Um, What’s That Burning Smell?

We’ve talked about Starbucks many times on the little dish, sometimes in their favor (celebrating the great caramel chai discovery, or the time I made a badass cake) and sometimes against (hooray for the underdog!) This time it’s different. This time, it’s in the interest of public safety. Yeah, you heard me.
Here’s the deal: I’m a slow sipper. Usually halfway through my cup of coffee, I have to warm it quickly in the microwave. Thirty to thirty-five seconds in any standard microwave and it’s practically like the first sip all over again. I’ve done it a hundred times. Earlier this week, I noticed a strange burning smell as I warmed my latte at work. I thought it was only a little weird, mostly because people cook ungodly things, singe popcorn, and so on in that machine,
Then, two days later, it happened again. I inspected my cup and THERE! ON THE BOTTOM OF MY CUP! A SINGE MARK. Today, it happened again. There was a burn mark in the exact same spot. Thirty seconds and no more, in a standard microwave and we’ve got a (likely carcinogenic) fire hazard! It could be some new cheap plastic or glue they’re using on the rim; it could be some metallic manufacturing residue. I just know that it’s potentially dangerous…and weird. I’ll have to run some more tests to be a good scientist, keeping track of what stores the cups came from, what microwave was used, etc. to be really sure of what’s going on, but I can tell you right now, it’s pretty suspicious.
Suspicious? That something burns in a microwave?
Aside from being a jerk to you, I just wanted to point out that I’ve had this happen with many cups, not just Starbucks, and not just recently.
Yes my Starbucks cup burns. It is only the Starbucks cup – no other paper cup has this problem. It does not appear at the seam so I am guessing that there is a microchip in there. Possibly inventory control? I wil dissect my cup and see.
I have noticed the same with Starbucks paper cups on numerous occations but sometimes it doesn’t happen. Always at the same place you showed. At first I thought it might be because they were using recycled paper/cardboard and that there might be small amounts of tinfoil or some metal residue that gets mixed in with recycled paper.