← Chemical Services – Texas Cosmetology State Board Exam

Texas Cosmetology State Board Exam Study Guide

Key concepts, definitions, and exam tips organized by topic.

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Chemical Services – Texas Cosmetology State Board Exam

Comprehensive Study Guide


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Overview


Chemical services are among the most technically demanding and regulated procedures in cosmetology. This guide covers permanent waving, chemical relaxers, hair color theory, hair lightening, and chemical safety as tested on the Texas Cosmetology State Board Exam. Mastery of chemical reactions, pH levels, bond chemistry, and safety protocols is essential for both the exam and safe professional practice.


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Section 1: Permanent Waving


How Permanent Waves Work


Permanent waving is a two-step chemical process that restructures the hair's internal bonds to create a lasting curl pattern.


  • • Step 1 – Reduction: The waving solution breaks disulfide bonds in the hair's cortex, softening the hair so it can be reshaped around a rod.
  • • Step 2 – Oxidation (Neutralization): The neutralizer re-forms the disulfide bonds in their new curled position, locking in the shape.

    • Types of Permanent Wave Solutions


    | Type | pH | Key Ingredient | Best For |

    |---|---|---|---|

    | Alkaline (Cold Wave) | 8.2–9.6 | Ammonium thioglycolate (ATG) | Normal/resistant hair |

    | True Acid Wave | 4.5–7.0 | Glyceryl monothioglycolate | Color-treated/damaged hair |

    | Acid-Balanced Wave | 7.0–8.2 | Glyceryl monothioglycolate | Sensitized hair |

    | Exothermic Wave | Varies | ATG + activator | Resistant hair (self-heating) |


    Key Concepts


  • • Ammonium thioglycolate (ATG): The primary reducing agent in alkaline waves; breaks disulfide bonds
  • • Exothermic wave: Generates its own heat through a chemical reaction when activator is mixed with waving lotion — no external heat source needed
  • • Pre-wrap lotion: Applied before winding to equalize porosity so the solution processes evenly from roots to ends
  • • Rod size rule: Smaller rods = tighter curls; larger rods = looser waves

    • Test Curl Interpretation


    | Appearance When Unwound | Diagnosis |

    |---|---|

    | Firm, defined "S" pattern | Properly processed |

    | Weak, loose "S" that doesn't hold | Under-processed — needs more time |

    | Limp, mushy, "fishhook" shape | Over-processed — too many bonds broken |


    Key Terms

  • • Disulfide bonds – Strong sulfur-to-sulfur bonds in the cortex that give hair its strength and shape
  • • Reduction – The chemical process of breaking disulfide bonds using a reducing agent
  • • Oxidation – The chemical process of re-forming disulfide bonds during neutralization
  • • Neutralizer – The solution that stops waving action and re-oxidizes disulfide bonds
  • • Exothermic – A reaction that releases heat (contrast: endothermic absorbs heat)
  • • Pre-wrap lotion – A solution applied to equalize uneven porosity before wrapping

    • > Watch Out For:

    > - The neutralizer performs oxidation, not neutralization in the pH sense — the name is misleading

    > - Acid waves require heat to process (endothermic); exothermic waves generate their own heat

    > - Over-processing is irreversible — damaged disulfide bonds cannot be re-formed

    > - Never apply permanent wave solution to hydroxide-relaxed hair — causes extreme breakage


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    Section 2: Chemical Relaxers


    How Relaxers Work


    Chemical relaxers permanently straighten hair by breaking and restructuring the disulfide bonds in the cortex through a process called lanthionization.


    Types of Relaxers Compared


    | Type | Active Ingredient | pH | Notes |

    |---|---|---|---|

    | Lye (Sodium Hydroxide) | Sodium hydroxide | 12–14 | Fast-acting; requires protective base |

    | No-Lye (Guanidine) | Guanidine hydroxide | 9–11 | Less scalp irritation; leaves hair drier |

    | Thio Relaxer | Ammonium thioglycolate | 9.0–9.5 | Gentler; used on coarse Caucasian/Asian hair |


    The Lanthionization Process (Hydroxide Relaxers)


    1. The highly alkaline relaxer swells the hair shaft and enters the cortex

    2. Disulfide bonds are broken and converted into lanthionine bonds

    3. Lanthionine bonds are permanent and cannot be reversed — hair is permanently straightened


    Application Types


  • • Virgin application: Relaxer is applied to the entire hair shaft for the first time
  • • Retouch application: Relaxer is applied only to new growth (regrowth near the scalp), avoiding previously relaxed hair to prevent over-processing

    • The Relaxer Service Process


    1. Apply protective base cream (petrolatum) to scalp and hairline

    2. Section hair and apply relaxer, beginning 1/4 inch from scalp

    3. Process and check for straightening

    4. Rinse thoroughly with warm water

    5. Apply neutralizing shampoo to stop the chemical action and restore pH to 4.5–5.5

    6. Condition the hair


    Key Terms

  • • Sodium hydroxide (lye) – Active ingredient in lye relaxers; pH 12–14
  • • Guanidine hydroxide – Active ingredient in no-lye relaxers; formed by mixing guanidine carbonate + calcium hydroxide
  • • Lanthionization – The process of converting disulfide bonds to lanthionine bonds
  • • Lanthionine bonds – New bonds formed by hydroxide relaxers; permanent and irreversible
  • • Protective base cream – Petrolatum-based barrier applied before sodium hydroxide relaxers
  • • Neutralizing shampoo – Stops relaxer action and restores hair to its natural acidic pH
  • • Retouch – Relaxer application to new growth only

    • > Watch Out For:

    > - Lye and no-lye relaxers are not interchangeable in the same service — mixing causes severe breakage

    > - The neutralizing shampoo in relaxer services restores pH (it's actually acidic), unlike the perm neutralizer which performs oxidation — do not confuse the two

    > - Sodium hydroxide relaxers cannot be followed by a thio perm — bond incompatibility causes breakage

    > - Never apply relaxer to abrasions, cuts, or open sores on the scalp


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    Section 3: Hair Color Theory


    The Four Categories of Hair Color


    | Category | Longevity | Lifts? | Contains Peroxide? | Molecule Size |

    |---|---|---|---|---|

    | Temporary | Shampoo to shampoo | No | No | Largest (coats cuticle) |

    | Semi-Permanent | 4–6 weeks | No | No | Medium (deposits only) |

    | Demi-Permanent | 4–6 weeks | No | Yes (low volume) | Small (penetrates slightly) |

    | Permanent | Permanent | Yes | Yes | Smallest (penetrates cortex) |


    Developer (Hydrogen Peroxide) Volume Guide


    | Volume | Concentration | Lift | Common Use |

    |---|---|---|---|

    | 10-volume | 3% | 1 level | Deposit only / toning |

    | 20-volume | 6% | 1–2 levels | Standard permanent color |

    | 30-volume | 9% | 2–3 levels | High-lift or resistant gray |

    | 40-volume | 12% | 3–4 levels | Maximum lift (off-scalp only) |


    The Law of Color


  • • Primary colors: Red, Yellow, Blue
  • • Secondary colors (mix two primaries):

    • - Red + Yellow = Orange

    - Yellow + Blue = Green

    - Red + Blue = Violet

  • • Complementary colors (opposites on the color wheel — neutralize each other):

    • - Red neutralizes Green

    - Blue neutralizes Orange

    - Violet/Purple neutralizes Yellow


    The Level System


    Hair color is measured on a 1–10 scale (1 = black, 10 = lightest blonde). Understanding levels is essential for predicting color results and selecting the correct formula.


    Contributing Pigments (Undertones) During Lifting


    | Level | Undertone Revealed |

    |---|---|

    | 1–3 | Black/Dark Brown |

    | 4–5 | Brown/Red-Brown |

    | 6 | Red-Orange/Orange-Red |

    | 7 | Orange |

    | 8 | Orange-Yellow |

    | 9–10 | Yellow/Pale Yellow |


    Single-Process vs. Double-Process Color


  • • Single-process: Lightens and deposits color in one step using permanent color + developer
  • • Double-process: Step 1 — prelighten with bleach; Step 2 — apply toner or color to achieve final result

    • Standard Mixing Ratio


  • • Most permanent colors: 1:1 (color : developer)
  • • Some formulas: 1:2 — always follow manufacturer's instructions

    • Key Terms

  • • Oxidative color – Hair color that requires hydrogen peroxide (aniline derivative)
  • • Developer – Hydrogen peroxide; activates color and lifts natural pigment
  • • Contributing pigment – The underlying warm tone revealed when natural hair is lightened
  • • Complementary colors – Opposite colors on the color wheel that neutralize each other
  • • Level – The measurement of lightness or darkness of hair color
  • • Tone/Hue – The color or pigment (warm, cool, neutral)

    • > Watch Out For:

    > - Blue neutralizes orange (brassy highlights), violet/purple neutralizes yellow — memorize these pairs

    > - Demi-permanent color contains low-volume peroxide but does not lift — it only deposits

    > - The standard mixing ratio is 1:1, but always verify with manufacturer guidelines

    > - Patch tests are required for oxidative (aniline derivative) colors — not temporary colors


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    Section 4: Hair Lightening (Bleach)


    How Lighteners Work


    Hair lighteners (bleach) use hydrogen peroxide combined with persulfate boosters (ammonium, potassium, or sodium persulfate) to oxidize and dissolve melanin in the cortex. No artificial color is deposited.


    Types of Lighteners


    | Type | Application | Strength |

    |---|---|---|

    | Cream lightener | On-scalp or off-scalp | Moderate |

    | Powder lightener | Off-scalp only | Strongest |

    | Oil lightener | On-scalp | Mildest |


    > ⚠️ Powder lightener is NEVER used on the scalp — it can cause severe chemical burns.


    The Seven Stages of Decolorization


    Hair passes through these stages progressively as melanin is oxidized:


    1. Black

    2. Brown

    3. Red

    4. Red-Orange

    5. Orange

    6. Yellow

    7. Pale Yellow


    Each stage must be reached progressively — you cannot skip stages.


    Toners


  • • A toner is a semi-permanent or demi-permanent color applied to pre-lightened hair
  • • Applied when hair has reached pale yellow (level 9–10)
  • • Neutralizes unwanted warm tones and achieves the desired final shade (ash, beige, platinum, fashion shades)
  • • Blue/violet-based toners cancel brassiness and yellow tones

    • Key Terms

  • • Persulfate salts – Boosters in powder lighteners that accelerate bleaching
  • • Decolorization – The process of oxidizing and removing melanin from the hair
  • • Toner – A low-volume color applied after lightening to refine the final shade
  • • On-scalp lightener – Cream or oil lightener formulated for scalp use
  • • Off-scalp lightener – Powder lightener; must never touch the scalp

    • > Watch Out For:

    > - You must reach pale yellow before toning — applying toner too early yields muddy results

    > - Lightener should never be used on hairpieces or wigs (especially synthetic)

    > - The seven stages go in order — there are no shortcuts

    > - Toners use 10-volume developer in most cases — not high-volume


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    Section 5: Chemical Safety & Client Protection


    The Patch Test (Predisposition Test)


  • • What: A small amount of oxidative color applied to the inner arm or behind the ear
  • • When: 24–48 hours before any oxidative (aniline derivative) color service
  • • Why: To detect allergic reactions (contact dermatitis) before full application
  • • Required for: All permanent, demi-permanent, and semi-permanent oxidative colors

    • > ⚠️ If a client shows any sign of reaction (redness, swelling, itching), do NOT perform the service.


    The Strand Test


  • • What: Processing a small section of hair with the proposed chemical
  • • Purpose: Predicts timing, color result, and hair integrity before the full service
  • • When: Before any chemical service, especially on compromised hair

    • Contraindications for Chemical Services


    A cosmetologist must refuse service if any of the following are present:


  • • Scalp abrasions, cuts, or open sores
  • • Signs of scalp disease or infection
  • • Positive patch test reaction
  • • Incompatible previous chemical services (e.g., thio + hydroxide relaxer)
  • • Severely damaged or over-processed hair

    • Chemical Incompatibility — Critical Rule


    | Previous Service | Cannot Follow With |

    |---|---|

    | Hydroxide relaxer (NaOH, guanidine) | Thio perm or thio relaxer |

    | Lye relaxer | No-lye relaxer (same service) |

    | No-lye relaxer | Lye relaxer (same service) |


    Reason: Hydroxide relaxers convert disulfide bonds into lanthionine bonds, which cannot react with thio solution. The result is extreme breakage and potential complete hair loss.


    Emergency Procedures


    | Situation | Action |

    |---|---|

    | Chemical in client's eyes | Flush immediately with large amounts of cool water for 15+ minutes, then seek medical attention |

    | Chemical burn on scalp/skin | Rinse thoroughly with cool water; seek medical attention |

    | Allergic reaction | Stop service, rinse product, document, refer to physician |


    Safety Data Sheets (SDS)


  • • Formerly called: MSDS (Material Safety Data Sheet)
  • • Required by: Texas law — all salons must maintain SDS for every chemical product
  • • Contains: Ingredients, hazards, first aid measures, safe handling, storage, and disposal information
  • • Purpose: Protects both cosmetologists and clients from chemical hazards

    • Personal Protective Equipment (PPE)


  • • Gloves: Chemical-resistant gloves required for ALL chemical services
  • • Apron: Protective apron recommended
  • • Eye protection: Required when mixing or applying certain chemicals
  • • Client draping: Cape and neck strip to protect clothing and skin

    • Texas Client Records Requirements


    Before performing any chemical service, the following must be completed and retained in the client's file:


  • • Client consultation
  • • Signed release/informed consent form
  • • Patch test results (for color services)
  • • Documentation of any contraindications

    • Key Terms

  • • Patch test – Pre-service skin test for aniline derivative color allergies (24–48 hours prior)
  • • Strand test – Pre-service test on a hair section to predict results
  • • SDS (Safety Data Sheet) – Required chemical hazard documentation
  • • PPE – Personal Protective Equipment
  • • Contraindication – A condition that prevents a service from being safely performed
  • • Informed consent – Client's signed acknowledgment of service risks

    • > Watch Out For:

    > - The patch test must be performed 24–48 hours before the service — not immediately before

    > - Never put neutralizing solutions or other chemicals in a client's eyes — water only

    > - SDS sheets must be on-site and accessible at all times in a Texas salon

    > - Thio and hydroxide chemistry are completely incompatible — this is a frequent exam topic

    > - A signed consent form does NOT override safety contraindications


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    Quick Review Checklist


    Use this checklist to confirm you are exam-ready:


    Permanent Waving

  • • [ ] Know that ATG (ammonium thioglycolate) is the reducing agent in alkaline waves
  • • [ ]
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