I'll toss em just to be safe it's only two outta 20. Iv just never seen this before. Wasn't sure if it was a kind of bruising or something. It's only in that one spot. I took em outside an opened em an its on it that one spot. Didn't seem it spread..Hmm.. ? Haven't seen this contamination before either.. no clue what it is , but sorry to say you should probably toss them.. take no chances ..