Dressed in protective clothing and face masks, federal workers removed thousands of gallons of toxic chemicals today from an unlicensed dump described by the U.S. Environmental Protection Agency as among the worst in the nation.

By this evening some 300 barrels, 70 of them empty, had been hauled away from a storage area owned by Chemical Metal Industries Inc., a defunct metals reprocessing company. The site, located near the Baltimore-Washington Parkway in the Westport section of the city, was included in a list of the 115 most dangerous hazardous-waste dumps released today by EPA Administrator Ann Gorsuch.

The federal government plans to clean up the sites as part of the superfund approved last December by Congress, and the efforts begun here Thursday were the first in the Middle Atlantic region to be undertaken under the new program. One site in Washington -- in the Fort Lincoln area of Northeast -- was included in the EPA's list, but a spokesman for the D.C. Environmental Services Department said the nontoxic material there will be removed soon without the federal funds.

Two sites in Virginia were also included in the EPA list. One in Salem contains electroplating wastes that have caused contamination of groundwater. Another in Yorktown was used as a dump for fly ash.

The "emergency" cleanup here is expected to take nine days and cost $58,000. It will then take two or three months and additional funds to complete soil testing and purification if necessary, officials said. Several hundred plastic and metal 55-gallon drums, some leaking, and nine above-ground 5,000 gallon tanks are at the site. Labels indicate the containers hold various acidic and alkaline solutions, salts, cyanide and ammonia-bearing compounds.

The processing plant and the storage site are separated from each other by a block of row houses, inhabited largely by retirees who have complained about the place for years, to no avail. Neighbors told stories of chemical spills burning children and fumes so intense they could not stand to open their windows.

"I didn't know what junk was over there," said Margaret Davidson, in her tidy home two doors from the storage site, a former filling station surrounded by a cinder block wall. "Little children would put ladders up and go looking for baseballs," her husband, Roy, said.

Despite complaints to the city and several visits by the fire department, the Chemical Metals company continued to operate without the necessary permits, state and federal officials said. But during a routine inspection in August, a state inspector found the place abandoned and Maryland health officials applied to EPA for a superfund grant after determining the chemical did not pose an immediate danger.

The minority owner of the company is Jeanne B. Mandel, wife of former Maryland governor Marvin Mandel. Jeanne Mandel also described herself as an employe in court papers filed in a stockholders' suit. Helen Dorsey, her daughter, worked for the firm as a secretary and was a director as well, according to court papers and a former employe.

Court documents list Warren Stein as president and 40 percent shareholder of L & M Associates Inc., sole owner of Chemical Metals. Mandel is said to own 10 percent, with the rest owned by Lester Feit.

Feit, at one time a company vice president, sued Stein and Mandel last year, charging they "fraudulently and illegally and oppressively conspired to seize control" of the company from him. Feit alleged Stein took precious metals from the firm's vault "for his own use" and Mandel contracted for "unnecessary repairs."

The lawsuit charged that Stein and Mandel had "calculated to defraud Chemical Metals from its profits and ability to pay its creditors." Stein and Mandel denied the charges in court papers. None of the three principals could be reached today.

Another suit filed by a creditor in April for nearly $10,000 led to Chemical Metals being placed in receivership this summer. Richard Kind, a lawyer appointed to evaluate its assets and pay its creditors, said it appears the defunct firm owes "at least" $100,000 to 40 or 50 creditors.

The corporation and its owners may be liable for criminal penalties, too, under a state law carrying penalties of up to three years and of up to $25,000 for each day a hazardous-waste violation goes uncorrected.