CHICAGO • The trash can is overflowing, the floor is a mess and raising the toilet lid is a source of dread. Even the hardiest frequent fliers turn into germophobes hours into a long-range trip.

Boeing is preparing a solution: a self-cleaning toilet. The United States plane-maker says it has found a way to use ultraviolet light to kill 99.99 per cent of germs in jetliner toilets, disinfect all surfaces after every use in three seconds and keep the restroom from becoming a petri dish.

Lavatories that constantly tidy themselves at 9,100m above sea level could help slow the spread of infectious diseases borne by passengers jetting between continents, said Mr George Hamlin, an aviation consultant.

The invention could also reduce airlines' maintenance bills if it does not involve many moving parts, he said.

Airbus Group is working on a similar concept.

"If it's a reasonable cost, I could see this becoming widespread," Mr Hamlin said of Boeing's new product.

The concept offers a new twist on the old aviator saying, "If it ain't Boeing, I ain't going", aviation consultant Robert Mann said by e-mail.

"Boeing should ground-test these in big-city public facilities to develop some street cred," he said.

Boeing's lavatory prototype uses a type of ultraviolet light, different from the rays in tanning beds, that does not harm humans. Activated only when the airliner toilet is not in use, the lights flood touch surfaces such as the toilet seat, sink and countertop.

"We're trying to alleviate the anxiety we all face when using a restroom that gets a workout during a flight," Ms Jeanne Yu, director of environmental performance for Boeing's commercial airplanes division, said in a statement.

Airbus is working on its own improvements for jetliner bathrooms, according to Mr Ingo Wuggetzer, the European company's vice-president of marketing.

"Airbus is developing 'touchless' technologies for our future lavs and we will also include 'anti-bacterial' surfaces as an upcoming lav feature," he said.

"Moreover, as well as improving lav hygiene, the ambience and overall freshness will be noticeably enhanced. So, overall, Airbus is set to significantly raise the bar on the passengers' experience of using an in-flight lav."

Boeing has filed a patent for the concept, which it says can minimise the growth and potential transmission of micro-organisms. The sanitising even helps rid a toilet of odours.

It also operates without being touched. The cleaning system would lift and close the toilet seat by itself so that all surfaces are exposed during the cleaning cycle, according to Boeing.

Other perks for those worried about germs: a hands-free faucet, soap dispenser, trash flap, toilet lid and hand dryer. The plane-maker is also studying a hands-free door latch and vacuum vent system for floor spillage.

Boeing's concept is a finalist for a Crystal Cabin Award that will be announced at the Aircraft Interiors Expo in Hamburg, Germany, on April 5.

The potential benefits are not just in the bathroom. The self-cleaning concept could also help airlines save money on costly repairs, Mr Mann said.

Toilets "are notoriously difficult to keep to high standards, which shows up as odours that cannot be controlled and eventually, corrosion to structures adjoining the lav module", such as floor beams and fuselage stringers, Mr Mann said. "It really would be a maintenance cost savings too."

BLOOMBERG