What's the latest service at the salons? A Brazilian blow out uses leave-in conditioner and a blow dryer to straighten your hair. Allegedly the results last longer and are *ahem* more permanent. This is achieved by using formaldehyde, a known carcinogen. Yes, the same preservative that soaked the frogs you dissected in high school...applied to your head.
The cheaper less toxic solution? Break out your own organic conditioner--any type will do, including the traditional kind that you typically rinse out. Apply a layer, plug in your hair dryer and dry your hair without removing the conditioner. Gently comb while you blow out your hair and you'll end up with soft, straight hair.
For more information about toxicity in beauty products, consult The Environmental Working Group's Skin Deep Cosmetic Safety Database. Always remember there is no federal agency that regulates the cosmetics industry.
