Cynthia is feeling crabby…I heard a rumor that many cosmetic products use crab shells as an ingredient. This sounds a little bit ridiculous to me but if it’s true I wonder why it’s so hush-hush. Is it because the cosmetic companies are worried that the animal-rights activists will find out?
The Beauty Brains respond:
Actually, Cynthia, crab shells are a legitimate ingredient in many cosmetics.
What is chitin?
You’ll never see “crab shells” listed as an ingredient. Instead you’ll see some version of a chemical called “chitin.” Chitin is a polysaccharide which means it’s sort of like cellulose and it comes from the exoskeletons of crustaceans, insects and even arachnids. When you realize this stuff could come from scorpions suddenly crab shells don’t sound so bad.
Chitin was “discovered” in 1811 by Professor Henri Braconnott. He found it, in all places, in the cell walls of mushrooms. I’m guessing that it’s too expensive to get significant amounts of high-quality chitin from mushrooms hence the use of crustacean shells. That’s much more cost effective since these shells are a by product of the animals we use for food (crabs as well as shrimp and lobsters.)
One of earliest applications for chitin was in preparing wound dressings where its moisture retention properties speed the healing of burns. Today it’s found in a variety of products including diapers, feminine napkins, and tampons. (Since these aren’t cosmetics they don’t have to provide an ingredient list.) It’s also an additive in many dietary supplements and, of course, it’s used in cosmetics or else we wouldn’t be writing about it.
What does chitin do in cosmetics?
It has been demonstrated that the addition of certain chitin derivatives significantly improves the skin hydrating properties of facial masks. In addition, chitin is used in hairsprays to increase combability, stiffness and curl retention. It can even help stabilize emulsions by reducing oil and water separation. Look for it on the ingredient list as either chitin or “chitosan.”
While it’s no secret that many products may contain ingredients derived from crustations I don’t think it would be a particularly wise marketing move for products to exclaim “Hey, I’ve got crabs!” Maybe that’s why the animal rights groups haven’t made much of a fuss about this ingredient. Somehow marine-derived ingredients seem to get a pass from the animal rights folks (with shark liver oil being a notable exception.)