The place where I work has a dining room where we get large styrofoam cups to drink from. I usually drink ice water and have noticed something unusual. After filling a cup with ice and water and letting it sit for awhile, it sweats. This part I understand, as it is the difference in temp between the cup and the room air. However what the cup sweats is blue, like Listerine. Why? Is this a chemical residue from the styrofoam? Is it safe? Am I drinking this?
Thanks.