2.2 Salon Chemistry, Electricity & Safety

2.2 Salon Chemistry, Electricity & Safety

The Texas operator exam treats chemistry as the "why" behind every chemical service. If you understand pH and oxidation-reduction (redox), you can answer color, perm, relaxer, and lightener questions without memorizing each product.

Matter and Mixtures

Matter is anything that occupies space; it exists as solid, liquid, or gas. Salon products are usually mixtures: a solution (sugar/salt water — fully dissolved, stable), a suspension (calamine, glitter polish — particles separate and need shaking), or an emulsion (cream conditioner, color cream — two unmixable liquids held together by a surfactant/emulsifier). A pure substance is a single element or compound, while a physical mixture can be separated without a chemical change.

The pH Scale

pH (potential hydrogen) measures how acidic or alkaline a water-based solution is on a scale of 0 to 14:

The scale is logarithmic: each whole number is a tenfold change. A pH of 9 is ten times more alkaline than 8 and one hundred times more alkaline than 7 — a favorite exam calculation. Skin and hair are mildly acidic (the acid mantle, pH 4.5–5.5). Acidic products contract and harden the cuticle (smoothing, shine); alkaline products soften and swell it, opening the cuticle so chemicals can enter.

Oxidation-Reduction (Redox)

Redox is the chemistry behind color and perms. Oxidation is the addition of oxygen (or loss of hydrogen); reduction is the loss of oxygen (or addition of hydrogen). The two always happen together: when one substance is oxidized, another is reduced.

• Permanent haircolor and lighteners use hydrogen peroxide developer as the oxidizing agent. Developer strength is measured in volume: 10 volume (3%) for low lift, 20 volume (6%) for one to two levels of lift and gray coverage, 30 volume (9%) and 40 volume (12%) for greater lift. Higher volume = more oxygen released = more lift, but more damage.
• Lightening (bleaching) oxidizes and diffuses melanin through ten stages, lifting hair from black through brown, red, orange, gold, to the palest yellow.
• Permanent waving works in two redox steps. The waving lotion (alkaline ammonium thioglycolate, or acid glyceryl monothioglycolate) is a reducing agent that breaks the hair's disulfide bonds. After the rod-wrapped hair is reshaped, the neutralizer (an oxidizer such as hydrogen peroxide or sodium bromate) re-forms the disulfide bonds in the new curl shape. Skipping or under-timing the neutralizer leaves limp, weak curls — a classic troubleshooting question.
• Chemical relaxers break the same disulfide bonds: sodium hydroxide (lye) relaxers (pH up to ~13.5) and milder no-lye (guanidine/ammonium thioglycolate) relaxers.

Electricity and Modalities

Electricity flows as a current through a conductor. Direct current (DC) is constant and one-directional (batteries); alternating current (AC) reverses direction (wall outlets). Key terms: volt = pressure, ampere (amp) = strength/quantity, ohm = resistance, watt = how much energy is used per second. A fuse or circuit breaker prevents overloading.

Facial modalities are currents used in treatments:

Electrical and Chemical Safety, SDS, and Ergonomics

• Inspect cords; never use a frayed cord or touch electrical equipment with wet hands. Use a GFCI outlet near water and unplug by gripping the plug, not the cord.
• A Safety Data Sheet (SDS) must be on file for every chemical the salon uses; TDLR/OSHA require it accessible. The SDS lists ingredients, hazards, handling, storage, first aid, and disposal.
• Provide adequate ventilation for fumes (color, acrylics, monomers); store flammables away from heat; keep chemicals in labeled, closed containers.
• Ergonomics: keep wrists straight, work at the correct chair/table height, and alternate posture to prevent repetitive-strain and carpal-tunnel injuries.

Color Theory and Product pH in Practice

Because alkaline products swell the cuticle, permanent color (pH around 9–10, mixed with peroxide) penetrates the cortex and lasts; semi-permanent and demi-permanent colors sit closer to neutral and fade gradually because they only coat or lightly penetrate. Hydroxide relaxers cannot be neutralized by an oxidizer — they require an acid-balanced neutralizing shampoo to lower the pH and stop the action, while thio relaxers are rinsed and neutralized like a perm. Mixing relaxer types or using the wrong neutralizer is a tested error.

Acids, Alkalis, and First Aid

Knowing pH guides safety. Strong alkalis (hydroxide relaxers near pH 13.5) cause chemical burns and severe scalp irritation; strong acids can also burn. If product contacts the eye, flush with cool water for at least 15 minutes and refer for medical care — never neutralize an eye splash with another chemical. Always perform a patch (predisposition) test 24–48 hours before applying aniline-derivative permanent color to screen for allergic reaction, and a strand test to preview color result and processing time.

Salon Chemistry Quick Reference

Common Exam Traps

• Peroxide oxidizes; perm waving lotion reduces — match the action to the reaction.
• A pH change of one whole number is a tenfold, not a one-unit, change.
• 40 volume developer gives the most lift but the most damage; never assume "stronger is better."
• An SDS, not a sales receipt or client form, is the required hazard document for every chemical.
• Sanitizing only reduces germs; disinfection is the minimum salon standard for reusable nonporous tools.