Few people think of the dining room table as a contributor to city smog. But, covered with wet varnish in the factory where it was made, it probably was. The oily coating that goes onto furniture to protect wood and please the eye emits compounds, known as hydrocarbons, as it dries. These rise into the sky and, joining with hydrocarbons from such sources as car tailpipes and chemical plant stacks, help create the smog that cloaks so many American cities.

At Battelle Memorial Institute in Columbus, Ohio, researchers are trying to change all that. They have developed processes by which varnish is cured in a matter of seconds by intense ultra-violet light, rather than over long periods in open air or fume-generating ovens. Most of the pollutants get locked into the finish and don't escape into the atmosphere at all.

While air polluters are bracing nervously for the inevitable toughening of the Clean Air Act, a new boom is at hand for the thriving environmental equipment and services industry. For them, it is a time of celebration because every dollar spent to comply with the landmark legislation will mean new dollars in the tills of companies that make the myriad cleanup technologies.

"Most of them are drooling," joked James Easterling, senior economist at Management Information Services, which does environmental and other consulting. The U.S. air pollution control industry will have sales of about $48 billion this year, his firm estimates, and may enjoy compounded growth of 15 percent a year for the next few years.

Air & Water Technologies Corp. of Branchburg, N.J., is already racing for some of the new business, adding employees and wooing the business of a half-dozen utilities that will have to cut sulfur dioxide emissions. A leading producer of "scrubbers," contraptions the size of a house that clean up coal smoke emitted from utility plants, Air & Water hopes to score big since 107 major power plants across the country could be in the market for at least one of the $100 million devices.

For the past several years, no one has been buying scrubbers, because they either already had them or didn't want to invest in a costly new technology when it was unclear what standards the Clean Air Act would require. Said Don Deieso, president of Air & Water Technologies's air pollution subsidiary, "With the Clean Air Act, the market will move to about $8 billion to $10 billion" over the next decade.

Also on the long and diverse list of pollution controllers that are soon to be more popular: leakproof valves, wind-powered generators, better tailpipe devices for cars, pollution-monitoring gear, cleaner-burning gasoline, vapor-absorbing dry-cleaning equipment, computer software that predicts how far and fast smoke from a given stack will disperse and, in immeasurable quantities, the expertise of lawyers and consultants on how to read the law's fine print and comply with it.

"We're talking in the range of hundreds of thousands of jobs produced," said Robert Rose, a pollution control consultant. These jobs, many of them skilled and high-paying, will help offset the job loss created by companies that decide to close plants rather than bring them into compliance with tougher pollution standards.

As currently written, the law could affect hundreds of everyday products. Take house paints, for instance. They all contain various amounts of environmentally damaging hydrocarbons. In past years, responding to state laws, paint companies have improved their lineups of water-based paints, which generally have five or 10 times less hydrocarbon content than oil-based ones, and developed oil-based ones that give off fewer fumes.

Pittsburgh-based PPG Industries Inc.'s coatings and resins group will expand its research and development with the expectation that the federal act will further spur the desire for low-hydrocarbon paints. "Most of us in the research end have anticipated this act for some time ... " said Neil Frick, vice president of R&D at the group. "We've got to be ready to supply the industry when the new regulations come down."

Elsewhere, technicians are working on ways to filter the air of large spray-painting rooms in auto factories, which becomes heavy with hydrocarbons. Another group of experts is remodeling valves so that they don't leak as much of whatever is passing through them. The design of scrubbers is being rethought by still another group of scientists.

Dravo Lime Co. of Pittsburgh, for example, now has about 30 people working full time on scrubbing technology that will make the bulky devices cheaper and smaller (finding space for them on the grounds of old plants is a serious problem). Without the Clean Air Act's incentive, said Donald H. Stowe Jr., vice president of sales and technology, staffing would have been at about half that number. The goal is to make scrubbers stand up well against other technologies when polluters make tough decisions on how to cut emissions. A welcome side-effect for Dravo: The more scrubbers in use, the more demand for its flagship product, lime, which is consumed in large quantities in the scrubbing process.

The act will also bring with it broad new requirements for information collection and reporting. That means more need for computers and customized software to handle the task, which at a single company can involve the sorting and manipulation of millions of bits of data. It also means the need for electronic sensors to produce the readings. Air & Water Technologies offers units that go for $300,000 to $400,000 each. With units to be needed for close to 350 boilers, officials believe the outlook is good.

Companies contemplating constructing new plants will have to conduct stricter studies on their environmental impact. These are often done in simulation through complex computer software: If a smokestack is 100 feet high, if sulfur dioxide spews out at 10,000 pounds per hour, if the average temperature is 50 degrees, if there is a 500-foot-high ridge a quarter mile to the east, how much of it will reach a town five miles upwind? Such calculations take months by hand but a computer can rip through them in seconds or minutes.

More and more, polluters are coming to believe that the smarter way to comply in the long run is to avoid creating the pollutant at all. Witness the Battelle effort to change the way furniture is made. Or the large sums being spent to make light bulbs burn more efficiently, so that less power is needed and less pollution created. Or the push to clean sulfur out of coal before it is burned, or to make ordinary fuel burn more cleanly.

In a similar vein, the bill would create incentives for utilities to turn their power turbines using "renewable," non-polluting kinds of energy such as wind, solar and geothermal. Companies trying to develop those forms of energy suffered a blow in the mid-1980s with the end of federal tax credits, but they now look to happier days as the bill nudges up the cost of using fossil fuels. "It sends a positive message about using technologies that don't pollute," said Robert Boyd, director of regulatory affairs for U.S. Windpower Inc., a California company that makes and operates wind turbines.

The Clean Air Act will create requirements that many polluting companies won't know how to deal with on their own. Presto -- new demand will materialize for consultants schooled in the esoterica of such things as NOx, a smog-producing nitrogen oxide, clean coal and the voluminous regulations that the bill will generate. "Just about everybody out there who's looking for work I'm sure should be able to find it," said James Coyne, a McLean consultant who specializes in environmental information systems.

Environmental equipment and expertise is gaining importance in trade as countries around the world turn to address problems of air quality. Western Europe and Japan have increased their own demand for the gear through stiff laws. The growth economies of East Asia are starting to worry about the environmental cost of prosperity, and Eastern Europe has pledged to clean up its smokestack squalor. Just last week, General Motors Corp. signed a $1 billion agreement to sell the Soviets air pollution equipment for cars.

U.S. companies lead the world in some pollution control technologies, but they face stiff competition in others -- about half of the wind turbines sold in this country, for instance, are made by Danish firms. In the scrubber market, some experts foresee significant numbers of foreign-built units being sold here, due to insufficient capacity among U.S. suppliers and high quality abroad, particularly among West German makers. In general, the countries for the United States to beat are Germany and Japan, which have lean, competitive industries.

Some analysts, Environmental Protection Agency officials among them, believe the Clean Air Act will in the long run help U.S. trade accounts by whipping suppliers into shape so that they can serve the home market and do well abroad. Said consultant Rose: "This is a real opportunity ... to recover that competitive edge and assure markets over the next 20 years."