A biodegradable soy-based hydraulic fluid developed by U.S. Department of Agriculture scientists is now being used to operate the elevator system in the Statue of Liberty in New York City.

The work is part of ongoing research by scientists with USDA's Agricultural Research Service to develop new products from soybeans.

"Our scientists are continuing to find new uses for soybean-based products that go beyond everyday foods," said Edward B. Knipling, ARS administrator. "This is the latest example of how our scientists have found an alternative to petroleum-based lubricants."

Until recently, Lady Liberty's elevator ran on mineral oil formulations derived from petroleum. In February 2002, Jeff Marrazzo, the building and utilities foreman for the National Park Service on Liberty Island, N.Y., contacted Sevim Erhan, an ARS chemist in Peoria, Ill., about an idea for an environmentally friendly alternative.

Marrazzo had learned of Erhan and colleagues' development of printing inks and other vegetable oil-based products at the ARS National Center for Agricultural Utilization Research in Peoria. Marrazzo asked whether Erhan's team could bring that same expertise to bear in creating a hydraulic elevator fluid that would readily biodegrade in the environment, come from a renewable resource, be produced by an economical and non-polluting process, and meet industrial safety and performance standards.

Of the candidate vegetable oils, Erhan chose soy oil because of its low cost, chemical versatility and availability as a homegrown resource. At the ARS center's Food and Industrial Oil Research Unit, Erhan's team examined the chemical structure and function of mineral oil fluids and then used the information to devise their bio-based formulation using modified soy oil.

In tests, the soy-based hydraulic fluid worked as well as or better than the mineral oil products, particularly in terms of lubricity, biodegradability and reduced flammability.

Agri-Lube Inc. of Defiance, Ohio, scaled up production of the soy-based fluid, including a 1,000-gallon batch that's been used to operate Lady Liberty's elevator since Nov. 14, 2002. Agri-Lube is negotiating with ARS for licensing rights to commercially produce the soy-based fluid.

ARS is the USDA's chief in-house scientific research agency.