Lumber Liquidators' stock plunged Monday after the Centers for Disease Control and Prevention said people exposed to certain types of the company's laminate flooring were three times more likely to get cancer than the agency previously predicted.
The CDC said that in its original report it had used an incorrect value for ceiling height. It said that resulted in health risks calculated using airborne concentration elements about three times lower than they should have been.
It now estimates the risk of cancer at six to 30 cases per 100,000 people. It previously estimated two to nine cases per 100,000 people.
The agency said its recommendations will likely stay the same - that people take steps to reduce exposure to formaldehyde emitted from the Chinese-made flooring.
Formaldehyde was added to the government's list of known carcinogens in 2011. It is a colorless gas with a pungent smell, used among other things to manufacture building materials and household products. It's a common indoor air pollutant. Researchers say the amount of formaldehyde given off by new products ebbs over time.
Lumber Liquidators said in a statement Monday that it has strengthened its "quality assurance procedures," such as testing sample products.
The company stopped selling the Chinese-made laminate floors in May, a few months after CBS news show "60 Minutes" reported those floors contain high levels of formaldehyde. Lumber Liquidators, based in Toano, Va., also began providing customers with free air quality tests.
The CDC said homeowners can reduce the amount of formaldehyde in their homes by letting in fresh air for a few minutes every few days and choosing products with low or no formaldehyde. The health agency said it's not necessary to test homes unless there's a strong chemical smell or someone is having symptoms - burning of the eyes, nose and throat - and only experiencing them in the home.
Earlier this month, it was announced in a separate case that Lumber Liquidators would pay more than $13 million for illegally importing hardwood flooring, after the company pleaded guilty to environmental crimes last year.
Shares of Lumber Liquidators Holdings Inc. slid $2.81, or 19.8 percent, to close at $11.40 on Monday. Its shares have fallen more than 83 percent over the past year.