Fairfax County's unique new code of business and consumer ehtics was landed yesterday by White House consumer adviser Esther Peterson as "a good way to get started" but not a "panacea" that will solve all problems that exist in relations between companies and their customers.

At a Capitol Hill news conference called to announce the new code, Peterson renewed her plea for support of a federal Agency for Consumer Protection.

Many problems simply cannot be solved by business concerns at the local level, to which the Fairfax code is limited, she said.

Larry V. Fowler, who heads the Fairfax consumer commission, recalled yesterday that efforts to draft a code of business ethics in his county began with a haircut. A former head of the commission was shocked to discover - after his hair was cut - the high cost, Fowler said. "He suggested a law requiring barbers to post their products."

What emerged, he said, was a code much stronger than local law - one which requires that firms not block cash registers, adhere to cost estimates, work against illegal activity in their industries and protest to manufacturers about shoddy goods.

"We do not intend to let our code by issued and forgotten," Fowler added. He was joined at the news conference by John F. Herrity, chairman of the county board of supervisors; chamber consumer committee head Florence Townsend and Rep. Herbert E. Harris II (D-Va.).