Facts on Hair Coloring

When hair is colored, it opens the cuticle layer of the hair, which then allows molecules of color to enter the cortex of the hair shaft. Once the color has entered the cortex, it expands to a size that cannot be eliminated simply by washing. Hair specialists treat colored hair with products of specific pH levels between 3.5 and 6, moisture levels and hydrolyzed protein to help the colored hair maintain color for an extended period of time. There are three different types of hair color: temporary, semi-permanent and permanent. Temporary color washes out with each shampoo. Semi-permanent color washes out after about eight shampoos and permanent color will typically last until the hair grows out. If hair color is applied incorrectly, it can cause the hair to break and become brittle and dry.

Color Fade

Shampoos and conditioners that contain salicylic acid, coal tar, sulfur or selenium sulfide can make colored hair fade. Wearing a hat in the sun, using a leave-in conditioner and periodically deep conditioning color-treated hair can help maintain and extend the color and help keep it from fading.

Coloring Gray Hair

When coloring gray hair, a semi-permanent color is the best choice as gray hair is often colored frequently. A permanent color, used on a frequent basis, can cause hair to break and become damaged.

Tipping, Frosting and Streaking

Tipping usually involves bleaching the tips of hair and then dying them a different color. Some people choose to leave the tips bleached. Frosting is when a cap is worn and strands of hair are pulled through small holes in the cap to be bleached. Streaking requires the use of a brush to apply color or bleach to the hair.

Natural Ingredients

Some hair-coloring products use minimal chemicals and rely more on natural ingredients such as walnut extracts, cinchona extracts, henna and rhubarb to produced the desired effect of hair coloring.

Allergies

Many people experience allergic reactions to the chemicals used in hair dyes. Aniline dyes, which are made from coal tar, dyes that contain p-Phenylenediamine -- also known as PPD, ammonia and hydrogen peroxide can all cause serious allergic reactions. Some hair dyes also use mercury or lead, which can cause allergic reactions.

Cancer Risks

The World Health Organization has stated in 2008 that there is evidence of a link between hair dyes and bladder cancer. However, this increased risk of suffering bladder cancer is related to barbers and hairdressers who work with the hair dye chemicals on a regular basis. There is little evidence to support the claim that having hair dyed can cause bladder cancer or any type of blood cancer.

Resources

• Dr. Lawrence Samuels