The methods used to conduct tests on flooring samples are at the center of a controversy involving Lumber Liquidators and the levels of formaldehyde in its laminate flooring. Recent news reports allege that the company’s Chinese-made laminate products greatly exceed California’s stringent clean air regulations.

As CBS’s "60 Minutes" reported Sunday night, three independent tests of Lumber Liquidators’ flooring found levels of the cancer-causing chemical to be off the charts: The average level in Lumber Liquidators laminate products was over six to seven times above the state standard for formaldehyde, Anderson Cooper reported. “We found some that were close to 20 times above the level that's allowed to be sold.”

The media coverage has set off worries about indoor air quality and the health of their homes among consumers--some homeowners in California are ripping out their Lumber Liquidators flooring.

The flooring retailer insists that its flooring is safe and has questioned the approach the network took to test the formaldehyde levels: “We believe that 60 Minutes used an improper test method in its reporting that is not included in CARB’s regulations and does not measure a product according to how it is actually used by consumers,” the company responded in a statement.

In response, CBS and the labs that performed the tests have stood by the testing methods, which measured formaldehyde levels inside the core of the samples, a protocol set by California’s Air Resources Board (CARB). “To say we used the wrong tests is not accurate,” says Kip Howlett, president of the Hardwood Plywood & Veneer Association (HPVA), whose independent lab conducted some of the testing. “CARB regulations are very specific about laminated products like these--that the surface needs to be taken off so you can test the underlying core material.”

Having several sets of results with the same findings helps back up the efficacy of the tests, he says. “The labs split the samples and were very careful to make sure they got reproduceable results.”

Reston, Va.-based HPVA Laboratories is a third-party certification agency that offers testing on a range of flooring issues including VOCs, fire resistance, and structural issues. The lab operates independently from HPVA, an association representing hardwood plywood, hardwood veneer, and engineered hardwood flooring manufacturers in North America. The group’s members have long been concerned about unfair trade practices that stem from cheaper imported goods, says Howlett.

Complying with CARB standards costs domestic flooring manufacturers up to $50,000 for initial certification, up to $24,000 for yearly costs, and slows the production process by about 25%, he adds.

“Domestic manufacturers have paid a lot of money to be in compliance, and basically the California rules have become the de facto national standards, because nobody carries one inventory for California and one for the rest of the country,” he explains.

He says Lumber Liquidators’ use of cheaper Chinese wood gives the company an unfair—and possibly illegal--advantage. “It’s not by accident that China has 60% of market in flooring and hardwood plywood,” he says. “It’s gained market share in the U.S. based strictly on price advantage.”