After four months of research that sorted through almost 1,200 treatment proposals, scientists looking for a chemical solution to the oil spill have essentially come to a dead end, leaving beach workers to continue with increasingly ineffective hotwater washing, said Carl Lautenberger of the Environmental Protection Agency.

A large scale test done on Smith Island last week showed the latest formulation of Corexit to be generally harmless to marine life, but of marginal benefit in freeing oil clinging to rocks, Lautenberger said.

Given the results of the tests, Lautenberger said, scientists from the resource agencies represented on the R&D committee decided it didn't make much sense to pour the kerosenebased chemical on Alaska beaches.

"There just isn't enough of a gain in efficiency," Lautenberger said. "It's not that there's so much of a red flag on toxicology."

Corexit 9580MS was one of about 10 chemicals on which intensive study was begun in June, two months after the oil tanker Exxon Valdez hit Bligh Reef and spilled 11 million gallons of oil into Alaska waters.

As late as last week, David Kennedy, spill response program manager for NOAA, was hopeful that scientists had found in 9580MS a potential remedy for beaches slathered with the now tarlike crude. Present beachcleaning techniques are removing only about 20 to 30 percent of the oil, Kennedy admitted.

Exxon chemists, he said, had tinkered with an old chemical dispersant to come up with a new formula for a beach cleaner that appeared to show real potential in smallscale tests. Coast Guard Vice Adm. Clyde Robbins, the onscene coordinator for the spill cleanup, was anxious to give the chemical a try.

Not much else was working, he said.

"The oil is tenacious," Robbins said. "It sticks to everything it touches. Breaking it free so that it can be collected is almost impossible. When coldwater washing was ineffective, (beach cleanup crews) turned to hot water, using huge flushing systems supported by barges. When the water is hot, and when supported by hand wands and highpressure water from hand hoses, it loosens some of the oil, but it also washes oil deeper down into the substrate.

"In addition, there is some concern that the heavy washing is also moving the sediments to below the tide level, possibly adding more to the environmental damage done by this spill."

"We're beginning to wonder what price we may be paying (for hotwater, high-pressure washing," Kennedy added. "Certainly, we ought to be able to come up with something that will do better."

Scientists tried to find a better solution through chemistry. They wanted a chemical that would dissolve the oil clinging to the rocks, then bond to it to float the oil to the surface.

They figured a light spraying of Corexit 9580MS would work. The plan was to put it on the rocks with backpack sprayers and then wash it off with water. Booms positioned off the beaches would catch the mixture of Corexit and oil washing into the ocean, and oil skimmers would suck it up.

That would be much better than the hotwater washing, a technique so marginally effective Robbins compared it to washing one's hands without soap.

As it turned out, the Corexit wash wasn't much more effective.

"It (Corexit) simply didn't seem to do what it was designed to do," said Eric Jorgensen, an attorney for the Sierra Club Legal Defense Fund. The environmental group opposed the use of Corexit, and Jorgensen praised agency scientists for saying no.

"These are some tough judgment calls," he said. "I think there's a lot of pressure coming from Exxon. I think there's a lot of pressure coming from perceptions of what the public wants done, what the administration wants done."

People are concerned about making the beaches look their best when they should be focusing on making them function their best, he said.

"It's a tradeoff."

Scientists have known that for decades, and they have been debating the use of chemical oil cleaners and dispersants at least as long.

Dozens of studies disagree on whether the chemicals produced by Exxon, British Petroleum, Arco and other companies are good or bad.

Many studies conclude the chemicals are useful in breaking up oil slicks over deep waters and preventing the kind of catastrophe that occurs when oil ends up on beaches, as it did in Alaska. But once the oil strikes shore, the studies diverge.

Some conclude that chemicals get the oil off the beaches, allowing it to quickly disperse into the water column with minimal influence on marine life.

Other studies say the chemicals leave the oil lingering in the water column with serious implications for marine life.

Some scientists argue that putting oil in the water makes it easier for microrganisms to attack and degrade it. Other scientists argue that oil left on the beach will fairly quickly turn into an environmentally benign asphalt.

Picking which course to follow is a guess.

"If I sound cautious, it's because I am," said Alaska Commissioner of Environmental Conservation Dennis Kelso. "Any chemical treatment . . . carries risks. Just as we would not continue hosing down a beach until everything was clean, but dead, neither would we trade clean rocks for poisoned water."

Chemicals tested in the past have a hard time passing that test.

Canadian researcher Peter Wells in 1984 concluded that part of the problem with oil dispersants is that their toxicity appears to be linked to their effectiveness: Effective dispersants are too toxic, and nontoxic dispersants are ineffective.

"Newer dispersants like Corexit 9527 (another Exxon formulation) are much less toxic than the dispersants used in the 1960s," Wells said, "but even these new dispersants have adverse effects on biological processes."

Lautenberger questions why more wasn't done to study and test chemicals in the five years before the Exxon spill.

"What in the world are we doing testing this stuff now?" Robbins asks.

There is now one month until Exxon shuts down for the winter. Kennedy is pessimistic the company can get all of Alaska's beaches treated by then without better tools for cleaning.

"Shoreline treatment rates so far have averaged a little over a mile per day," he said last week. "In order to reach the fall target date, the treatment rate would have to increase to four miles per day."

"If there was some kind of silver bullet, I wish somebody would pass it along," he said.