What is highest temperature allowed for storage of burned (and unburned) CD-Rs/Pressed CDs (if different)?
Here’s what can be gathered from the NIST Special Publication 500-252
"Care and Handling of CDs and DVDs â€”A Guide for Librarians and Archivists":
General recommendations for long-term storage conditions:
For archiving recordable ® discs, it is recommended to use discs that have a
gold metal reflective layer.
[left]Archival Storage Facilityâ€”Recommendation for storing CDs and DVDs together[/left]
[b][left][font=Courier New]Media: CD, DVD[/left]
T[/b]emperature: Less than 20Â°C (68Â°F) Greater than 4Â°C (39Â°F)
Relative Humidity (RH): [/font]20% to 50% RH
A temperature of 18Â°C and 40% RH would be considered suitable for long-term
storage. A lower temperature and RH is recommended for extended-term storage.
A table from the publication can be seen below.
This doesn’t mean that optical media will spontaneously self-destruct if stored at temperatures or humidities outside the recommended ranges.
Another way to answer your question is to look at how fast your CD-Rs will degenerate at high temperatures.
Here’s what Kodak have to say about this (Storing KODAK CD-R Media):
I store my data backup CD-R’s in a fireproof box. At what temperature will KODAK CD-R’s sustain for 1 hour?
We do not have data to answer your question directly. Kodak’s standard accelerated ageing condition is 80 degrees Celsius, 85% Relative Humidity. Kodak Ultima media typically survives a number of weeks at that condition. Limited testing has been done at higher temperatures. This testing suggests that one hour at 100 degrees Celsius should not present a problem. Certainly any temperature at or near 120 degrees Celsius would. CD-R substrates are molded from polycarbonate. The glass transition temperature for polycarbonate is approximately 140 degrees Celsius. If the temperature gets within 20 degrees Celsius of the glass transition temperature, there is a likelihood of significant disc deformation.
This is by no means scientific or a recommendation that anyone else do this, however it may put some minds at ease a bit.
I live in Tucson, Arizona - one of the sunniest and hottest places on the planet. I leave my pickup truck parked outside my office all day in direct sunlight with the windows rolled up. The temperature outside reaches 110+ degrees in the summer. Inside, it must be 130-150 or so for hours on end, day after day, all summer. At any given time, I have between 10 and 50 CDs in my truck - some pressed and some burned. I sometimes have DVDs in there too. I make no special efforts to keep the disks out of direct sunlight. (I don’t leave them out on the dashboard either - just on the seat where they usually get a couple hours of direct sunlight a day. Some of them in jewel cases and some just naked.) I have never had any heat related problems whatsoever with any of the CDs or DVDs I leave in the truck. I have had some jewel cases melt on me, but I’ve never had any disks damaged.
My conclusion: No natuarally occuring condition on the planet Earth (with the possible exception of a volcanic eruption) is hot enough to adversly affect CDs or DVDs. This is nothing to worry about. This is just my opinion and is based on absolutely nothing by my personal experience. I take no responsiblity if your CD melts in your car.
Maybe we can hear about people’s experiences with how volcanic eruptions have influenced their optical media?
In a related note other people in these forums have reported that leaving CD-R or DVD+/-R(W) media in direct sunlight can make them unreadable in a couple of weeks - not due to the effect of heat but due to the effect of light!
Thanks to all for the info.
The generally accepted max temp for all computer media is 125’F. This is the temp that fire-safe vaults are designed to maintain for 1 hr.
As for long term storage, the 68’F max is a good guideline.