Though the Department of Transportation said it would consider whether peanuts should be banned from airplanes, it recently discovered that it isn't allowed to issue peanut restrictions thanks to a 12-year-old law. It said in a statement:

"The Department is prohibited by law from restricting the serving of peanuts aboard aircraft unless a peer-reviewed study determines that serving of peanuts causes severe reactions among airline passengers. There has been no such peer-reviewed study, so we declined to take action at this time."

Some airlines have voluntarily stopped serving peanuts or created nut-free areas on flights, but Delta, American and several other airlines tell passengers they can't guarantee a peanut-free flight.

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