The Transportation Security Administration has been shaking up its security screening policy at airports, last week ending a decades-old requirement to remove shoes.

Now, Kristi Noem, the homeland security secretary, is fueling growing speculation that limits on liquids could be axed next. For nearly two decades, the T.S.A. has restricted the quantities of liquids that travelers can bring through airport security checkpoints.

At a political conference hosted by The Hill and NewsNation in Washington on Wednesday, she addressed the possibility directly, saying that she was “questioning” the longstanding policy.

“So that may be the next big announcement, is what size your liquids need to be,” Ms. Noem said. “We have put in place in T.S.A. a multilayered screening process that allows us to change some of how we do security and screening.”

But how soon could liquid limits be lifted and what would this measure take? We spoke to several security screening experts to learn more.