Introduction
We have confirmed that the problem can only occur when a damaged CD ROM disk is used in the CD ROM drive. Our recommendations are that users should check all CD ROMs before each use, to ensure that they contain no cracks. If they are cracked you should not use them. You should especially look at the clear plastic on the inner rim of the disk – cracks here are the cause of disk shatter.

Cracks are more likely in poor quality media which we believe have become significantly more prevalent recently and are made of more brittle materials. Our care recommendations for CDs are:

• When not in use remove CDs from the computer.
• Always store CDs in the packaging supplied with them.
• Always store CDs out of direct sunlight, and away from heat sources.

Are the Window Box/RM/LSP CDs all safe? Can you give us lists of safe CD Media?
Most media may potentially crack and as such any CD should be checked before inserting to the CD ROM drive. The nature of CDs may change over time, and through age become naturally more brittle and will therefore have an increased risk of cracking. That is why we recommend that every CD is checked every time before use

What media is safe? Audio CDs? What do I buy?
Most media may potentially crack and as such any CD should be checked before insertion into the CD ROM drive. The nature of CDs may change over time, and through age become naturally more brittle and will therefore have an increased risk of cracking. That is why we recommend that every CD is checked every time before use. There is, however, a very significant difference in the propensity of some disks to crack

Does it affect DVDs?
DVD disks may be vulnerable to crack but the drives supplied by RM do not spin at the high speed required for there to be a risk of disk shatter. However, faster DVD drives are now available on the market that spin fast enough to shatter disks.

Does RM check media before shipment?
It is often not possible for RM to check media contained in third party products which are shrink wrapped for licence purposes. RM will though re-assess our current Quality Assurance process in response to this problem.

How can I prevent CDs cracking?
Cracks are more likely in poor quality media that we believe have become significantly more prevalent recently and are made of more brittle materials. Our care recommendations for CDs are:

• When not in use remove CDs from the computer.
• Always store CDs in the packaging supplied with them.
• Always store CDs out of direct sunlight, and away from heat sources.
• If you are buying a large volume of CD-R's, you should consider assessing their material flexibility and whether they are easy to crack around the inner rim.

How big does a crack have to be?
Our experiments and research show that a crack even as small as 5mm can produce this problem. Our advice is that if there is a visible crack on a CD then you should not use it.

What does a crack look like?
We have provided an image on the web site, which illustrates where to look on a CD ROM.

Click to enlarge

What happens in disk shatter?
In a 52X speed drive the disk can rotate at greater than 10,000 rpm. Through this a small crack may grow across the disk, then the disk can shatter into fragments and in exceptional circumstances parts of the disk may be ejected through the front of the drive. For a full description of the issue we recommend that you visit our web site

Are there alternatives to CDs?
If you follow RM’s advice there is no need to stop using CDs.