St. Louis (KSDK) - Many women will go to great lengths for sleek, shiny hair. And from products to styling tools, there is a lot of help out there. But we have a warning about one product in particular. Some say it's downright dangerous.

From blow outs to salon treatments, you have many options for taming your mane. But it does start on the inside.

"I think the most important thing to remember about smooth and sleek hair is that it's healthy hair," says Derek Fatheree, stylist and owner of Pure Natur Aveda Salon Spa in Fairview Heights, Illinois.

Most of the time, we are on our own, in our own bathroom with a plethora of products.

That's where the Sleek and Shine line from Garnier Fructis comes in. We found the anti-frizz serum made by beauty giant L'Oreal at a local drug store for about $6. It promises "the most intense smoothing yet."

But more than one lawsuit links the serum to serious fires. A teenager in Arkansas says she suffered life-changing burns when she put the serum on her hair and used a comb heated on the stove to smooth it.

And four women got approval for a class action lawsuit against L'Oreal, claiming the two main ingredients are indeed flammable when used with everyday styling tools. Those are silicone based cyclopentasiloxane and dimethiconol and they are used in a lot of cosmetics.

Just how dangerous can they be? Fatheree sees firsthand the damage we do.

"They're shampooing and conditioning daily. They may not be using the best product in the world and then they're blow drying their hair with heat. They're styling it with a curling iron or with a flat iron, often times in excess of 400 degrees, and some people multiple times a day," he said.

We put the serum to the test on real human hair, and had a fire extinguisher nearby, just in case. We found several sources that put the flash points of the two silicone based ingredients at anywhere from 122 to 171 degrees Fahrenheit. That's the lowest temperature at which a flame can ignite vapors from a combustible substance. Flat irons can get as hot as 450 degrees, or hotter.

"All products have a high concentration of water in them and most of it is not smoke. It's just steam," says Fatheree.

But when we took the flat iron to the hair with Sleek and Shine on it, that wasn't just steam. Fatheree says, "It definitely smells like burnt hair. You can smell it."

Human hair is flammable. When we took a lighter to a section of hair with no product on it at all, it burned. And from birthday candles to lighters, hair is sometimes exposed to fire danger.

When we took a lighter to a section with Sleek and Shine on it, it caught fire quickly and burned quickly. The bottle we bought has no warnings about flammability at all.

Fatheree offers these recommendations when it comes to buying cosmetics. He says to look at the ingredients on the back of the product. If one of the main ingredients (listed first) is a silicone based product, avoid it. Products high in silicone coat the hair with continued use and create a "waxy" layer on the surface of the hair strand. Over time, the waxy layer starves the hair of necessary moisture and protein, making it dry, brittle and very unmanageable.

We asked L'Oreal for an on on-camera interview about Sleek and Shine. They sent us this statement:
"This matter is currently in litigation and, as such, we cannot comment. However, we strenuously contest these allegations and have absolute confidence in our product, which millions of consumers have used safely for many years."

If you are interested in joining the class action lawsuit, contact attorney Grace Tersigni with KamberLaw LLC in New York City, NY, by e-mail at