TBHQ tetra butyl hydro quinone...I think that's what it was, let me check. Nope, been a long time...it's tertiary butylhydroquinone. I called the state agriculture agency in the mid 90s when I found TBHQ on the ingredients of a bag of chips. Might have been Doritos. A lab guy said it was a food preservative. Didn't sound too appetizing.