The Federal Trade Commission (FTC) is warning 78 companies across the U.S. that they may be breaking the law by selling clothing and other textile products that are labeled and advertised as "bamboo," but actually are made of manufactured rayon fiber.

The warning, sent in letters by the agency's staff sent last week, tell the retailers of the FTC's concerns about possible mislabeling of rayon products as "bamboo," so the companies can take corrective steps to avoid Commission action.

"We need to make sure companies use proper labeling and advertising in their efforts to appeal to environmentally conscious consumers," said David C. Vladeck, Director of the agency's Bureau of Consumer Protection. "Rayon is rayon, even if bamboo has been used somewhere along the line in the manufacturing process."

The FTC sued several companies last year for allegedly selling products labeled or advertised as "bamboo" that in reality were made of rayon. Rayon is a man-made fiber created from the cellulose found in plants and trees and processed with harsh chemicals that release hazardous air pollution. Any plant or tree -- including bamboo -- could be used as the cellulose source, but the fiber that is created is rayon.

"While we have seen action by some retailers to correct mislabeled clothing and textile products, our hope is that these warning letters will serve as a wake-up call to all companies, regardless of their size," Vladeck said.

The FTC staff letter outlines the requirements for proper labeling and advertising of textile products derived from bamboo. The letter states, "Rayon, even if manufactured using cellulose from bamboo, must be described using an appropriate term recognized under the FTC's Textile Rules...Failing to properly label and advertise textiles misleads consumers and runs afoul of both the Textile Rules and the FTC Act."

In the letter, the FTC tells the companies they should review the labeling and advertising for the textile products they are selling and remove or correct any misleading bamboo references.

Along with the warning letters, the agency sent each company a synopsis of FTC decisions finding that the failure to use proper fiber names in textile labeling and advertising was deceptive and violated the FTC Act. Under the Act, the FTC can seek civil penalties of up to $16,000 per violation against any company that receives this information but fails to correct its advertising and labeling.

Companies that were sent warning include small and large retailers, with both online and brick-and-mortar stores, and firms selling textile products labeled or advertised as "bamboo" that may be made of rayon. The more commonly known retailers include:, Barney's New York, Bed Bath & Beyond, BJ's Wholesale Club, Bloomingdale's, Costco Wholesale, Garnet Hill, Gold Toe, Hanes, Isotoner, JC Penney, Jockey, Kmart, Kohl's, Land's End, Macy's, Maidenform, Nordstrom,, QVC, REI, Saks Fifth Avenue, Sears, Shop NBC, Spiegel, Sports Authority, Target, The Gap, The Great Indoors, Tommy Bahama, Toys R' Us, Wal-Mart, and

This latest announcement follows four FTC enforcement actions brought against companies selling rayon products that were misleadingly labeled and advertised.

According to the Commission's complaints, filed in August 2009, the companies falsely claimed that their rayon clothing and other textile products were "bamboo fiber," marketing them using names such as "ecoKashmere," "Pure Bamboo," "Bamboo Comfort," and "BambooBaby."

The complaints also challenged a number of other deceptive "green" claims, including that the products retained the bamboo plant's antimicrobial properties, were made using environmentally friendly manufacturing processes, and are biodegradable.