An employee of All Nippon Airways Co. works at Narita international airport in Narita April 29, 2009. REUTERS/Issei Kato

TOKYO (Reuters) - Women flying Japan’s All Nippon Airways will have a toilet all to themselves from next month, with the airline designating one restroom on most international routes as female-only.

The airline said in a statement it was responding to “numerous requests for this service,” adding that the toilet would be located in the rear of the plane and be available to women passengers from all classes.

An airline official told Kyodo news agency that ANA decided to designate women-only lavatories based on a 2007 online survey in which 90 percent of the women polled said they found the idea attractive.

The official also said women do not like using shared toilets as men sometimes leave the seat up. She said demand for women-only toilets was especially high among passengers taking long flights.

Men would be allowed to use the lavatory only in emergencies or when there were very few female passengers on the flight, the ANA statement said.

South Korea’s Korean Air has been offering similar facilities and ANA rival Japan Airlines designates lavatories for priority use by women, the ANA official told Kyodo.

Toilet etiquette appears to be an important part of ANA’s policy -- the airline had previously asked passengers to use the lavatories before they board flights so as to reduce the overall weight of the plane, which would ultimately be better for the environment as it would mean less fuel usage.