Bubbling damaging game cartridges

Hi there. I’m not a native English speaker so sorry about any grammar mistakes.

I collect videogames since 1995, at least. I have LOADS of NES, SNES, Game Boy, Genesis/Mega Drive cartridges, among other systems.

A couple years ago I discovered that a dozen or so of my Game Boy cartridges felt humid to the touch and were full of bubbles under the plastic.

I panicked and started googling right away. Apparently it happened to a few people, but not that many, and there was no conclusion about the “why”. Humidity, heat, plastic containers were all possible reasons. One YouTuber came to the conclusion that it was gas fumes that ruined his games.

A few months later I discovered the same problem on some of my SNES games. In this case, mostly the games released between 91 and 92, and always the back of the shell, never the front.

I did what I could to reduce humidity and kept my windows closed so there’s less carbon monoxide inside (I live close to the street).

Well, today I have inspected my NES games and something close to thirty of them are infested with those bubbles. Contrary to the SNES carts, the bubbling only occur in the front piece of the shell, which means the labels end up with bubbles beneath them. It’s not pretty.

One of the games affected is my beloved Castlevania 3 cart that I first played in 92 and ended up buying later in 97. That one hurted.

The thing that amazes me is that it affects NES/SNES and grey GB games, not some obscure Channel F cartridges, and yet there’s no definitive explanation.

As for me, I’m considering selling it all. Since no one seems to know why, the pessimist in me thinks it will only be a matter of time before a really valuable game such as Harvest Moon or Earthbound is affected as well.

I’m an anxious person, and as much as the thought of selling my very dear games hurts me, this is making me too angry and sad.

I’ll post some pictures of the damage bellow.


I’ve seen this before but never really thought about it - I always considered it just a side effect of poor quality plastic and age - like how all plastic hucard sleeves eventually get sticky, and many labels come off because they stick to the sleeve.

I have a cheap bootleg genesis game from India and it’s not bubbling, but it is slowly deforming over time. Hard to see but it’s there.

I suspect it will eventually happen to all games that actually get use.

On the other hand, I wonder - are you completely sure the bubbles weren’t there from the start? Bubbles get introduced with improper molding, and maybe it’s possible the gasses in there expand over time??

Certainly interesting to investigate!


No, this is most definitely new.

Something that I forgot to mention is that these bubbles, when they are big (3 or 4mm), can be pushed with a fingernail and some pressure. They are soft. Sometimes they burst and some liquid seeps.

It definitely feels like it’s the ABS plastic becoming unstable.


I’ve seen this before as well! I’ll have to dig and find another example.


Some additional pictures:

Only the front part of the shell is damaged in NES games. The back looks like it was made today.

As for the SNES games, it’s the contrary.

Sometimes these bubbles go away on their own, and this is what remains in their place - these white spots that look like acid drips.

For now this is all know.


I’m not a native English speaker so sorry about any grammar mistakes.

Do you perhaps live in a more humid climate ? That could explain the problem. There’s also the matter of where you keep those cartridges. Any exposure to sunlight will fuck them up in the long term. Even if light does not hit them directly, being on a display shelf in a room with a window can degrade plastic rapidly.


This is a major bummer. But if the games still work that’s what is important.

Semi related, I bought a cartridge recently that the label had peeled off almost completely and the adhesive had stuck to a bunch of dirt and grime. I used an adhesive solvent to remove the old gummed up adhesive and then a glue stick to stick it back on. It’s not perfect but it worked pretty well


I’ve seen the Elliot Coll video you might be talking about where he discovered a bunch of carts in a sterilite tub in his attic were covered in the bubbles, or something.

I don’t own a ton of cart-based games but I live in a pretty humid non-tropical climate and I think all my games are fine.


Hmm this is a mystery. My cartridges are in pretty good shape and I haven’t been taking as good of care of them as I should. It gets pretty humid here at least 1/3 of the year. Could the bubbles be where they were handled or held?


Answering everyone:

@buy-frank-lewd-mags: I do, it’s pretty humid here, but not particularly hot for most of the year, and I kept them out of sunlight as well.

@Sun_Crypt Yeah, they work. The PCBs are intact, but it’s hard to forget that I’m losing money.

@DaveedNoo No, most of the bubbles are inside the shells, where there’s almost no handling. Also, there’s usually a pattern to the bubbling. Let me show you:

Notice that they start around that plastic bump and circle toward the edges.

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I was talking to a friend this morning and we were thinking about the possibilities.

If carbon monoxide did this, then almost everyone would see some damage in their games. Same thing about humidity or indirect sunlight.

We thought about the cause being more than one factor, and he asked me about vapors caused by cleaning products.

The first time I noticed this bubbling was around September or October 2022. Earlier that year, in February, a friend of mine recommended me an anti-mold product called Sanol A7 (I live in Brazil btw).

I was having some trouble with humidity and a wall was always with some mold. I used this Sanol a LOT during that year.

Today I was reading the product’s label. Seems that its main ingredient is benzalkonium chloride.

I just did something, then. Got myself a ziplock bag and stored one of those shells along with some of the product to create a little greenhouse effect. Let’s see if the situation gets noticeably worse in the following days. I’ll let you know.

Anyway, just in case, keep your games away from chemicals.


Hey! i also live in Brazil!
A few tips from my collection keeping:
i put everything on ziplocks with silica gel sachets and every few months i renew it.
If you own gamecube games i also suggest putting inside their cases since it has a hole.
Last year i got rid of 90% of my collection but i kept gifts so i still maintain them clean and organized.

I live near sierras (about 3km) so it can get humid at night. Do you perhaps live in the coast? if so, i strongly suggest you use anti-mould / anti-moisture stuff.
Sanol is good but beware of residues.
I got a ps3 from a friend that lives in recife, it was all rusty and stopped working really fast :confused:

If you need any tips, hmu!


My ziplock experiment didn’t result in anything, unfortunately.

I ended up buying some new furniture so I could store my games inside drawers instead of plastic boxes. Also they will now be protected from indirect sunlight and farther from carbon monoxide, as they’re now in another room.

A few months from now I’ll resurrect this post so I can tell you guys what did become of them.


I’m still trying to find the ideal cartridge storage solution and dressers keep seeming like the thing to do… trying to find one that will fit snes, nes, and genesis (mostly genesis) is quite a task though.

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I did the math (how many square meters I needed - almost two) and went to a local shop that sells used furniture. I recommend it - old wardrobes and cabinets are usually made of better wood and are cheaper.

This is the one I bought:


Sakurai just flexed a bit of his collection:


Oh yeah, I’ve watched it while thinking “he should upgrade to wood” the whole time. :grinning:

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