To listen to Jack Janick tell it, life in the dry cleaning business these last few years has been one difficulty after another.

"It's been hell," said the 50-year-old Princeton, N.J. dry cleaner with a sigh. "First it was the wash-and-wears that almost put us out of business. Then it was double knits. And now it's OSHA."

As almost any businessman, big or small, can attest these days. OSHA is not the latest wrinkle-resistant miracle fiber. OSHA is the Occupational Safety and Health Administration, the Labor Department's chief regulatory agency and the nemesis of the business world since it was formed in 1970.

Now the federal agency has marshalled its forces for its most ambitious regulatory effort to date - an attempt to streamline and toughen the laws covering some 2,000 suspected cancer-causing substance federal experts say are to be found in the U.S. workplace.

The project is the focus of a massive set of public hearings under way here and expected to last deep into the summer. The hearings, the largest and most comprehensive ever held by OSHA, and both industry and federal regulators agree they are the first broad-scale effort by the government to get public opinion on regulatory efforts involving suspected carcinogens.

"The significance of this goes far beyond OSHA," said Ronald Lane, executive director of the American Industrial Health Council, a trade group formed last year specifically to do battle with the OSHA proposals.

In the past, regulatory agencies have held hearings on specific suspected workplace carcinogens such as vinyl chloride or arsenic. But no such hearings were held, for example, before the Environmental Protection Agency put its cancer policy into effect in 1976.

"They just announced that they were going to do it and waited for a reaction," Lang said.

The opportunity this time has not gone unnoticed by the business community. Lang's group, which is composed of about 90 companies and 60 trade associations, has a $1.3 million war chest. AIHC staffers monitor the daily hearings and churn out a flood of transcripts and instant analyses of testimony by business-oriented experts. In addition, for group maintains a "hotline" for anyone who wants up-to-date information on the progress of the hearings.

"The hotline was set up for the press," said Lang. "But we're getting calls from businesses who want to know what's going on."

The hearings have become something of a watershed for industry, which has been trading complaints and accusations with federal regulators for years. The list of those lining up to speak takes up 20 typewritten pages and ranges from big-name firms like B.F. Goodrich, Dow, du Pont and Shell to outfits like the National Cotton Batting Institute, the Adhesive and Sealant Council and Janick's group, the Neighborhood Cleaners Association.

The stakes for everyone on both sides could be enormous, federal and business officials agree. "We know these proposals are going to be the basis for similar plans by other federal regulatory agencies," Lang said.

Under the proposal, which takes up nearly 100 tightly written pages, suspected carcinogens will be generally grouped and placed in four categories. The most suspect - those which have been shown to cause human cancers or cancers in two species of mammalian animals or tumors in two sets of the same species - will receive immediate attention in the form of tough emergency exposure standards.

Last winter, after the proposed regulations were first made public, Lang's group commissioned the consultants Booz, Allen and Hamilton to estimate the cost. The consultants came up with a "worst case" figure of $88 billion in new equipment for U.S. businesses.

Some federal regulators, however, claim that the cost figure is a scare tactic which has been tried before and proved false.

Grover Wrenn, director of OSHA's health standards program, noted in an interview that, during hearings severl years ago on the suspected carcinogen polyvinyl chloride, industry experts produced estimates that sharply lowered exposure standards for workers could cost thousands of jobs and millions of dollars.

"I'm not saying we exactly helped them along with our PVC standard, but their business volume today is higher and the losses just didn't materialize," Wrenn said.

OSHA has a good deal riding on the hearings also. The agency has planned to double its health standards staff - now around 50 - if the regulations go through. Moreover, leading the way in the area could mean a badly needed boost in morale for OSHA, which has been perhaps the most heavily criticized of all the federal regulators.

Business has complained that OSHA's enforcement of work safety rules in the past has been done in erratic drips and drabs. The General Accounting Office sharply criticized OSHA recently for failing to spot correct those it did find.

"We are hoping," said Wrenn, "That these new regulations will be in place inside of 18 months and will take us from the caboose of the federal regulating train and put us out in front."

So far the hearings, which started in May, have generated little notice outside of the business community. Only a handful of spectators show up for the daily sessions at the Labor Department's auditorium here, and testimony generally drones through technical explanations of why the new regulations are good or bad.

Within the next week, however, OSHA officials and industry observers expect a sharp spurt in activity, when Wrenn's office posts a list of 261 "Category One" substances which it deems most dangerous of those found in the workplace.

Industry has already dubbed it a "hit list" and warned of possible heavy economic losses when the regulatory agency's prioritics are made public.

"We expect to have people with items on that list pounding on their congressman's door," said Lang.

"There will be a lot of oxes gored," concedes Wrenn. His agency, he said, is bracing for a torrent of complaints.

"Change," he said, "is rarely achieved without some cost."

In all likelihood dry cleaner Janick will be one of those who will have to pay part of that cost. His three shops in southern New Jersey use a solvent called perchloroethylene, a chemical compound which the National Cancer Institute says causes cancer in laboratory animals.

The Dry Cleaners News has been running ads in its recent issues warning businessmen that they might have to replace some of their equipment to meet the proposed perchloroethylene standards.

Janick says that could mean an out-of-pocket expense of around $50.000 to equip his three shops with new cleaners, reclaimers and "sniffers," a machine that looks like an octopus and sucks up stray fumes from the work area.

The $50,000 price tag will hurt. Janick said, especially after years of lean business brought on by the advent of synthetics that do not require dry cleaning.

"There is no insurance you can get for a federal regulation." he said. "Just when people are turning back to natural fibers and business picks up they come along with this, and look what happens. This is going to set me back to ground zero."

Recently Janick met in his Princeton shop with Sid Prestup, the dry cleaning machinery salesman for his part of New Jersey. They talked in Janick's words, "big bucks" to meet the proposed regulation requirements.

"We've advertised that this is coming," said Prestup, "but our education is going slowly. A lot of our customers don't like it one bit."

In the end, however, Prestup said his business clients are likely not only to weather the new regulations but actually save money once the machinery is in place.

"It could be a little rough when they change over," he said. "But once they do, the cost of their operation is going to come way down. My guess is they'll survive all this just fine."