TORONTO - It helps answer the call of nature and it cleans up afterwards -- all for the price of a quarter.

Welcome to Toronto's first automated public toilet, opened by city officials Wednesday at a waterfront location. It's expected there will eventually be 20 such toilets in various locations across the city.

Users must insert a quarter or a token and will then have 20 minutes of privacy in the automated outhouse. The time remaining is counted down by a three-step audible warning and a blinking light.

Once the person exits, the unit seals itself and begins a cleaning cycle.

City officials say sensors in the unit will be able to detect if anyone remains in the unit past the 20-minute mark, and help could be summoned in the case of an emergency.

All of the units will be wheelchair accessible and climate controlled, and Mayor David Miller said they will "provide comfort and convenience" for both residents and visitors.

The toilets are part of a larger deal with Astral Media Outdoor to provide the city with about 25,000 new pieces of street furniture over the next 20 years. The furniture includes co-ordinated benches, bike racks, litter and recycling bins and transit shelters. Astral will in turn profit from advertising on the shelters.

Officials say units will be regularly maintained and service people will check them three times a day.

Many large cities outside Canada have been using such public toilets for years. Those behind Toronto's new privy consulted with a number of those cities to find out which design would work best.

"The unit we have selected will offer a clean and secure indoor environment and is equipped to operate year round," said Luc Sabbatini, president of Astral Media Outdoor.

Among the cities scrutinized was Seattle, whose experience with the public loos was less than favourable. The free-of-charge units were reportedly taken over by prostitutes and drug addicts.

After spending four years and several million dollars on the toilets, the U.S. city pulled the plug on the project and had the units removed.

However, Toronto's units will be placed in high-traffic areas and officials say the pay-for-use model should reduce undesirable activities.