DENVER -- At first, you wouldn't notice a difference inside the production warehouse at Denver Mattress Company.

But General Manager Bob Rensink pointed out an added spool of fiber on the assembly line.

The fluffy, white matting placed just under the top fabric layer of every mattress is actually a rayon-based fiber which meets the new federal requirement for a flame barrier.

The U.S. Consumer Product Safety Commission standard, effective July 1, 2007, requires all mattresses and mattress foundation sets sold in the United States to withstand an open flame blowtorch test for 70 seconds.

Denver Mattress Company burned hundreds of beds and researched dozens of options, including chemically treated barriers, for 2 years before deciding on the rayon fiber.

"This is a rayon fiber blend that chars. It's inherent in the fiber. It doesn't need a chemical solution sprayed onto the fabric," Rensink said.

Rensink says it costs more than chemical treatments, but the company felt it was worth it.

How manufacturers meet the CPSC standards is up to them.

"There's different things they can use. A very popluar one is cotton bedding with boric acid, roach killer, mixed in," said Mark Strobel, president of Strobel Technologies, a specialty mattress company in Indiana.

Strobel has launched a personnal crusade against the new law, compiling experts and evidence to support his claims that the flame tests are extreme and the chemicals approved for use have not been properly tested.

"With 300 million people in the United States unknowingly taking the risk of sleeping in toxic chemicals, they (CPSC) avoid the one in one million risk of dying in a mattress fire," said Strobel.

He maintains there is no nontoxic system available to make mattresses flame retardant to the extent that the new CPSC standard requires.

In addition to boric acid, known carcinogens like antimony and formaldehyde are also approved for use on flame barriers.

"I'm concerned with the long term health effects of these people who are gonna absorb these poisons every night and what it will do to us over the long term," said Stobel.

"I think people are very concerned," said Rensink.

Many manufacturers are predicting a backlash once consumers start to investigat what's really lying under their sheets with them.

We requested a detailed list of approved fire barrier manufacturing products from the CPSC a month ago and are still waiting to receive it.

For more information visit >www.PeopleforCleanBeds.org or The Consumer Products Safety Commission.