But the effort is being hampered by differing views on how hazardous the debris materials are and whether specialist firms must be contracted.

At the heart of the debate is asbestos - a fiber used as a fire retardant in parts of the World Trade Center - which can cause lung scarring (asbestosis) and cancer if inhaled over a sustained period.

While the authorities say the levels of asbestos in the air around the World Trade Center site is not dangerous, companies which handle hazardous materials say the dust that has settled in and on surrounding buildings still needs to be handled with great care.

They allege that workers who until a few weeks ago were janitors are unqualified, unprotected, and uninsured to handle this kind of cleanup.

"What looks clean is not clean. What remains are the small pieces that are the real risk," said Michael O'Reilly, chief executive of Trade-Winds Environmental Restoration, Inc., the division of Windswept Environmental Systems Inc. that has sent over 400 trained and certified hazardous material specialists to work for "Fortune 100 firms" at more than a dozen sites. Trade-Winds workers say they have seen janitors handling potentially toxic dust, O'Reilly said.

"We'll be cleaning up after them for maybe six months," O'Reilly said.

JANITORS, UNIONS

The criticism represents a dilemma for ABM Industries Inc., the nation's No. 1 public building maintenance firm. ABM saw nearly 1,200 workers, most of them janitors, displaced when the company's $65 million World Trade Center contract - which was its largest - disappeared when the attacks destroyed the complex and claimed nearly 5,600 lives.

ABM President Henrik Slipsager said the company worked out a deal with the Service Employees International Union to offer the displaced workers temporary jobs until new permanent positions can be found.

One Source, the No. 2 public janitorial services company and a unit of the Carlisle Group Plc., has had 400 janitors out of work at eight buildings in lower Manhattan since the attacks.

Allen Marquesano, the company's New England Regional Manager, says One Source has been sending some of its displaced janitors into New York's financial district - previously home to up to 30,000 people and thousands of businesses.

One Source janitors are equipped with Occupational Safety and Health Administration-approved respirators and 30 brand new $500 high-efficiency particle vacuum cleaners.

"We don't need the money - we (provide for) our clients the service where and when it's safe," Marquesano said, adding that One Source workers have seen companies that jumped the gun to get work doing decontamination for which they had questionable training.

"I've seen guys who are normally doing computer dusting trying to do decontamination," Marquesano said. "Their guys are even less qualified than ours."

BUILDING OWNERS

Caught in the middle of the finger pointing between hazardous materials workers and janitors are the building owners who are trying to get their buildings cleaned up enough to reopen.

Brookfield Properties hired, among others, Hillman Environmental, to handle the "heavy dirt" that spilled through the 600 broken windows at its One Liberty Plaza building, just across the street from the World Trade Center, said the company's president Rick Clark. It then sent his company's regular janitorial services company, Triangle, in to do the "fine stuff," he said.

"They'll have to do that several times over," said Clark referring to Triangle's detail work.