(CBS/AP) Air travelers were handed new rules Sunday, given permission to carry small amounts of liquid nonprescription medicine onto a plane and instructed to remove their shoes during security checks.

The eased restrictions on medicine and the mandatory shoe removal were among several measures the Transportation Security Administration ordered Sunday in response to the thwarted terror plot in Britain involving U.S.-bound airplanes.

TSA had previously banned all liquid medications; now it will allow up to 4 ounces of liquid nonprescription medicine.

In other measures, TSA said it would let flyers carry on low blood sugar treatments including glucose gel for diabetics; solid lipstick; and baby food. But it said all aerosols are prohibited.

On Saturday, the TSA added mascara to the list of banned items, which includes baby teethers with gel or liquid inside, children's toys with gel inside and gel candles.

But CBS News' Tony Guida reports that some experts are saying airport screeners can confiscate all the mascara and milk shakes they can find, but still another on-board threat lurks. Aviation consultant Michael Boyd says cargo is vulnerable to terrorists as well.

Boyd calls cargo "a wide-open place where people can inject things into airplanes."

And Rep. Edward Markey, D-Ma., who sits on the House Select Committee on Homeland Security, says more than 20 percent of all air cargo in the United States travels on passenger flights, Guida reports.