The General Services Administration yesterday ordered the National Archives to abandon immediately the old Langsburgh's department store as a warehouse for valuable documents until it can be determined whether the building can be made fire-safe.

At the same time, the archivist of the United States, James B. Rhoads, 50, announced his retirement. While one source said recent criticism of management of the Archives, which has prompted an investigation by the inspector general of GSA, "obviously weighed heavily" on Rhoads' surprise decision.

A GSA spokesman emphasized that there are "no criminal implications" to the investigaion, which was ordered last week by GSA Administrator Rowland G. Freeman III. The Archives is a division of GSA.

The GSA signed a 10-year lease for the use of three floors of the defunct department store on July 30, 1976, even though GSA's own fire prevention division had said the deteriorating structure posed "a hazard to those employed there and to the contents of the building."

Freeman said he and Rhoads jointly made a decision yesterday to close the Lansburgh building "in the interest of the public and employe safety."

The building was immediately barred to scholars who routinely carried out research there, and the eight Archives employes assigned there will be transferred at the end of work today.

Freeman said GSA would announce in about two weeks whether it will make the building secure for people and documents, or move to another location. The key factor, he said, will be cost.

Meanwhle, Freeman ordered increased building security, including a 24-hour guard and fire watch.

"We very much regret any inconvenience this may cause researchers and the public," Rhoads said, "but feel it was imperative to take the action we did."

GSA will weigh the cost of moving, and terminating it lease, with the cost of renovating the building, which is scheduled for demolition in five or six years as part of a redevelopment plan for Pennsylvania Avenue. The building occupies the block along E Street between 7th and 8th streets NW.

In accepting Rhoads' resignation "with deepest regret," Freeman called Rhoads "a distinguished achivist who is universally respected in his profession and by the public. He has brought substance, growth and improvement to the National Archives. He will be sorely missed."

Members of the inspector general's office went to the Archives last week to examine administrative practices at the agency, which is responsible for safeguarding more than three billion public documents, including the Constitution and Declaration of Independence. A source said he had been assured that the investigation "will not ease up" because of Rhoads' retirement.

Use of the Lansburgh building to store more than two million of those documents first was questioned by officials of the General Accounting Office at a congressional hearing in June, and renewed at a hearing Monday.

Rep. Richardson Prayer (D-N.C.), chairman of the House Subcommittee on Government Information, said he was "disturbed" that the Archives apparently had "no systematic plan" for either deciding what records to retain, or how to separate the money it gets by federal appropriations from donations to a trust fund.

A House Appropriations subcommittee raised similar questions last year about the Smithsonian Institution's use of trust funds and appropriated funds.

The investigation at the Archives is likely to center on reasons for what Preyer described as the "turnabout" by GSA on signing a lease for the Lansburgh property.

In June 1975, the regional office of GSA's public buildings service reported that its accident and fire prevention branch had determined that the building "did bot meet (archives) standards that require fire restrictive comstruction."

Holes between the floors also made it impossible to regulate temperature and humidity around the clock, controls that are vital to preserving old and crumbling documents, some that date back to 1789.

Preyer said "gaps" in the official records make it difficult to learn why GSA changed its position and signed a 10-year lease in 1976 with City Stores Co. for n annual rent of $171,600. City stores sold the property to the Pennsylvania Avenue Development Corp., a public agency on June 15, 1978, for $4.75 million .

Last October, Archives asked GSA to repair the heating, ventilating and air conditioning, but the work was never begun. On April 5, GSA's public building service said the work would cost $246,0 and it still would not ring the building up to Archives standards.

One GSA official said yesterday that archivist Rhoads was "a very stuck in themiddle. He certainly didn't want to use the Lansburgh building but it was a matter of money. The documents had to be stored someplace."

The official announcement of Rhoads' retirement said it comes at a time that allows him to take advantage of early retirement provisions extended to GSA and other agencies by the Office of Personnel Management. He will be on leave from now until official retirement in Aug. 31, and available to assist Freeman on any ongoing operations problem, the statement said.

Rhoads was named the fifth archivist of the U.S. on May 2, 1968 having worked his way up through the ranks after joining the Archivist until a search for a successor to Rhoads can be made, Freeman said.