DU.S. House lawmakers passed legislation late Wednesday that would give federal regulators the authority to set minimum standards for seat size and leg room on flights.

Tucked inside a 2,000-page funding bill is a provision that gives the Federal Aviation Administration a year to establish minimum pitch, width and length on airplane seats to ensure they are safe for passengers. The legislation, which funds the FAA for the next five years, passed 398-23 in the House and now goes to the Senate.

The proposed law is designed to ensure that what have become increasingly cramped planes can be evacuated quickly in an emergency. Current FAA rules require airlines to evacuate in 90 seconds or less.

That policy hasn't been updated significantly in almost two decades. Investigators at the Department of Transportation, which oversees the FAA, said in June that they plan to study whether the FAA is ensuring that today's more crowded aircraft meet federal evacuation standards.

Commercial airplane cabins have become more cramped as airlines fit more seats on board to increase profits and spread out costs among more travelers. Several carriers have reconfigured their planes to not only include more seats but also smaller lavatories in some cases.

Seat pitch, a proxy for legroom, on commercial airplanes measured about 35 inches in the middle of the 20th century, but that's now around 31 inches, according to SeatGuru. Some budget airlines, like Spirit, offer 28 inches of seat pitch.

In addition to less pitch, some airlines are adding more seats to their planes.

JetBlue is retrofitting some of its Airbus A320s, taking them from 150 seats to 162. American Airlines, the world's largest carrier, is bumping jets that had 181 or 187 seats up to 190, and jets with 160 seats up to 172.

"Safety should not take a back seat, especially a shrunken seat, to airline profits," Rep. Steve Cohen, D-Tenn., said in a statement after the bill passed the House. "Tightly cramped seating on aircraft is a safety issue, and will now be taken seriously. The SEAT Act will ensure that shrinking seats on airplanes are evaluated in the interest of the safety of the flying public."

American Airlines CEO Doug Parker said he welcomed any study of whether the carrier's seats pose any safety risk.

"We're certain [seat safety risk] isn't an issue at American Airlines today and any sort of study will bear that out," he told reporters at an airline industry conference earlier this week in Boston.

The bill also requires a government study of whether airlines' shrinking or reducing bathrooms in favor of more seats on board creates problems for passengers accessing lavatories.

Before going to vote, lawmakers scrapped a provision that would determine whether airline fees, such as those to change a travel date, are reasonable.

WATCH: It's not just your eyes. Airline seats really are getting smaller.