WASHINGTON (CNN) -- Congressional opponents of peanut-free zones on airplanes succeeded in requiring a scientific study of peanut allergies before any more federal money is spent on developing the rule.

Language inserted into the $500-billion spending bill that Congress approved and President Clinton signed Wednesday prevents the Department of Transportation from spending any federal funds on peanut-free zones until Congress receives a "peer-reviewed scientific study."

The DOT proposed in August that airlines set aside at least a one-row buffer for people with medical proof that they have severe peanut allergies. Groups such as the Food Allergy Network said even trace amounts of peanuts can cause sufferers life-threatening problems.

The DOT proposal was jeered by nutlovers and taken as a sign of government run amok. Lawmakers from peanut-producing states said they were not convinced that small airborne peanut particles could create a problem for allergy sufferers.

Alabama Republican Sen. Richard Shelby said the proposal was not based on scientific evidence. "These guidelines represent why so many people have come to resent and distrust government," he said.

Peanut farmers feared the nut-free zones rule would lead airlines to completely drop peanuts from their flight menus instead of dealing with the hassle of limiting them on some flights.

Reuters contributed to this report.