Hi, I'm Craig.

I smell vaguely of chlorine, and this is Mental Floss on YouTube. Today I'm going to answer capselo's big question: "Why does my hair feel dry after swimming in chlorinated water?"
As a practically bald man, I have no idea what you're talking about. But let's get started. 

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So humans can contain something called sebaceous glands, which are found all over the skin, but also on every hair follicle. And some follicles have more than one gland. These glands secrete an oily substance known as sebum, and the purpose of that substance is to make our skin and hair resilient to water. It also keeps our hair moist, and can distribute antioxidants. It's also fun to say sebum. Sebum is mostly triglycerides, but it also contains some wax esters, squalene, and fatty acids. Squalene is also fun to say. Boy, what a day we're having.

And you probably know that chlorine is a chemical element, but there's different types of chlorine that can go into a swimming pool. People use it because it helps keep the pool clean by preventing bacteria and algae from thriving. The most common type is liquid chlorine, which typically contains about 10% chlorine. There's also tablet chlorine, stick chlorine, granular chlorine, powdered chlorine, fried chlorine.. um, buttered chlorine, the list goes on. Fictionally.

You're probably thinking, "come on Craig, I know what chlorine is. My local pool totally smells like chlorine." But interestingly, your pool doesn't smell like chlorine. Aaa! Chloramine, which forms when chlorine reacts with organic substances, like the sweat oils, and urine, of swimmers. Gross. But true. Actually, the pool smell is typically an indication that the pool could use more chlorine. Anyway, when chlorine comes into contact with the hair and skin, they chemically bond. In other words, what happens when you go swimming in chlorinated water is that the chlorine bonds your hair, and it breaks down that sebum. As you can imagine, since sebum keeps hair moisturized, it dries it out. It even cracks the cuticle over time. See, again, I don't understand this, I'm bald.

If you consistently swim in chlorinated swimming pools, your hair might dry, fizz, or break. Sometimes you hear people talking about chlorine turning hair green, but that isn't technically the chlorine's fault. It happens when you dump green paint over your head. Also, it happens when the chlorine comes into contact with metal, like a pool's copper pipes. Then, the chlorine that bonds with hair actually brings some metal along with it, and that can temporarily turn light colored hair green. A good way to protect your hair before you go swimming is just to wash it in water, which minimizes the amount that chlorine can bond to it. Some pre-swim conditioner helps as well. Or a swim cap. Or just don't go swimming. Take a nap. You deserve it.

Thanks for watching Mental Floss on YouTube, which is made with the help of all these nice cuticles. Actually, that one's a follicle. If you have a big question of your own that you'd like answered, leave it below in the comments. See ya next week.  

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