The Reagan administration, in an abrupt reversal of government policy, told the Supreme Court yesterday that it wants to reconsider a major regulation protecting industrial workers from lead poisoning to determine whether the federal health rules are too costly for industry to bear.

With its petition to the court, the Labor Department shifted sides in the five-year lead standard controversy, joining a coalition of industries that opposed the Carter administration's efforts to require an extensive cleanup of smelters, foundries and other industrial installations where lead exposures create health hazards.

Labor Department officials said that in seeking a complete review of the lead standard, the department is complying with President Reagan's Feb. 17 executive order requiring federal regulators to weigh costs and benefits of major rules.

The lead standard, and an equally controversial health regulation intended to control the cotton dust hazard in textile plants, have become the test cases of the administration cost-benefit policy.

During the Carter administration, the Labor Department's Occupational Safety and Health Administration (OSHA) took the position that cost-benefit analysis was not required, siding with the United Steelworkers of America against the industries. OSHA said its assignment from Congress was to require companies to go as far as they feasibly could, economically and technologically, to protect workers from toxic chemicals and other hazards.

The lead standard, issued Nov. 14, 1978, was OSHA's most far-reaching regulation, not only setting up strict lead exposure limits, but also directing companies to protect workers with high lead levels in their blood by moving them to "cleaner" job sites at no loss in pay until their conditions improved. Some 800,000 workers are exposed to lead at varying levels.

Companies were permitted to equip workers temporarily with respirators to prevent inhalation of lead fumes, but OSHA insisted on better ventilation and other engineering changes as a permanent solution in most cases.

This issue -- the use of respirators versus the far more expensive engineering changes -- is at the heart of the debate over costs and benefits. The industries say the greater costs of engineering changes are unreasonable. The Steelworkers union cites studies showing respirators aren't effective protection.

The Carter administration's lead standard was upheld by the Court of Appeals for the District of Columbia last August in most respects, in a 2-to-1 verdict.

Yesterday, the new administration asked the Supreme Court to take the lead case on appeal and, at the same time, strike down the Court of Appeals verdict to permit a full review.

OSHA administrator Thorne Auchter said the exposure limits and health monitoring rules issued by the Carter administration in the 1978 regulation will remain in effect while the review proceeds. "Lead is a serious industry hazard against which workers must be protected," he said in a statement issued by the agency.

"The standard stays in effect. We intend to enforce it," said T. Timothy Ryan Jr., solicitor of Labor.

Companies will not be required to meet the timetables for making engineering changes in their plants, however, since that controversial part of the regulation had previously been frozen temporarily by the Supreme Court.

"I believe that balancing costs and benefits can help produce better, more responsible standards," Auchter said. "Our reviews of the lead and cotton dust standards will enable us to explore the utility of cost-benefit data as an additional decision-making tool to use in setting worker health regulations."

In addition, OSHA said that it wants to reconsider whether the current lead exposure standard is "technologically and economically capable of being achieved" and if so, how soon, and whether the rule requiring "medical removal" of workers with high blood lead levels from job sites is feasible.

OSHA's decision on these economic issues will set administration policy for the regulation of all workplace health hazards, Auchter indicated.