Four experts – two toxicologists and two lawyers – gave local builders and contractors a lesson in “Foreign Drywall 101” Wednesday.

More than 200 construction industry members attended the seminar put together by the Cape Coral Construction Industry and the Building Industry Association, which represents Lee, Hendry and Glades counties, about drywall imported from China during the recent construction boom that has been the subject of about 100 complaints across Florida.

The drywall is made of naturally mined gypsum and has been most heavily linked to the Knauf Plasterboard Tianjin, a German-based company that manufactures the drywall in China.

The suspect drywall is believed to cause copper air conditioning coils to turn black, in addition to tarnishing other metals such as brass. Some Florida residents have said the drywall smells like sulfur and has caused headaches and respiratory problems.

Florida Department of Health toxicologist Dr. David Krauss said his agency is conducting initial tests on 12 homes containing the drywall, and expects to have results in two weeks.

“It was really a survey to determine if there’s an issue, to help identify some trends,” Krauss told reporters after the seminar.

Krauss said more comprehensive tests on a wider range of cases will be conducted depending on the initial test results, but no serious health hazards have been discovered thus far.

“We have not seen anything to raise alarms as far as exposure to corrosive gases themselves,” Krauss said. “Available data has not identified levels of corrosive gases that exceed those recognizable as posing a risk to health.”

Florida appears to be ground zero for complaints about the foreign drywall, but the scope of the problem is yet to be determined.

“It’s not readily ascertainable where and when it went,” said Dr. Robert DeMott, a toxicologist with Environ, a private environmental consulting firm.

Because a jet black air conditioning coil that causes the unit to seize up is one of the clearest indicators of the suspect drywall, Florida’s tropical climate most likely led to more cases being discovered, while other states like South Carolina and Alabama could be just beginning to discover the problem.

“I think it was sort of easier to pick up here. Until you know a home has had three air conditioning coils replaced you don’t know there’s a problem,” DeMott said.

Some builders and contractors in the audience were concerned about their possible liability over the issue.

Larry Burnes, vice president of Sam Drywall, said he is worried all drywall contractors would get tarred with the same brush.

“I don’t feel all drywall contractors are at fault,” Burnes said, adding that his company did not use the suspect drywall.

Attorney Mark Boyle said that due to a clause in many builders’ insurance contracts called a “pollution exclusion,” which became prevalent after 2003, fault may not matter when determining liability.

“No contractor knew or had any reason to know there was anything wrong with (the suspect drywall). Sometimes it’s not a matter of fault, it’s a matter of you have a contract with somebody,” Boyle said.

For homeowners and builders, trying to extract money from Knauf, the manufacturer, could also be problematic.

Attorney Geoffrey Gentile said he wrote to Knauf asking about its insurance policies.

Its reply was simply, “We have no insurance,” according to Gentile.

While the suspect drywall is believed to have been imported to the area beginning in 2004, as the local housing boom was picking up steam, the controversy surrounding the drywall has hit an industry that has gone bust.

“It certainly didn’t happen at a good time. Builders are struggling now and this doesn’t help matters,” said Carl Schmidt, vice president of construction for the Sterling Collection, a Cape Coral-based home builder.