For six months, teams of specialists had been scouring a new, three-story office building in Connecticut for the source of mysterious vapors that had plagued its occupants since the building opened. Employees complained about a "wet kennel" odor and suffered from nausea, as well as eye, ear, nose, and throat irritations. Frustrated, the insurance company that leased the building was considering abandoning it.

But then a team from TRC Environmental Consultants Inc. in East Hartford brought in some newly acquired Canadian technology, the TAGA (Trace Atmospheric C as Analyzer) 3000. In one day, the device pinpointed the problems: dimethyl acetamide solvent used in plastic wall panels, butylacrylate solvent contained in carpeting glue, and a ventilation system with the exhaust too close to the intake. A month later, office workers were breathing easy again. The one-day service, which cost $5,000, had saved a $5 million building.

TAGA may be the best thing to happen to office air since ventilation. At the moment, there are only a handful of the devices in the United States: TRC operates two; Roy F. Weston Corp., a West Chester, Pa., consulting firm, leases two; the state of New York has its own. Nevertheless, TAC A proraises to be a minor godsend for companies with indoor air quality, industrial hygiene, or hazardous waste problems.

In the past, such companies would have to hire someone to collect gas samples on site. The samples would then be concentrated and sent to a laboratory for analysis, using traditional gas chromatography or mass spectrometry techniques, or a combination of both. The process relied on a certain amount of guesswork: You had to pick your samples well. Moreover, it was time-consuming (up to two weeks in the lab) and expensive ($400 to $1,000 per sample).

The TAGA 3000, by contrast, is mobile and operates on the premises. Mounted on a 26-foot GMC Motorcoach, providing continuous analyses as it goes. As a result, it can isolate sources more quickly -- and identify chemical components more completely -- than any other technology around, leading to dramatic savings in search time and expense.

"We've done as many as 800 analyses in one day," cutting per-sample costs to $6.25, says TRC vice-president Richard Duffee, "and we could have done more."

Equally important, TAGA has incredible sensitivity, measuring substances in parts-per-trillion, as opposed to the usual parts-per-billion. It can thus zero in on compounds that would have escaped detection previously. "We're seeing things now that we just didn't see before," says Duffee.

Both the TAGA 3000 and a more elaborate model, the TAGA 6000, are space-program spinoffs. They came out of a project with the University of Toronto to design a device for analyzing a rocket engine's exhaust during firing. The university researchers later set up a company, Sciex Inc. (acquired in 1981 by MDS Health Systems Ltd.), to make TAGAs.

TRC discovered TAGA about a year ago and has already used it on some 100 contracts. "It's now involved in about 20% of our work," says president Vincent A. Rocco. The company, which had revenues of $8 million last year, recently set up a joint venture with Sciex, called TRC Advanced Analytics Inc., to act as the exclusive supervisor of TAGA services in the United States and Canada. Meanwhile, Sciex will continue to sell and ease the units to companies for their own use.