The Supreme Court agreed yesterday to review a ruling that the government views as a serious threat to "effective implementation of fedcral legislation designed to protect the health and safety of the nation's work force."

The ruling, made by a panel of three federal judges in Idaho last Dec. 30, upheld the refusal of an employer to admit to his work place a government inspector who lacked a search warrant.

Inspection without a warrant violates the constitutional protection against unreasonable searches, the panel said.

Disagreeing, the Justice Department said that the ruling is inconsistent with previous Supreme Court decisions on "closely similar" constitutional issues.

The case began in Pocatelio, Idaho, on Sept. 11, 1975, when Daniel T. Sanger, an inspector for the Labor Department's Occupational Safety and Health Administration went to Barlow's, Inc., an electrical, plumbing, heating and air conditioning, business, to make a routine inspection.

Sanger presented his credentials and explained his mission to Ferrol G. (B111) Barlow, president of the firm, who turned him away because he did not have a warrant.

The 1970 Occupational and Safety Act empowers the agency's 1,300 inspectors to enter, inspect and investigate any of the nearly 6 million work places "without delay and at reasonable time . . ."

Sanger got a judge's order that he be admitted, but Barlow turned him away a second time on Jan. 5, 1976.This led to the ruling of the three-judge panel.

In a brief filed in the Supreme Court, the Solicitor General contended that the ability to make unannounced plant visits is vital to the identification and correction of work, hazards.

The court took other actions: Industrial Water Pollution

In an action that may generate a rescue operation on Capitol Hill, the court led stand a ruling that the Environmental Protection Agency cannot extend the July 1, 1977, deadline in the Water Pollution Control Act for compliance by major industrial polluters with effluent limitations.

The ruling was issued last Nov. 1 by the Third U.S. Circuit Court of Appeals in a case involving the Bethlehem Steel Corp. and its iron and steel manufacturing facilities in Bethlehem, Pa. But the appellate court said that in the entire iron and steel industry, "the sequence of administration actions contemplated by Congress has never taken hold . . ."

The company expects to spend $40 million to comply with the law's requirement for application "of the best practicable control technology currently available" to conform with emission limits at the Bethehem site.

Saying that the company acted in good faith and can't meet the July 1 deadline through no fault of its own, the EPA gave Bethlehem a letter saying it would not enforce civil or criminal penalties for noncompliance.

The effect of the letter was to grant Bethlehem a delay; it says it needs two years. But the July 1, 1977, deadline "was intended by Congress to be a rigid guidepost," the appeals court held. Sovereign "Persons"

The Clayton Antitrust Act empowers any "person" injured by an antitrust violation to sue for treble damages. But is a sovereign foreign government a "person"?

The question arises because the Governments of India, Iran, the Phillippines and South Vietnam are seeking damages from six American companies - Pfizer, American Cyanamid, Bristol-Myers, Squibb, Olin and Upjohn - because they allegedly had conspired in the 1960s to restrain and monopolize trade in antibiotics in the tetracycline family.

The companies, which have paid out vast sums to numerous other plaintiffs, argue that a foreign government is not a "person," and that permitting one to sue will have grave effects on the country's foreign economic affairs.

But the Justice Department contends that Congress did not intend to bar antitrust actions by a foreign government, and the State Department says it expects no "foreign policy problems" if any is permitted to sue.

Yesterday the court agreed to review a lower-court ruling supporting the Justice Department position.