Are you using CDs and DVDs as a long term storage medium?

During a recent presentation I was asked again on the use of CD/DVDs for long term storage of business records. In this article I will discuss three areas that may assist you in determining the viability of using the medium for either short or long periods.
• Type of CD/DVDs
• Optimum Conditions
• Migration

Type of CD/DVDs

Compact Disks (CDs) are optical media. While guidelines from different articles on the subject state the medium can be used for long term storage, I recommend reviewing an excellent article by Fred R. Byers on the “Care and Handling of CDs and DVDs, A Guide for Librarians and Archivists”, Oct 2003 (www.clir.org/pubs/reports/pub121/pub121.pdf ).

Not all CDs are equal or of archival quality. You should also check the archival quality of the media sold by the manufacturer. A Dutch PC-Active magazine did an extensive CD-R quality test on the different CD-R brands and found that some had become completely unreadable in less than 20 months.
Cut and Paste: http://www.cdfreaks.com/news/CD-Recordable-discs-unreadable-in-less-than-two-years.html.

Optimum Conditions

As reflected in the article by Fred R. Byers, the optimum recommendations for long term storage conditions for CD/DVD media is a temperature of 39 degrees F (4 degrees C) to 68°F (20°C) with relative humidity (RH) of 20% to 50% RH.

Unless you have a climatically controlled environment I doubt many of us meet the minimum standard for storing CDs. So if you don’t have a controlled environment, you must review your collections periodically to insure the media can be read.

Migration

As a consultant I have observed that many organizations depend on CD/DVDs as a storage medium. If you are investing in a system to manage your electronic records in CD/DVD format, then you must consider the need to insure the availability of the information in the future. The following points cannot be over- emphasized:

• You must have a policy/procedure to insure the collection is migrated from older to newer technology in a timely fashion when newer technologies make your current system obsolete.
• If you are retaining your records on CD/DVDs for more than 8 years you should have a process to insure the collection is migrated before the medium deteriorates which could be within only 18 months (see first two points).

Depending on the amount of records being maintained the migration could become an expensive and time consuming proposition. On the bright side the retention period for the majority of business records normally does not have a long term retention requirement.

After you have considered the points mentioned above, and you are still convinced that you want to retain your records in a CD format, then you must consider the benefits you will derive from converting or retaining the documents to CDs. Look at cost of retaining in electronic format as follows:
• Are the records (1) in electronic format; or (2) in paper format?
• Can we destroy the paper copies when transferred to electronic format?

If the records are already in an electronic format your expense to move the documents to CD should be minimal. However, if you are considering scanning the paper to electronic format your cost may greatly exceed the benefits. You need to closely review each project on its own merits. If you still have the requirement to maintain the paper documents then you must again closely review the cost benefit.

I still advocate using CD’s where appropriate, but I am mindful of the problems and costs that may occur in the long term.