Why Does Ammonia Hair Color Cause Breakage?

Men and women turn to hair dyes to experiment with a new look or hide grays. Colorists recommend touching up dyed hair every four to six weeks, as hair begins to grow out and reveal its natural pigment. Constantly subjecting hair to the harsh chemicals present in many dyes, however, will damage the hair shaft and cause breakage. Ammonia is one particular ingredient in permanent dyes that can compromise the health of your hair.

Identification

• Ammonia is an alkaline, or basic, substance with the chemical symbol NH3. The three hydrogen atoms and one nitrogen atom that make up ammonia form a gaseous or liquid substance that is highly soluble in water, colorless and strong-smelling. In the past, ammonia was utilized as smelling salts to revive fainting victims. The chemical now is used in household cleaners, fertilizers and hair dyes. Ammonia on the skin can cause a burning sensation, while inhaling it can actually lead to fainting, according to the Wise Geek website.

Function

• Permanent hair dyes work by chemically opening the outer layer of the hair shaft and depositing color in the core of the strand. The human hair cuticle resembles the scales of a fish. Ammonia causes the hair shaft to swell, which forces the scales of the cuticle to separate slightly. The peroxide can then penetrate the core of the hair shaft and change the pigment within. The amount of ammonia in hair dyes is usually less than 1 percent in concentration, according to the Chemical and Engineering News website.

Effects

• Repeatedly dyeing your hair with mixtures that contain ammonia will damage the hair cuticle. Ammonia is corrosive, which means that it will wear away at the hair shaft. Under a microscope, hair that has been treated with ammonia will start to resemble Swiss cheese, according to the Organic Color Systems website. With the health of the cuticle compromised, the strand is less able to withstand stress and is more likely to break.

Considerations

• Not only does ammonia in hair dyes cause breakage, it also damages the core of the strand. Ammonia causes hair color to fade by damaging the natural protein within the strand, called tyrosine. Tyrosine is an amino acid that produces melanin, which in turn colors your hair, according to the Organic Color Systems website. Damaged Tyrosine reduces the hair's ability to maintain its natural pigment.

Prevention and Solution

• Semi-permanent and natural hair dyes do not contain ammonia, but still deliver results. Semi-permanent dyes color the outside of the hair shaft rather than penetrating the core. This results in less damage to the hair, but the color also will fade away after several washings. Some people use natural ingredients to change their hair color. Lightening agents include lemon juice and vinegar, while henna and black walnut shells will coat the hair shaft in pigment much like semi-permanent dyes.