Plastic bags and silica turned yellow in my ammo cans?

[John94z]

Hey guys. Long time lurker finally i had an issue pop up that promoted me to stop being lazy and finally register. I did various searches and came up with nothing of real use.
I had been shifting some ammo around in cans and noticed that in one of the cans which was packed years ago my silica beads were yellow and so were 2 ziplock bags i had in there. This struck me as pretty odd because the beads i have are just standard indicator beads that turn from blue to pink when they need to be recharged. Not yellow but for good measure i heated my oven to 250 and stuck them in there for a couple hours and while the indicator beads turned back to blue the other (normally clear) beads stayed yellow. I'm at a loss here. All i can assume is this is from a chemical off gas from the powder. (Its Centurion XM193 that i purchased in 2008) I keep my cans in good condition with no rust and i use alcohol to clean the inside when i purchase them to make sure i don't come up with any contamination issues. I live in west TX too which is pretty dry as it is i'm actually surprised the beads needed to be recharged. Oh and the cans have always been in stored in a room temperature environment. I took a couple photos and tried to use as much white contrasting as i could but the cell phone camera doesn't quite capture it on the bag.
ANY HELP IS APPRECIATED!
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[sevenhelmet]

Welcome to the forum!

Not sure why your silica would turn yellow, but the best guess I have would be the plastic broke down due to either something in the air such as oil residue on the ammo or acid in the paper if you packed it in the original boxes. Was it stored in a hot location by chance? About how long was it in storage? Plastic like that will yellow, but that's usually from the sun, in my experience. Are you 100% sure your ammo cans had good seals that didn't dry rot or leak?

As far as recharging silica goes, I've found I have to rotate silica packets once or twice in my cans before the humidity indicators stop indicating moisture, even with factory fresh ammo that seemed bone-dry. If it was packed for years, it just means the silica absorbed all it could from the air trapped in the can and whatever was in the ammo packaging (cardboard always has a tiny amount of moisture content). It's also a good way to evaluate the seal of the can itself. Pack 'em up, and re-check 'em after a couple of weeks. You can usually tell by then.

How about the ammo itself? Was it corroded at all? If not, then I wouldn't worry about it- get a fresh bag, some fresh silica, and re-seal 'em up.

[John94z]

Thank you and you brought up something i forgot to mention in the OP which was the climate. It has always been at room temperature. I edited the post to add that. I didn't store them in boxes. This ammo was bulk purchased and went into the can like that. I did use the thick plastic bags they came in to line the cans which is something i started doing for all of my cans now. There is no discoloration on those bags. Just the 2 little ziplock bags containing some diff ammo in small quantities. These cans have been packed since 2008 with minimal openings and the gaskets are serviceable with no rot. The silica was last changed in 2011. As far as leaks go, that's a good question im wondering because i live in the desert and i use a pretty good amount of silica in each can. I was shocked to see the indicator beads no longer blue.
The ammo doesn't have any apparent signs of damage i plan to do some tests with this particular batch at the range but itll take me a little bit to get down there. Its kind of alarming because i've never seen anything like this before.