United Fiberglass Inc., under fire from its Woodbridge neighbors who allege that emissions from the plant have caused health problems, unexpectedly closed its plant last week.

According to former plant president Robert Bailie, the closing was caused in part by community pressure and mounting expenses stemming from state agency requirements for correcting air and water pollution violations.

Bailie, who said he has resigned as president of the firm as well as from its board of directors, said financial stress caused by the antipollution expenses, coupled with increased competition from the country's three leading insulation manufacturers, contributed to the closing of the plant. The plant began operating in January 1984.

"The citizens just wanted to close the plant," he said. "I don't believe pollution was a major concern. They just didn't want a plant back there [in a residential area]."

Some residents claim that eye irritation and breathing problems have improved since the plant closed disagree.

"You don't know how wonderful it is to take a breath of fresh air when you step outside in the morning," said Lucien Johnston, president of the Committee to Monitor Industry, which led the protest. "You don't appreciate such a thing until it's taken away from you." Johnston said that he used to experience nausea and lung irritation from breathing outside in the area.

Although a recent study by the state and county health departments found no conclusive evidence that plant emissions were causing respiratory or skin problems, the community continued to call on state agencies and local politicians for help in closing the plant.

"The action they took was very effective," said Bailie, who had also been president of the plant housed in the building before United Fiberglass bought it. "The corporate ship ran without a skipper for three months; there was somebody there from some agency every day -- and we had to stop everything and talk to them," he said. "During those months we were dealing with every federal, state and county agency that had any jurisdiction over us at the same time."

The concern now, residents said, is the pollutants left behind, which Bailie has promised will be cleaned up. According to county attorney John Foote, the State Water Control Board will seek an injunction to cleanse phenols from groundwater flowing from the plant into a nearby pond. The agency said the phenols have caused aquatic life in the pond to die.

Another concern, residents said, is that the plant's site, zoned for manufacturing, will be sold to a company that uses chemicals in its manufacturing process.

"We will push the county Board of Supervisors to pass laws that will preclude this happening again," said Trudy Simon, spokeswoman for the monitoring group. Foote said the county may be able to limit "noxious uses" of the plant site.

Former zoning administrator Sager Williams vested the land with a special use permit. Foote said, however, that if the land is not used within two years for the manufacture of goods that need the special permit, the special use is lost.

The county also is seeking an opinion from the state attorney general's office to determine if the county is bound by a zoning administrator's decision "forever," Foote said.