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Worried About Disc Rot? Here’s How To Look After Your CDs

Disc rot affects CDs, DVDs or LaserDiscs in different ways depending on how they’re manufactured and structured. Generally speaking, disc rot occurs due to chemical reactions with the reflective layer of the disc, ultraviolet light damage, scratches that expose the delicate and corrosive layer to environmental factors, or the deterioration of manufacturing materials.

CDs are often touted as the most durable physical music format because of the lack of contact during playback, compared to vinyl records and cassette tapes. Hell, I’ll admit, that with the exception of surface abrasions, I thought there was little you could do to corrupt a compact disc. Check out the BBC’s Tomorrow World’s totally convincing demonstration of the marvels of the new CD format:

Which is why I was caught off guard when I came across this article on disc rot on Motherboard. Great, as if it wasn’t enough that my stylus is wearing out my records, and my tapes are all unspooled – now I have to worry about the degradation of my CDs, DVDs and LaserDiscs as well. In fact, no one knows how long CDs can last. The answer is dependent on a number of factors, including where the disc was manufactured and how it is stored.

So why have we been treating these flat plastic donuts as an indestructible format for music and video when really they’re a delicate, carefully balanced alchemy of audiovisual data?

CD Disc Rot

In the case of CDs, disc rot is the effect of oxidation of the reflective layer of the disc, resulting in what can look like bronze discoloration, or as one victim described it, “a constellation of pinpricks” in the data layer of the disc. As anyone who’s suffered the misfortune of a scratched or scuffed disc CD will know, it doesn’t take a hell of a lot of damage to render the disc unreadable, and once that data is gone, it’s gone for good. CD degradation can be caused by mishandling or improper storage, but disc rot is typically caused by a chemical reaction with the reflective layer of the disc.

DVD Disc Rot

Though they look almost identical to CDs, DVD structure is a little different, using a plastic disc over the reflective layer. This is good news if you get a scratch on your disc as it means it’s less likely to reach the reflective layer and expose it to environmental damage. However, because of this structure, they can also suffer from delamination, where layers of the disc separate. On the disc, delamination can look like a coffee stain. Poor case design has been blamed by some as the case for DVD disc rot. During playback, DVD disc rot appears as the picture pixelating or freezing in a specific spot, skipping, or again, becoming unplayable.

Is Blu-ray Safe from Disc Rot?

It seems less prevalent than for CD, DVD and LaserDisc, but it would be unwise to rule out Blu-ray disc rot. There are a few reports of disc rot on Blu-ray which has been described as ‘small mould blooms’ below the surface, rendering the disc unplayable.

Laser Rot

The name given to LaserDisc’s own special brand of disc rot suggests the laser is to blame – similar to stylus wear – but again, it’s just the degradation to the disc. Speckling in the video and crackling in the audio worsen as disc rot advances. It’s usually attributed to oxidation of the aluminum layers by poor quality adhesives used to bond the disc halves together. Single-sided discs rarely suffer as badly as double-sided discs do.
LaserDiscs from specific manufacturers seem more likely to fall prey to laser rot. MCA DiscoVision discs are notorious for it, as well as discs pressed at Sony DADC in Terra Haute. Conversely, manufacturers like Kuraray were well known for their meticulous practices and have seen few instances of laser rot, to date.

Can I Prevent Disc Rot?

Unfortunately there doesn’t seem to be a surefire way to prevent disc rot due to many instances appearing due to manufacturing faults. However, proper care will help from exacerbating the problem, and it’s a timely reminder that your discs are by no means indestructible.
While some of the following tips are eye-wateringly obvious, they’re also often ignored. So let’s take it from the top.

Tips For The Correct Treatment Of Your Discs:

  • Handle your discs correctly, touching only the outer edges and hole in the center. While it’s probably second nature by now to be cautious with the reflective underside of discs, you should also be careful of the top, printed layer as damage to this side can also impact playback.
  • Store your discs in an upright position. Avoid keeping them in stacks, much like you would vinyl records. They should also be kept in a cool, dry environment.
  • Keep your discs in jewel- or keep cases rather than paper sleeves. Anchor the disc using the anchor pin in the center of the case. This is the best way to ensure you’re preventing scratches and damage inside the case. If the anchor pin is broken, it’s best to replace the case. Stick to one disc per case, and always return the disc to the case after play (e.g. don’t leave it on top of the stereo)
  • Label discs with a water-based marker. Hard tipped pens and chemicals can be abrasive and do damage to the data on the disc.
  • Check the quality of the disc before you buy – especially for secondhand discs. Look out for scratches, discoloration or what looks like pinpricks in the disc. If you’re buying recordables, spring for the higher quality version.

Discs made with gold as the reflective layer are less vulnerable to disc rot, as it’s a less corrosive material, though obviously, these are rarer than their (much cheaper) aluminum counterparts. And sadly, your CD-Rs and DVD-Rs are more likely to suffer from disc rot due to the type of organic dye used in recordables.

So the takeaway here is treat your discs well and they could last you a lifetime. Or they might not. I don’t know anymore, this disc rot thing has thrown my whole world into chaos.

Experienced the woes of disc rot on your CD, DVD, or LaserDisc collection? Tell us about it!

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21 Comments
  • […] An article on disc rot and deciding how to store this collection of CD-Rs/DVD-Rs […]

  • Feb 7,2019 at 4:04 pm

    The article states there’s nothing you can do. Wrong. For at-risk CDs, such as the PDOs in question, take the booklet out of the jewel case so it’s not touching the CD. Sulphur in the paper was the facilitator of the rot on those PDO discs. They may have rotted at some point because of the manufacturing flaw, but sulphur made it happen faster.

  • Feb 7,2019 at 8:22 am

    I also had disc rot on my copy of Chill Out by The KLF. My UK CD press of ‘Live ’93’ by The Orb also is rorring away.

  • Feb 7,2019 at 12:24 am

    I have noticed many Hip Hop CDs from late 80s-1992 by Florida and Georgia independent labels have gone dead or have some sound degradation. Probably all pressed on the same budget CD brand. Usually the silver fades and the CDs become somewhat transparent. I have purchased still sealed CDs from the 1980s and found them dead. I still like CDs due their convenience and ease of ripping. I hate CDrs. Most budget ones made in the 2000s have gone dead. Countless indie artists published on this format. Many only had their songs published CDr or sites that are now gone. These songs are at risk of disappearing like an antiquated format. Music only a decade or 2 old, yet lost forever. I always make a digital backup of any CDr immediately using EAC or XLD for Macintosh.

  • Feb 5,2019 at 4:19 pm

    Yes, the PDO issue affected about a 100+ CDs of mine. I managed to send many of them back to the manufacturer [even singles – especially singles seemed to be pressed by PDO Blackburn] and received about 80% of them in new, safe pressings. In cases where they did not have the title in question, they sent rough equivalents that made sense [i.e. for Lilac Time singles gone bad, they sent me a copy of the 2xCD compilation “Compendium”].

    I say the pinhole issue is separate from the bronzing and oxidation issues called “CD rot.” I was an early CD buyer from 1985. I looked at every disc I had that was an early pressing and the pinhole issue was widespread as the manufacturing of these new products was getting off of the ground. The only reason why a disc surface would not be plated fully is down to air bubbles during the electroplating process. I remember the first perfect CD I inspected with none of these pinholes in the data plating: the JVC Japanese pressing of Kraftwerk’s “Electric Cafe” for US warners in late 1986. In all cases but one, the error correction circuits in the CD player compensated for the lost date perfectly. There was one CD where it failed: Tracey Ullman’s “You Caught Me Out” in its first German pressing. I popped it in the CD player and it sounded like a helicopter was mixed into the music! I took it out and held it up to the light and I’d say that 20% of the data was missing. Not pinholes… there were craters in the plating.

    I am also a laserdisc collector and the idea of gluing two halves of an optical disc together was a bad one! Oxidation was a problem with Sony’s Terre Haute plant, but I also had Japanese import laserdiscs like Sylvian + Fripps’s “Live In Japan” – a 1995 pressing, become unwatchable within six months of buying it when released. As stated, the single sided LDs [I have an 8″ one] were more like big CDs. They should play without oxidation ever occurring. LD oxidation manifests as white dropouts in the video image, by the way.

  • Feb 4,2019 at 7:07 pm

    I recall CD rot only affecting some releases mostly pressed by PDO and the poor chemicals used. I know that ‘Hot Lemonade – A Guy Called Gerald’ and ‘The KLF – Chillout’ where affected by this with both discs having the bronzing effect – both pressed by PDO. I do own ‘Chillout’ and yes its has bronzed and there is part discolouration around the outer edge.

    I have CDs from 1996 owned from new which still look the same as the day I purchased them.

  • Mar 22,2018 at 11:00 am

    I’ve been collecting vinyl and CD records for over twenty years and it has not happened to me yet. I hope it will never happen to me.

  • Dec 29,2017 at 5:41 pm

    I’ve been burning daily since ’93 on, a Philips 5xx series SCSI burner, today it’s a Hitachi quad XL blu-ray drive, amongst several, with Sonys being the worst. Only have two cd-r’s with a sector issue, none of the audio discs show any deterioration. I’ve had to recover only one data disc since that time. I started my digital collection with TDK blanks and today use the JVC professional printable made in Tokyo.

  • Dec 28,2017 at 8:27 pm

    Good to hear the comments that disc rot is no longer an issue. After 20+ years, I finally decided to consolidate my CD collection into sleeves (plastic on the front, fabric/paper on the back). Should I be worried about storing my CDs in these? I really wanted to free up my walls for artwork.

  • Dec 27,2017 at 7:24 pm

    I’m wondering about these disc cleaning machines and what is a actually going on there. If they remove scratches, are they removing surface area making the disc even more vulnerable? Example: JFJ Easy Pro Universal CD/DVD Blu-Ray Repair Machine 110V with Extra Supply Kit (Up to 250 Repairs) https://www.amazon.com/dp/B00SU6UZTW/ref=cm_sw_r_cp_api_ev-qAb50T6MBD

  • Dec 27,2017 at 12:41 pm

    I had a few of the affected CDs at the time that went brown/gold and sent them off for replacement. I got new discs OK, but sometimes they did not return the highly prized sleeve, such as Siouxsie and the Banshees’ Stargazer CD-single. Moral: just send the disc.

  • Jul 15,2017 at 11:10 pm

    “Bishamondo 4 months ago
    I also clmsoled myself with the fact that the CD data is actually encoded in the polycarbonate substrate; the aluminum is only there to reflect light. So, technically, the data will likely remain on the discs long after the aluminum has oxidized beyond any reflectivity, and our great-great-grandchildren will be able to revive our old collections by somehow removing the upper laminate and oxide and applying a nice layer of gold. ;)”

    As a matter of fact I have a mispressing where the reflecting layer is missing on the disc, but I am able to extract the music with Exact Audio Copy :-)
    See https://www.discogs.com/Rush-Fly-By-Night/release/2938253 for a picture.

  • Mar 23,2017 at 10:50 pm

    Hello.

    To put the matter of ‘disc rot to a conclusion.

    No, it does not exist, it was a manufacturing fault on PDO pressed discs before 1998.

    The discs that have discoloured that i have are all PDO pressings from the Blackburn pressing plant that was shut down when the problem was discovered in 1995.

    If you have discs that are turning bronze then they should still play.

    If you have discs that appear to have the aluminium foil splintering at the edges of the disc, both the outer and inner edges of the foil area under the lacquer coating, then be prepared to throw them away or, if they are still playable, then, if at all possible, make a copy of the disc because the splintering will get worse over time and they will be unplayable.

    Its was a fault in manufacture, the ‘disc wash’ before the lacquer coating was applied was performed with ‘hard water’

    The water supply in the Blackburn area is ‘Hard Water’ and did not flush all the pre-lacquer process contaminants away and the product should have been recalled. (How do you put a recall notice upon a estimated 5 million CDs)

    I tried returning my Status Quo, Slade and Elton John UK pressed discs that were affected to the PDO London HQ but was told to seek a refund from the retailer, this was back in 1998.

    If you have a vast number of PDO pressed discs that do not play, why not try sending them back to PDO, if enough people return their faulty discs to PDO something may get done but as always your purchase contract was with the retailer not PDO.

  • Mar 23,2017 at 1:14 pm

    I always look after my Cds LPs and Singles I even have music tapes,I never heard of disc rot,perhaps I been lucky or just treat them right,I know that some bought discs do not record properly I have had that trouble,but otherwise if a Cd does not play when it has before I clean it well and clean the laser eye,it normally cures the problem.

  • Mar 23,2017 at 1:33 am

    Disc rot has affected a few of my CD’s. It certainly hasn’t impacted them at all ;-)

  • Mar 22,2017 at 9:11 pm

    Yep, I have known about this for a long time. All of the discs I had that were affected were manufactured by PDO at their UK plant prior to about 1994. I contacted Philips and they replaced a great number of them (they stopped offering replacements 15 or so years ago, but you can always ask), but only about two thirds of the ones I had that were affected. They said they would replace the remainder, but I would have to ship them those discs first because they were ‘not aware they were affected’. As I did not want to ship my discs and have them go missing, and as a few of the ones they replaced were replaced with copies that were also showing signs of the issue, I declined to send them those discs. Surprisingly, even my worst/most affected discs (a couple were dark bronze on top and almost transparent when held to a light) were still readable in my PC as well as playable. So, I purchased some Archival Gold CD-Rs by Delkin Devices (archival quality CD-Rs supposed to be rated at 300 years) and made copies. Needless to day, with a large collection I was pretty freaked out, but after a lot of research (I was able to find several tests that had been performed by different manufacturers to simulate long term storage in various conditions), I came to my own conclusion that most of my original discs should last 70+ years as I store them always in their cases, indoors, in a temperature controlled environment. So far, so good; I recently ripped a large number of 30-ish year old CDs to stream in my home, and they seem to be doing fine (even the PDO discs I have that are affected seem to have stabilized, but I wouldn’t bet on them reading very well in all players). I also clmsoled myself with the fact that the CD data is actually encoded in the polycarbonate substrate; the aluminum is only there to reflect light. So, technically, the data will likely remain on the discs long after the aluminum has oxidized beyond any reflectivity, and our great-great-grandchildren will be able to revive our old collections by somehow removing the upper laminate and oxide and applying a nice layer of gold. ;)

  • Mar 22,2017 at 6:55 pm

    Funny that this article was highlighted in the monthly email newsletter today…I discovered some horrid disc rot on two import, out-of-print NIN CDs: March of the Pigs pt. 1 and Closer to God pt. 1. So very disappointing :(

  • KJX
    Feb 10,2017 at 9:32 am

    Any word on CDRs? Many musicians burned many CDs of original music. Many also transferred those to computer, but guessing some original music could disappear

  • Feb 9,2017 at 1:28 am

    Of my nearly 1000 music CD library and close to 1000 Karaoke CD+G, most of the disc rot that I suffered were discs that the now debunked Sound Choice used to press their songs on and almost all were pressed after 1994. I don’t which brand of discs they used but it was an issue. I have many audio CD’s that are over 30 years old that still play great today. Though I tend to stack my discs once in a while the key is keeping them from spinning on themselves and a controlled environment.

  • Feb 8,2017 at 7:17 pm

    Disc rot is mainly an issue associated with PDO, a CD manufacturer that originally made discs without the correct layers of chemicals to protect the disc from oxidation. It was discovered c1993, so the problem is really only relevant to CDs manufactured by the company before then as all their discs following this have been made correctly. And with many of them being repressed, this is not something to worry about too much. Discs manufactured after 1993 and all those made by other CD manufacturers before then (mainly Disctronics) still sound as good as the day they were pressed. Once again, a fluffy article about nothing, wrapped up in blatently obvious common sense.

  • Feb 8,2017 at 7:15 pm

    Yep. Known about this issue for years. If I remember correctly there were a stack of early discs from the mid eighties, which were manufactured in one plant, without a complete lacquer coating – it didn’t go completely round the edges? So they would corrode from the edge. This was a design flaw at a particular manufacturing plant. Fairly sure the manufacturer initially denied there was an issue and then eventually had to admit because of overwhelming evidence.

    There was also some discussion in the late eighties / early nineties about some jewel case inserts being made from materials which emitted chemicals which would speed up corrosion if the lacquer was flawed / damaged.

    I’ve been quite lucky so far. I’ve only got two unplayable discs due to corrosion as far as I know – a first pressing of U2’s Joshua Tree from 1987 and a reissue copy of FGTH’s Welcome To The Pleasure Dome (year unknown). Out of approx 3000 CDs I reckon this is pretty good going.

    My strategy, in addition to the tips in the blog, is to always rip every disc as soon as I receive it using Exact Audio Copy with AccurateRip enabled and to keep the rips on both my PC and a backup NAS (with RAID enabled) in another room. Still not an absolute guarantee, but pretty good I reckon:)

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