It's not just blast effects that are a problem, any soft plastic MAY do the same thing to hard plastic it's near, especially if that plastic is painted, for some reason. The soft fins on Combiner Wars airplanes of all sorts (and POTP ones too like the Decepticon Powermasters) can do it. One of the reasons I was iffy on the soft plastic on the TFSS stuff and Ghostbusters as I could feel a tackiness where fins or hoses would touch plastic with paint. Nothing ever went bad, but that's because I kept things moving to avoid contact. Way too much trouble, and so when my fiascoes happened I was not that upset when I had to sell them. I am still very iffy on any Transformer with soft rubbery parts for that reason (Titans Return Weirdwolf and Mindwipe both had their softer plastic eat the surrounding stuff leading to hinges crumbling). I seriously considered the new Aerialbots and Fallen, but am holding both for financial reasons and also wanting to know if the fins/weapons are the same flexible stuff. It's even worse when the rubber part itself is painted. Then it can get sticky without touching ANYTHING...
Keep in mind this isn't limited to Transformers. I've seen old Masters of the Universe do the same thing with heads, legs, O-rings, etc. I've even seen an old eraser eat its way into a plastic desk drawer, looked like someone had spilled acid around a very old dry crumbly pink square, or a rubber snake dissolve the inside of a tupperware storage box.