD-RW discs?
Several software packages are currently available which diagnose disc problems and help recover deleted, unreadable or otherwise inaccessible information. A number of companies also offer commercial CD data recovery services. See the resource listing in the appendix for contact information.

What is the best way to destroy unwanted CD-R and CD-RW discs?
For office and high volume production situations various CD destruction options are available including mechanical shredders, desktop devices which employ heat and pressure to make disc unreadable and grinders which abrasively remove the disc’s reflective and data-bearing recording layers. A number of companies also offer commercial CD destruction services and deal with classified or other sensitive materials. See the resource listing in the appendix for contact information.

Can unwanted CD-R and CD-RW discs be recycled?
A number of companies offer CD recycling services and are able to reclaim some of the materials used in the disc’s construction. See the resource listing in the appendix for contact information.