The Pentagon's Eco-Leaders

The air-conditioning plant on an aircraft carrier is large enough to cool more than 1,200 normal-size homes. Tanks and fighter jets carry fire-suppression devices that save lives in combat.

But those cooling units have traditionally relied on chlorofluorocarbons (CFCs) and the fire-extinguishing systems on gases known as halons -- substances that are blamed for destroying the ozone layer.

In a big step, taken almost two decades ago, the Defense Department began to scrub those ozone-depleting substances out of its systems. It has been a sustained initiative, part of the increasing environmental awareness shown by the nation's military giant.

At the heart of the effort are three Defense employees and a contractor. They relied on basic science, small and large tests, and partnerships with chemical companies. They developed cost-effective alternatives to the harmful substances, which thin the ozone layer and allow more cancer-causing ultraviolet radiation to reach the Earth's surface.

The four were recently honored by the Environmental Protection Agency with "best-of-the-best awards" during a celebration of the 20th anniversary of the Montreal Protocol, an international treaty drawn up in response to the 1985 discovery of an "ozone hole" over Antarctica.

The Defense honorees were among the about 30 individuals and dozens of organizations given awards by the EPA and the United Nations Environmental Programme last month. The awards were especially important to the Defense honorees, who have helped develop an aggressive program to phase out the use of substances that damage the ozone layer without endangering the lives of military personnel.

"It is rare to see cooperation like this across government agencies and into the private sector," said Peter Mullenhard, a senior engineer at Science Applications International Corp., and one of the award winners. "It's a tremendous effort that took just a few people getting together."

Halons, in particular, had been exceptionally useful to the military. The nontoxic gas, for example, met a key combat requirement of the Army -- put out a vehicle fuel tank fire in a quarter of a second.

Steven McCormick, an award winner, led the effort at the Army Tank Automotive Research, Development and Engineering Command, to identify alternatives to halons. The Army now uses a half-dozen different firefighting agents in its vehicles as replacements for halons. McCormick's work led to a 60 percent reduction in annual halon use by the Army between 1992 and 2006.

Starting in 1999, the Army quit using halons in building new vehicles. Halons are still used in the crew compartments of Abrams tanks, Bradley fighting vehicles and an artillery supply vehicle, and the big challenge is to figure out technical and safety issues involved in retrofitting them, McCormick said.

Another award winner, Gregory Toms of the Naval Sea Systems Command, manages the Navy's overall ozone-depleting substances program. Electronic equipment, radars and electrical systems generate substantial heat on ships, and Toms oversaw the development of CFC-free upgrade kits that can be installed on ships in port for maintenance.

More than 75 percent of the Navy's air-conditioning and refrigeration plants on more than 250 ships have undergone the conversion. When the program is completed in 2014, it will have eliminated more than 500,000 pounds of ozone-destroying CFCs.