DENVER (CBS4) – Lawyers for King Soopers told a jury on Wednesday a man who claims his health was harmed by microwave popcorn did not disclose that he had been exposed to dangerous chemicals for years.

There was no disagreement that Wayne Watson had respiratory problems. The conflict is over how he got them. He is suing King Soopers and its parent companies claiming they should have warned him the butter flavoring, a compound called diacetyl, was dangerous.

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“Who would ever reasonably think that popping popcorn in your own home, no matter how it’s packaged or processed, would all of a sudden turn into an agent for toxic lung disease,” Watson told CBS4 in 2010.

But attorneys for the grocery chain told the jury Watson lied about his claim of how much microwave popcorn he consumed and when he used it. Instead they insist his health problems stem from his years working in carpet cleaning using dangerous chemicals.

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The doctor at National Jewish Hospital is a key witness in the case who diagnosed Watson with popcorn lung.

Wayne Watson outside of court on Wednesday (credit: CBS)

“(I asked) was he exposed to or was he around a lot of popcorn? And his jaw dropped and he asked me how I would possibly know that about him,” Dr. Ceclie Rose said.

Previously quality testers in popcorn factories had won or settled lawsuits worth millions of dollars after claiming health issues from inhaling the flavoring. Now a jury will be asked to decide if Watson, a consumer, could have inhaled too much popcorn flavoring, or an entirely different cause.

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Watson’s attorneys claimed there should have been a warning on the label. But lawyers for the supermarket chain responded saying they “might have well have warned that there are aliens popping out of the bags because there’s just as much support for that.”