The Occupational Safety and Health Administration, created to protect the nation's 100 million workers, celebrated its 12th anniversary recently in much the same way it has operated since President Nixon signed it into life: under fire.

Given contradictory marching orders by successive administrations--first zig, then zag, toughen up, ease off--OSHA keeps searching for identity and direction. In its first years under presidents Nixon and Ford, it became a symbol of federal regulatory ineptitude, a clerkish agency that fussed about the strength of ladders and shape of toilet seats instead of killer chemicals in the work place.

Under President Carter, it became a stern and righteous cop, scourge of businessmen, much more formidable. Now, changing to President Reagan's friendly persuader, it has stirred up another cloud of criticism.

Under Reagan's audacious young OSHA chief, Thorne G. Auchter, the agency has throttled down or off on many of its regulatory controls, shrinking the scope of work-place inspections and putting a hold on the assembly line of health and safety standards the agency is supposed to produce.

Penalties levied against employers have fallen from $25.5 million in 1980 to $5.5 million in 1982. After producing 24 work-place health standards in the decade before Reagan, nine of them under Carter, OSHA, since 1980, has produced what one congressional critic calls "goose eggs."

Now, in the wake of the scandal that rocked the Environmental Protection Agency, there are signs that OSHA may be adjusting its direction again.

This is just the latest plot twist in a long, unhappy tale. A fiefdom of the Labor Department with 2,260 employes and a budget of about $210 million for 1984, OSHA is dwarfed by its elephantine mission. The OSHA act was part of a great spurt of optimistic legislation in the early 1970s aimed at cleaning up chemicals. The agency's history is a paradigm of how hard these often vaguely expressed good intentions have been to carry out.

It is also a classic example of what deregulation has meant in the Reagan administration.

OSHA never has lived up to the expectations of workers, according to George Taylor, the recently retired former AFL-CIO official who helped draft the legislation that created the agency. "When you get down to the hard realities . . . overall it's been a period of 13 years of frustration."

The regulatory dilemma is particularly acute at agencies such as OSHA, where regulators must rely on a fledgling, uncertain science. It is compounded by ambivalent attitudes in a society where the comforts of life go hand in hand with the generation of some amount of poison and some risk of accident.

The one constant has been the blazing political cross fire. In the superheated atmosphere surrounding the EPA scandals, Democrats such as Rep. David R. Obey (Wis.) and labor leaders such as Taylor stepped up their chorus of accusations that under Reagan the agency had played footsie with industry at workers' expense.

Even a Republican health specialist named Mort Corn, OSHA director under Ford, charged that many top OSHA officials are opposed to laws they are to enforce. "I suspect if you take a good look at OSHA's records, you'd find the same thing" as at the EPA, he added.

Congressional and media bloodhounds are scrutinizing OSHA records. But they have done little more than prove the Reagan administration has been trying, with only mixed success, to keep its campaign promises to lift federal regulations off business' back and end the "arbitrary and high-handed tactics used by OSHA bureaucrats."

What Auchter's critics consider damning revelations often are administration bragging points. A Labor Department review paper earlier this year listed among OSHA's accomplishments "elimination of 200 unenforceable standards" and establishment of labeling requirements on toxic materials "with industry cooperation," affording "effective protection to workers at only 20 percent of the cost" under Carter.

The combative and confident Auchter denied in an interview that his policies have been unethical or harmful to workers and suggested that his accusers either are ignorant of the problems at OSHA or have selfish political motives. He freely admitted consulting with industry but said he also consults with labor and contended his was a more balanced approach than the previous, labor-oriented administration.

Auchter claimed his is "by far the most ambitious regulatory agenda that OSHA has ever had." Targeted for completion by the end of 1984, he said, are 23 safety and 15 health standards, including some revisions of existing standards. Until now, he noted, the agency has promulgated only 16 safety and 24 health standards.

To judge his performance now "is like judging a runner at the 50-yard line when he's right in the thick of things . . . . That's sort of foolish," Auchter said.

Within his first nine months in office, the average number of monthly work-site inspections dropped by more than 18 percent compared with the same period in 1980 under Carter. Inspections in response to worker complaints dropped 33.5 percent. Complaints logged from workers dropped 30 percent. Follow-up inspections decreased 70 percent. Violations labeled serious dropped 37 percent. And penalties levied decreased 65 percent.

In 1980, OSHA had an inspection staff of 1,328. Under Auchter, as part of Reagan's budget-cutting, it has been pared to 981.

Auchter contended he has improved the inspection process by "targeting" only plants with poor safety and health records. Now, instead of trying to spread themselves through all of the nation's 3 million work places, inspectors can concentrate on the most dangerous sites.

But in a recent report, the AFL-CIO called the targeting program a "paper tiger," claiming inspectors spend much of their time doing "record inspections" rather than touring plants. "If the agency is really inspecting more hazardous work places, why isn't OSHA finding more hazards?" asked Peg Seminario, the AFL-CIO health specialist who prepared the report.

Besides putting the brakes on health and safety standards, Auchter also refused to set emergency standards (designed to shortcut the drawn-out non-emergency procedures) for three work-place chemicals--ethylene dibromide, an agricultural fumigant; ethylene oxide, a sterilizing agent used in hospitals, and formaldehyde, a chemcical linked to cancer in laboratory animals. He argued that such standards are too difficult to defend in lawsuits that inevitably follow.

The Consumer Product Safety Commission banned use of formaldehyde after OSHA and the EPA refused to take action. The ban was overturned by a federal appellate court that said the commission lacked evidence.

Following administration policy, Auchter focused on revising a host of standards implemented earlier, including those for noise, toxic substances and cancer-causing agents, always with an eye toward making them less expensive for business.

Several OSHA staff professionals resigned in protest of the new policies. Three doctors who resigned complained that Auchter was not relying on scientific data.

Critics have complained of meetings by Auchter and other OSHA officials with industry executives who have a direct interest in the agency's activities, and documents have been leaked to the media showing industry notations in the margins of OSHA proposals that were later accepted in the agency draft.

On that subject, Auchter said, "I meet with both labor and management all the time," adding that he encourages other top officials to do so. "I have a guy whose title is labor liaison, and all he does is meet with organized labor. I have a labor liaison in each region . . . . Where we can get labor and management to sit down together, we do that," he said.

Concerning procedures and ethics at OSHA generally, he said, "Nothing has been done here without the approval, if you will, of the solicitor of the Department of Labor."

Both business and labor have attacked the agency under Auchter, which may support his claim of evenhandedness. A recent report in Business Week magazine described the Office of Management and Budget as being "up in arms" about Auchter's issuance of "regulations tougher than anyone had expected." His new program to protect workers' hearing, for instance, would cost industry an estimated $280 million, only $80 million less than its Carter counterpart. A similar dispute has been waged over the cotton-dust standard, which the OMB wanted lowered.

Meanwhile, some industry executives have expressed concern that too much delay in setting standards might leave their completion to some future, less sympathetic administration.

Not all labor representatives are critical of Auchter, either. Said Robert Georgine, head of the AFL-CIO's building and construction trades department: "We have developed a good working relationship with Auchter, and we've been able to work out some good programs." But, he added, "Cutbacks are cutbacks."

A millionaire, Auchter worked for 20 years in his family's construction firm in Jacksonville, Fla., before becoming executive vice president of the company in 1975. He has worked as a carpenter apprentice, field engineer and occupational safety and health officer. In 1970, he was appointed to the state's task force on occupational safety and health.

Friends and foes praise Auchter for shrewd political sense and ability to manipulate bureaucratic levers.

The administrator's chair at OSHA has never been a magnet for adulation. For instance:

* In the agency's first year of operation, OSHA bureaucrats reported issuing more than 26,000 citations, proposing nearly $2 million in penalties and conducting 29,255 inspections. Critics say they were being too hasty.

* In 1972, as later revealed by a Senate Watergate investigating committee, OSHA officials delayed or toned down implementation of health and safety standards as a "sales point" to attract business contributions to Nixon's reelection drive.

* In 1974, a Senate labor subcommittee charged that OSHA was "shackled by administrative ineptness." While workers might be exposed to 25,000 different toxic substances, of which 1,000 to 2,000 may require exposure standards to be set and of which 471 are of high priority, said then-Sen. Harrison A. Williams Jr. (D-N.J.), "OSHA has promulgated standards for only three . . . ."

* In 1975, OSHA reported that it had so few inspectors that the average employer would see one "only once in 66 years." It had issued standards for only four toxic substances.

* By 1977, polls showed that the agency had become the most hated in the federal bureaucracy. It nagged businessmen about the shape of toilet seats, used 35 pages of small type to define a proper exit sign and sent bulletins to farmers warning them that cow manure could be slippery.

Not until the end of the Ford administration, under Corn, and throughout the Carter years, under administrator Eula Bingham, did the agency begin to focus on the serious and elusive area of the "ticking time bomb" of unknown chemical hazards.

While she pruned back layers of red tape, Bingham made labor leaders happier and gave businessmen a new headache by formulating nine major new health standards in 3 1/2 years on such deadly substances as lead, benzene and arsenic. Industry fought her every step. In at least one case, the Supreme Court took her opponents' side, striking down the standard for benzene on grounds that OSHA had not proved that the substance is a direct, serious hazard requiring regulation.

"In the later years of the Carter administration," an AFL-CIO official said, "the research documents and leadership of OSHA were just beginning to be respected."

But Auchter said that, by the time he took over, the agency was facing "tons of litigation . . . all over this country, at every level of court you can imagine."

Scientists and government officials disagree about the number of Americans who die each year from conditions in the work place, and most acknowledge that there is no way to know for sure. OSHA's research arm, the National Institute of Occupational Safety and Health, estimates the number at as many as 100,000 deaths per year. Surveys focusing only on "known" deaths cite as few as 100.

Also impossible to measure is OSHA's impact, but specialists say some is discernible. For example:

* There are fewer lung problems in the textile mills, where labor specialists report about 80 to 85 percent compliance.

* Lead levels in blood have been reduced significantly.

* People no longer go into reactor vessels where they would be exposed to vinyl chloride, so there are fewer angiosarcomas, malignant tumors containing many dilated blood vessels.

But, even where the science is relatively clear, the going is slow. Asbestos, for instance, is now documented as a killer. The "wonder substance" once used everywhere for heat insulation was the first toxic material for which OSHA adopted standards, based on European studies.

In 1972, the rules permitted a worker to breathe five fibers per cubic centimeter in an eight-hour period. That was lowered to two fibers in 1976.

At this level, it is estimated that 25 percent of those working with asbestos, inhalation of which can cause a form of lung disease and cancer, will die prematurely as a result. In an internal study Aug. 12, 1981, two NIOSH scientists claimed that as many as 500,000 U.S. workers would develop lung cancer unless the government toughened standards on asbestos.

Until recently, OSHA said a revised standard would not be issued until September, 1985. But, under intense pressure from unions and scientists, it has agreed to propose tougher limits by later this summer and perhaps issue a new rule this fall.

Critics complained that the agency did not make asbestos a top priority until news of the internal report leaked four months ago. Auchter responded that following proper administrative procedures takes time.

In the wake of the EPA furor, employes and others at OSHA reported that the pace and policy thrust of work there appeared to have changed suddenly. In addition to the recent speedup on an asbestos standard, the agency also accelerated action on a toughened benzene standard and retrieved a drastic revision of its controversial cancer policy that had been nearing final action. Now OSHA is making the policy tougher instead of gutting it, as labor critics said had been planned.

"We don't stick our heads in the sand around here. Certainly we were aware of what was going on at EPA," Auchter said. "I don't think it changed our approach to anything . . . . I can't tell you what percentage of what made me make some decisions." Much of the change, he said, was the result of matters in the pipeline coming to fruition.

Noting his agency's troubled history, Auchter said he hopes to leave a legacy of stability and a solid management system that would for the first time hold the agency on course and provide a fair method of judging its impact.

But former AFL-CIO official Taylor suggested it would take more than that. Repeating something he said years ago in a congressional hearing, he said: "Occupational health and safety always has been the illegitimate child at the family reunion . . . . No one gives a damn. If 23 people get swine flu, the whole government is turned upside down, but you can have carnage in the work place and no one cares. If we did, we'd have a program that works."