V-5 Alley Viper and V-19 Storm Shadow question.

[4 cobra]

I just got a box of Joes out of storage that's been in there for a few Years, and they were in a cardboard box. And I had a few of the V-5 Alley Vipers in the box with the rest of the figures, and I noticed they had Yellowed on their legs. And some were worse than others, but all 4 were Yellowed to some extent. There was also 2 of those V-19 Comic Pack Storm Shadow figures, and they have Yellowed a little. I've known about the V-1 Storm Shadow & other Joes parts that have Yellowed, but the newer Figures I didn't know they would Yellow. But seeing how these early to mid 2000 figures are getting up there in age I guess it was going to happen. I've heard some people say the sun is the cause of the Yellowing but these were stored in darkness with no light, so I don't know. I also read somewhere that the older Joes had some type of fire retardant chemical put into the plastic mix, and that's what causes the chemical reaction in the plastic. Anyway I was just wondering if anybody else has seen this with the newer Joes including the V-5 Alley Viper & V-19 Storm Shadow in particular.

[Alchemist]

My Storm Shadow v19 doesn’t look as white as when I got him, but I’m just not sure on that one. I do, however, have one modern figure that has definitely discolored, which is Cobra Commander v15 from 2003. The odd thing about the figure is that only his front chest piece and inner leg pieces discolored. I have seen vintage figures discolor only in certain parts like this, as well. I used to own a v1 Storm Shadow that just had half of a leg yellow. I remember seeing a picture of a MOC one where just his head had yellowed. While I’m sure that things like sunlight and humidity can cause discoloration, some figures just might be more prone to discolor due to the plastic that they were made from. And, in some cases, might discolor regardless of how well they’re stored.

[4 cobra]

I've also noticed that some Joe Figures will Yellow on one part, and not the other. This is the way my Alley Vipers look, one side of the leg has Yellowed & the other side is fine. There's a set of 3 V-5 Alley Vipers up on e-Bay right now, and you can see what I'm talking about. On the 1st one his right leg is Yellowed, and his left leg looks fine.
And from what I was talking about with the Fire retardant Chemicals they add to the plastic mix, the guy said that some plastic might have more in it than other parts because of it not getting mixed in all the way. And that's why some parts Yellow differently, but who knows that's just another theory in a long line of theories on this issue..

[PJDonnell]

Yellowing isn't just caused by exposure to the sun. The chemical make-up of the plastic itself can cause yellowing over time. Some plastics are even susceptible to yellowing from exposure to our skin oils.