We do some crazy stuff for beauty. Injecting Botchulism, slathering bird poop on our faces (this is not a joke) and letting fish eat dead skin on our feet (again, totally serious). But that stuff probably wont kill us. Certain hair-straightening treatments on the other hand … just might.

A warning about Brazilian keratin salon treatments containing formaldehyde has been issued by the Professional Beauty Association.

Granted, while formaldehyde is most commonly used to, well, embalm the dearly departed, it's also in quite a few cosmetics -- but it's most dangerous when it's made into vapor, which is exactly what happens when get your hair straightened (they put on chemicals... then flat iron your hair).

That means dangerous formaldehyde fumes, known to cause cancer.

Eek, I'm out. There are plenty of safe ways to straighten curly hair. Or why not just embrace your curls? These celebrities do.

• Try some beauty treatments that definitely wont kill you

• Think you know what to watch out for in your makeup?

• Save the world and your face with this