With all the talk about eliminating trans fats at U.S. eateries, one company is focused not just on what's in the fry oil but also how it gets into the fryer.

Minneapolis-based Restaurant Technologies Inc. opened a Denver depot in October 2006 to serve a growing number of restaurants attracted to RTI's closed delivery system because it means less handling of oil for them.

RTI installs two tanks that closely resemble hot-water heaters at restaurants. One tank holds the new oil; the other is home to the used stuff. Periodically, big tanker trucks pump out the old and pump in the new. Customers pay for the oil and the service.

Old oil ends up in a tank back at the depot, where it eventually is claimed and recycled by another company, said Matt Trembley, general manager of the Denver depot.

"It's cleaner for the restaurants because they get rid of the rendering tanks and the spills," he said.

Nationally, RTI counts McDonald's as a large client. The burger and fries giant named RTI an approved vendor for the frying oil, which means franchisees can opt to switch to the company.

Colorado franchisee Bob Charles was skeptical because the system adds about $4 or $5 a day to his costs. Still, he was swayed and installed the system in his Westminster store last November, he said.

Now, he says, the tanks are going in at a few of his Longmont stores as well.

The added cost is worth it, he said, because the system keeps things cleaner and RTI carts away the used oil for recycling instead of Charles having to hire someone else to do that.

Most important, he said, the closed system is better from a safety and insurance perspective because workers run a lower risk of burns from hot oil.

The Denver depot is the 36th for the company, which has inked deals with 84 Colorado restaurants, Trembley said.

RTI launched a decade ago in Minnesota, founded by a group of engineers who had previously worked to create a CO2 delivery system for fountain soda at a company called Valley Engineering, said RTI Chief Executive Officer Jeff Kiesel.

Nationally, it has 14,000 customers and 600 employees, and plans eventually to add up to nine new markets, Kiesel said.

While the focus is on the delivery, RTI also is paying attention to a growing clamor from customers for trans-fat-free oil for frying and is selling an increasing amount of proprietary soy and canola oils, he said.

In Denver, trans-fat-free oils sit in squat barrels, dwarfed by the giant 20,000-pound tanks of oils that most customers still order. But that's changing.

"It's definitely a hot-button issue because of legislation in other states," Trembley said. "It's a matter of time - the demand is growing."

forgrievej@RockyMountainNews.com or 303-954-5191