Distinctive?white seat covers in Shanghai's taxis will soon be a thing of the past as the city's cabbies replace them with PVC seats in dark colors.

Taxis in service will begin switching to PVC seats next year and new vehicles will also be fitted with imitation leather, officials with Dazhong, the city's leading taxi company, told Shanghai Daily yesterday.

Shanghai cabs started a trend of using white cloth seat covers, a practice that spread to other cities, including Beijing, an official said.

"In a decision by the industry authorities, new taxis will be fitted with PVC seats, which are easy to clean compared to the current cotton and sponge-covered seats," said Guan Lu, an official with Dazhong.

The operator claims the move is environmentally friendly as white fabric covers must be washed frequently.

Guan explained the change was inspired by the 3,000 Volkswagen World Expo taxis the authorities put into service in May, which were fitted with PVC seats.

"Drivers were still able to keep them clean while many passengers said they liked the comfortable leather-style seats," Guan said.

Some passengers have welcomed the initiative. "Giving up the white seat covers is a green practice. It saves water and reduces pollution from washing and whitening them. Besides, the PVC seats are more comfortable," said Iris Ruan, a local office worker.

"It's good news and better for mothers traveling with young children," said the mother of a two-year-old child. "I'll be able to wipe off shoe prints left by my child on the leather seats. At present, I always feel great pressure from cabbies who fear my son will dirty their covers."

Local cabbies are obliged to keep their seats clean, facing a 200-yuan (US$30) fine if the company receives a complaint about grimy covers.

Drivers can be forced to drive back to their depot to change seat covers several times a day.

According to a survey of cabbies, an estimated 18,000 tons of water is needed each month to wash the seat covers of the 40,000-plus cabs in Shanghai.

However, some passengers have raised hygiene concerns.

"Dark PVC seats may look clean, but long-time exposure to different riders increases sanitary risks," said frequent taxi user Cloe Lee.