Study guide
3.5 Chemical Texture Services
Cosmetology State Board Exam Exam
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1 Introduction to the Cosmetology State Board Exam
1.1 About the Cosmetology State Board Exam 1.2 NIC vs State-Specific Exams 1.3 Exam Content Breakdown 1.4 How to Register and What to Expect 1.5 How to Use This Study Guide
2 Chapter 2: Scientific Concepts (35% of NIC Exam)
2.1 Infection Control & Sanitation 2.2 Bacteriology 2.3 Anatomy & Physiology - Skin 2.4 Anatomy & Physiology - Hair & Nails 2.5 Chemistry for Cosmetology 2.6 Electricity & Safety
3 Hair Care and Services
3.1 Hair Analysis and Consultation 3.2 Shampooing and Conditioning 3.3 Haircutting Fundamentals 3.4 Hairstyling and Finishing 3.5 Chemical Texture Services 3.6 Hair Coloring
4 Skin Care & Esthetics
4.1 Skin Analysis & Consultation 4.2 Facial Treatments 4.3 Hair Removal 4.4 Makeup Application
5 Chapter 5: Nail Care
5.1 Nail Anatomy & Disorders 5.2 Manicure Services 5.3 Pedicure Services 5.4 Nail Enhancements 5.5 Nail Art & Finishing
6 Chapter 6: State Licensing Requirements
6.1 How State Licensing Works 6.2 Training-Hour Requirements Across States 6.3 Exam Components: Theory and Practical 6.4 Application, Background Checks & Fees 6.5 Reciprocity, Endorsement & License Transfer 6.6 Renewal and Continuing Education 6.7 Scope of Practice & License Types 6.8 State Sanitation Rules & Discipline 6.9 Multi-State Comparison & Relocation Guide
7 Chapter 7: New York Cosmetology Exam
7.1 About the New York Cosmetology Exam 7.2 New York State Laws & Regulations 7.3 NY Written Exam Content 7.4 NY Practical Exam 7.5 NY-Specific Practice Questions
8 Chapter 8: Florida Cosmetology Exam
8.1 About the Florida Cosmetology Exam 8.2 Florida State Laws & Regulations 8.3 Florida Salon Requirements 8.4 FL Theory Exam Content 8.5 FL Clinical Exam Content 8.6 FL-Specific Practice Questions
9 Chapter 9: Test Strategies
9.1 Test-Taking Strategies 9.2 Preparing for the Written Exam 9.3 Preparing for the Practical Exam 9.4 Exam Day Checklist 9.5 Comprehensive Practice Questions 9.6 Final Review Checklist
3.5 Chemical Texture Services
Key Takeaways Explain This Topic AI
Chemical texture services work by breaking and reforming disulfide bonds in the cortex
Alkaline (cold wave) perms are best for resistant hair; acid perms are gentler for damaged hair
NEVER mix hydroxide and thio relaxers - severe damage will result
Hydroxide-relaxed hair can NEVER be permed; thio-relaxed hair can receive a perm later
- Always apply relaxer retouch only to new growth - overlapping causes breakage
- Last updated: January 2026
Chemical texture services permanently change the hair's internal structure to create curl (permanent waves) or straightness (relaxers). These services alter disulfide bonds in the cortex and require thorough understanding for the NIC exam.
The Science of Chemical Texturing
Hair contains different types of bonds:
- Bond Type Strength What Breaks It Relevance to Styling
- Hydrogen bonds Weak Water, heat Wet setting, thermal styling (temporary)
- Salt bonds Weak pH changes Affected during chemical services
- Disulfide bonds Strong Only chemicals Permanent waves, relaxers (permanent change)
Chemical texture services work by:
- Breaking disulfide (sulfur) bonds in the cortex
- Reshaping hair into new configuration (curly or straight)
- Reforming bonds in the new shape through neutralization
- Permanent Wave Theory
A permanent wave (perm) adds curl to straight or wavy hair by chemically restructuring the hair.
The Perm Process:
- Step Chemical Action What Happens
- Processing Reducing agent (thio) Breaks disulfide bonds; softens hair
- Rinsing Water Removes excess waving solution
- Neutralizing Oxidizing agent (H₂O₂) Reforms and hardens disulfide bonds in new shape
- Types of Permanent Waves
Perm Type pH Active Ingredient Processing Best For
Alkaline (Cold Wave) 9.0-9.5 Ammonium thioglycolate (ATG) Room temp; no heat Resistant, coarse hair; strong curl
- True Acid 4.5-7.0 Glyceryl monothioglycolate (GMTG) Requires heat Fragile, damaged, porous hair; soft curl
- Acid-Balanced 7.8-8.2 GMTG with buffering Some need heat Damaged hair; gentle processing
- Exothermic Varies Thio + activator Self-heating Resistant hair; faster processing
- Endothermic Varies Various Requires external heat Heat-activated processing
- Low-Thio/No-Thio Varies Cysteamine hydrochloride Varies Allergies to thio; sensitive clients
- Perm Rod Selection
The size and type of rod determines curl pattern:
- Rod Size Diameter Curl Result Best For
- Small (Gray, Blue) Smallest Tight, defined curls Short hair, strong curl desired
- Medium (Pink, Purple) Medium Classic curl Average hair length, versatile
- Large (White, Yellow) Largest Loose waves, body Long hair, soft wave
Specialty Rods:
- Rod Type Shape Result
- Concave Smaller diameter in center Even curl distribution
- Straight Same diameter throughout Consistent curl from scalp to ends
- Spiral Long, uniform Corkscrew curls
- Loop/Circle Bendable Custom shapes, spot perms
- Perm Wrapping Techniques
- Technique Method Result
- Croquignole (Overlap) Wrap from ends to scalp Tighter at ends, looser at scalp
- Spiral Wrap in spiral along rod Even curl from root to end
- Piggyback/Double Two rods per section (ends + roots) Even curl on long hair
- Weave Skip strands in wrapping Partial curl, texture
- Hair Relaxers
Relaxers permanently straighten curly or coiled hair by breaking disulfide bonds and reforming them in a straight configuration.
Types of Relaxers
- Relaxer Type pH Active Ingredient Characteristics
- Sodium Hydroxide (Lye) 11.5-14 Sodium hydroxide (NaOH) Strongest; fastest; most effective; can irritate scalp
No-Lye (Calcium Hydroxide) 9.0-11 Calcium hydroxide + guanidine carbonate Gentler; good for sensitive scalps; can cause dryness
Lithium/Potassium Hydroxide Varies Lithium or potassium hydroxide Alternative hydroxide options
Thio Relaxer 9.0-10 Ammonium thioglycolate (higher concentration than perms) Requires neutralization with oxidizer; can be reversed
Hydroxide vs. Thio Relaxers
- Feature Hydroxide Relaxers Thio Relaxers
- Disulfide bonds Permanently broken (lanthionization) Broken but can reform
- Neutralization Plain water + acid-balanced shampoo Oxidizing neutralizer (H₂O₂)
- Can be re-permed? NO - never Yes, hair can receive perm later
- pH range 11.5-14 (lye) / 9-11 (no-lye) 9.0-10
- Compatible with? Only hydroxide relaxers Only thio relaxers
CRITICAL SAFETY RULE: NEVER mix hydroxide and thio products on the same hair. This causes severe damage and breakage.
Relaxer Application Process
Virgin Relaxer Application:
- Analyze hair and scalp; perform strand test
- Apply protective base to scalp (lye relaxers) or skip (no-base formulas)
- Section hair into four quadrants
- Apply relaxer to most resistant area first (usually nape)
- Apply 1/4 to 1/2 inch away from scalp, 1/2 inch from ends
- Smooth with back of comb (do NOT scratch scalp)
- Process according to strand test and manufacturer directions
- Rinse thoroughly with warm water
- Shampoo with neutralizing/acid-balanced shampoo
- Condition thoroughly
Retouch Application:
- Apply only to new growth (1/4 inch from scalp to line of demarcation)
- NEVER overlap onto previously relaxed hair
- Overlapping causes extreme damage and breakage
- Safety Precautions for Chemical Services
Before Service:
- Complete client consultation and history
- Perform strand test
- Perform patch test (color services)
- Check for contraindications (scalp irritation, recent services, metallic dyes)
- Wear protective gloves
During Service:
- Follow manufacturer's instructions exactly
- Monitor processing time carefully
- Check for signs of irritation or damage
- Maintain proper ventilation
- Never apply heat unless specified
After Service:
- Rinse thoroughly
- Apply appropriate neutralizer/conditioner
- Document service on client card
- Provide home care instructions
- Contraindications for Chemical Texture Services
- Contraindication Why Action
- Damaged/Over-processed hair Cannot withstand chemicals Refuse service; recommend conditioning
- Scalp irritation/abrasions Chemical burn risk Wait until healed
- Metallic dyes present Dangerous reaction Do NOT perform service
- Recent chemical service Overlapping damage Wait appropriate time
- Low elasticity Hair will break Refuse service
- Positive strand test Hair damaged during test Do NOT proceed
- The Neutralization Process
Neutralization is the final step that reforms and locks disulfide bonds in their new configuration.
For Perms:
- Blot excess solution from rods
- Apply neutralizer (usually contains hydrogen peroxide)
- Process for 5-10 minutes
- Remove rods carefully
- Apply remaining neutralizer to ends
- Rinse thoroughly
For Hydroxide Relaxers:
- Rinse thoroughly with warm water
- Shampoo with neutralizing (acid-balanced) shampoo
- This normalizes pH and helps close cuticle
- No oxidizing neutralizer needed
For Thio Relaxers:
- Rinse thoroughly
- Apply oxidizing neutralizer
- Process according to directions
- Rinse again