Is Hair Coloring Unhealthy?

We all know that looking our best can go a long way toward feeling our most confident. And if you’re like many women, you also know that a new style and hair color are both great ways to refresh your overall look. While you probably think about the time, energy and money that goes into having your hair colored, you might not consider whether or not color is unhealthy for you or your hair. And if you dig deep enough into research on the topic, you’ll find that there is a lot of conflicting information out there about the potentially negative effects of hair dyes on your hair and your body. Here, we’ll try to cut through the clutter and address a few myths, considerations and alternative options to help you figure out what’s best for your own health when it comes to hair color chemicals. 
What’s that smell?
We’ve all breathed it in it at some point when walking into a salon... that nose-scrunching, chemical smell that tends to make our eyes water. That smell means there is some permanent hair coloring going on in your local beauty shop--and it helps to understand what’s in those dyes and exactly how the process works. At the risk of sounding like Bill Nye the Science Guy, here’s a closer look at how hair color and chemical dyes work. (Don’t worry, there won’t be a pop quiz!)
  • Hair is made up mostly of keratin, a protein found in our fingernails and skin, too. The color of your hair is made up of one of two other proteins: eumalanin, if you have brown or black hair, or phaeomelanin for blonde, ginger and red hues. The absence of these two proteins results in hair that’s gray or white. 
  • Women and men alike have been coloring their hair for thousands of years using natural pigments like henna, or shells from walnuts. These natural pigments coat the shaft of the hair and typically rinse off after just a few washes.
  • Temporary or semi-permanent hair dyes coat the hair with acidic dyes or consist of tiny pigment particles that slip inside the hair. These will eventually wash out with shampooing. Also, because the hair isn’t opened up in these processes, the natural color of the hair will remain underneath the new hue.
  • Lightening is achieved by using bleach or hydrogen peroxide. Bleach oxidizes the color proteins in the hair leaving them colorless. The catch is that this process is irreversible and can result in some unnatural, odd colors. More often, hydrogen peroxide is used in an alkaline solution that opens up the hair cuticle and allows the peroxide to react with the color protein.
  • Permanent hair dyes work by getting inside the outer shaft of the hair, removing the natural color (similar to lightening), and depositing the new color pigment. There are a few different chemical processes all happening at the same time to achieve this. Ammonia is used to open the cuticle and jumpstart the peroxide, oxidizing the natural color. The new pigment then bonds to the inside of the hair, and finally, conditioners help to seal the hair again and lock in the color. As for the pungent smell, when the peroxide reacts with the proteins inside the hair it releases sulfur--and that coupled with the ammonia is STINKY!
So, what does this mean for my hair?
The key to a great hairstyle is to have it look marvelous without a ton of maintenance. When it comes to color, a permanent dye definitely offers more longevity and less upkeep. But what about all those chemical processes we just read about? Should you be worried? We’ve explored six common concerns below:
1.Can hair coloring make my hair fall out?
It’s important to remember that every body is different, and there are many different hair types as well. That said, there is no hard evidence that permanent hair coloring causes hair loss. A bad color job can cause hair to dry out and create breakage that can be confused with hair loss, however. Thoroughly conditioning your hair before and after coloring goes a long way to prevent your hair from becoming brittle and breaking. Another factor that can lead to confusion on this topic is that over a lifetime there is a certain amount of hair loss that occurs naturally. Many times this natural hair loss coincides with graying hair and more frequent trips to your stylist. 
2. Will coloring my hair thin it out?
Similar to hair loss, there is a certain amount of thinning that happens naturally over time and it’s not hard for the blame to jump to regular coloring. However, dying hair adds a layer of pigment that many people find actually thickens how their hair looks and feels. If hair loss and thinning are becoming a problem, it’s a good idea to forgo the coloring for a bit and determine whether it’s due to a specific reaction to the chemical dye or an underlying problem like thyroid issues, anemia or another medical problem. Always consult with your primary care physician if you have health concerns.
3. What can I do to prevent hair coloring from drying my hair?
Because of chemical processing, overly-dry hair that’s prone to breakage can be an unfortunate side effect of regular colorings at the salon. There are some simple steps that can help overcome this issue:
  • Always use moisturizing shampoo and conditioner.
  • Apply a deep conditioning hair mask before and after coloring, and as often as needed in between colorings.
  • Use a leave-in conditioner before blow drying and be careful not to over-dry or over-brush your hair.
  • Consider supplements that include biotin and vitamin A.
4. Does coloring my hair increase my risk for cancer?
The short answer is that studies have not been able to consistently link an increased risk of cancer to those who use permanent hair dyes regularly. The International Agency for Research on Cancer considers personal hair dye use to be “not classifiable as to its carcinogenicity to humans,” based on a lack of evidence from studies in people. This is a tricky one though. There have been a couple of studies linking hair dyes to bladder cancer in lab mice, plus most studies of people exposed to hair dyes at work, such as stylists and barbers, have found a small but fairly consistent increased risk of bladder cancer.
5. Could I be allergic to hair color?
Yes, a number of substances in hair dyes can cause allergic reactions in a small percentage of people. The most common is 4-ParaPhenyleneDiamine (PPD), a substance that reacts with peroxide within the chemical dye. The allergies can result in a simple red rash around the hairline to itching, swelling and, at times, more severe skin irritations. The simplest way to avoid an allergic reaction is by using a patch test beforehand. Here are four simple steps to conducting a patch test at home: 
  • Determine the type and color of hair dye that you wish to use. Open the package and pour a few drops of color and an equal amount of developer to a small bowl. Mix with a toothpick.
  • Dunk a Q-tip in the solution and apply a quarter-sized dab to the inside of your elbow.
  • Cover the dab with a bandage so it doesn’t rub off on clothing. Remove the bandage after 30 minutes but don’t wash off the solution.
  • Keep a close eye on the spot for the next 48 hours. If you see any signs of redness or itchiness, wash the area with warm, soapy water -- and don’t use that hair dye!
When making an appointment with a stylist, have the stylist conduct a patch test 48
hours before your appointment to make sure you don’t have any allergic reactions.
6. Are there permanent, natural hair coloring options available?
There are plenty of natural hair coloring products out there, but because they don’t use chemicals to open up the hair cuticles, most tend to be semi-permanent and will wash out eventually. Still, a quick Google search will turn up a handful of alternatives that may work better for you and your hair. Specifically, if you are more chemically sensitive or have naturally thin or dryer hair, taking a good look into natural hair dyes is a great idea.
Now that you know how hair dyes work, and the considerations you should take into account before coloring your hair, you’ll feel more confident in not just your hairstyle, but your hair coloring choices, too.

American Cancer Society, "Hair Dyes,", accessed on May 17, 2013.
American Osteopathic College of Dermatology, "Allergic Contact Dermatitis,", accessed on May 17, 2013.
WebMD, "Hair Dye Allergies on the Rise,", accessed on May 17, 2013.
Cleveland Clinic, "Hair Disorders,", accessed on May 17, 2013.