5.1 Chemical Texture Services (Permanent Waving & Relaxers)

Chemical Texture Services: Permanent Waving and Relaxers

Chemical texture services allow barbers to permanently alter the natural wave pattern of a client’s hair, creating curls or straightening. Understanding the underlying chemistry is crucial for safety, predictability, and achieving high-quality results.

The Structure of Hair and Chemical Bonds

Hair is composed of keratin, a fibrous protein made of amino acid chains linked by peptide bonds. Polypeptide chains are cross-linked by three types of side bonds:

1. Hydrogen Bonds: Physical side bonds easily broken by water or heat that reform as the hair dries.
2. Salt Bonds: Physical side bonds broken by changes in pH that reform when the hair's natural pH (~4.5 to 5.5) is restored.
3. Disulfide Bonds: Strong, covalent side bonds that require a chemical reaction to break and reform. They link sulfur atoms in neighboring chains, and altering them is the core mechanism of chemical texture services.

Chemistry of Permanent Waving

Permanent waving involves physical wrapping and chemical waving solution and neutralizer via a reduction reaction (adding hydrogen). The waving solution breaks disulfide bonds by adding a hydrogen atom to each sulfur atom, separating the sulfur-sulfur bond.

Active Waving Agents

Waving solution strength is determined by reducing agent concentration.

• Ammonium Thioglycolate (ATG): The active ingredient in alkaline permanent waves. It combines thioglycolic acid with ammonia, which swells the cuticle to let the thioglycolic acid penetrate the cortex.
• Glycerol Monothioglycolate (GMTG): The primary reducing agent in acid-balanced and true acid waves. It has a lower pH, penetrates the hair slowly, and often requires external heat.

Types of Permanent Waves

• Alkaline Waves (Cold Waves): pH of 9.0 to 9.6. Uses ATG and processes at room temperature. Best for coarse, thick, or resistant hair.
• True Acid Waves: pH of 4.5 to 7.0. Uses GMTG and requires heat. Best for damaged, fine, or color-treated hair.
• Acid-Balanced Waves: pH of 7.8 to 8.2. Uses GMTG and processes at room temperature. Best for normal to fine hair.
• Exothermic Waves: Heats chemically via an activator, speeding up processing. Suited for coarse, resistant hair.
• Ammonia-Free and Thio-Free Waves: Ammonia-free waves use AMP or MEA for less odor. Thio-free waves use cysteamine.

Permanent Waving Wrapping Patterns

• Croquignole Wrap: Hair is wrapped ends to scalp in overlapping layers, creating a tighter curl at the ends.
• Spiral Wrap: Hair is wrapped at an angle, creating corkscrew curls from roots to ends.
• Basic Perm Wrap: A rectangular sectioning pattern where all rods move in the same direction.
• Bricklay Perm Wrap: Rods are positioned in an offset, staggered pattern to prevent splits.
• Curvature Perm Wrap: Rods follow the head's natural curves to blend sections.

Chemistry of Chemical Hair Relaxers

Types of Chemical Relaxers

• Sodium Hydroxide (Lye) Relaxers: pH of 12.5 to 14.0. Highly alkaline, breaks disulfide bonds permanently through lanthionization (converting disulfide bonds to single-sulfur lanthionine bonds). Once treated, hair cannot be permed or re-relaxed with thio products.
• Guanidine Hydroxide (No-Lye) Relaxers: pH of 13.0 to 13.5. Requires mixing. Gentler on the scalp but dries the hair shaft and can cause calcium buildup.
• Ammonium Thioglycolate (Thio) Relaxers: pH of 9.6 to 10.0. Uses ATG. Compatible with perms but completely incompatible with hydroxide relaxers.

[!WARNING] Hydroxide and thio chemical services are chemically incompatible. Applying a thio-based product to hair previously treated with a hydroxide relaxer (or vice versa) will cause severe chemical reactions, leading to hair disintegration, melting, and extreme breakage.

Neutralizing: The Oxidation Reaction

After the waving or relaxing solution has completed its work, the hair must be neutralized. In permanent waving and thio relaxing, the neutralizing process is an oxidation reaction.

The neutralizer—typically a low-concentration hydrogen peroxide solution (pH 2.5 to 3.5)—is applied after rinsing. The oxygen combines with the added hydrogen atoms, removing them to form water, allowing sulfur atoms to reform their covalent bonds.

For hydroxide relaxers, the neutralization step is different. Because hydroxide relaxers convert disulfide bonds to lanthionine bonds, an oxidizing neutralizer is not used. Instead, the hair must be rinsed thoroughly with warm water, followed by an acid-balanced neutralizing shampoo (typically pH 4.5 to 5.5) to neutralize the residual high alkalinity in the hair and scalp, bringing the pH back down to its natural range.

Application Procedures and Safety Precautions

1. Predisposition and Strand Testing: Perform a thorough analysis of the client’s hair porosity, elasticity, texture, and density. Inspect the scalp for any open wounds, scratches, or diseases. Never apply chemical solutions if the scalp is compromised.
2. Metallic Salt Test (1:20 Test): To test, mix 1 ounce of 20-volume developer with 20 drops of 28% ammonia. Place a strand of the client's hair in the solution for 30 minutes. If metallic salts are present, the hair will lighten rapidly, boil, smell foul, or disintegrate. Do not perform chemical services if this occurs.
3. Protective Cream & Draping: Always apply a protective base cream around the client’s hairline, ears, and neck to prevent chemical burns on the skin. Use a chemical cape and double-toweling to protect the client’s clothing and skin from chemical runoff.
4. Rinsing and Blotting: In permanent waving, rinse the waving solution for at least 5 minutes with warm water, then thoroughly blot each rod with a towel before applying the neutralizer. Excess water left on the rods will dilute the neutralizer, resulting in weak curls.