14.1 Chemical Relaxing: Hydroxide, Thio, and Keratin

Chemical relaxing on the New Jersey theory exam

Quick Answer: NIC New Jersey Domain 2 (Hair Care and Services, 40 of 110 weighted items) tests chemical relaxing, restructuring, and curl reduction as hydroxide, thio, and keratin. N.J.A.C. 13:28-6.29 assigns Chemical Relaxing & Pressing 30 class hours + 60 practical hours = 90 hours. Hydroxide lanthionizes disulfide bonds; thio reduces them and then oxidizes them back. Never mix thio and hydroxide on the same hair unless a manufacturer-allowed rebuild or conversion system says you may. Scalp abrasions contraindicate the service. Pressing shares the NJ hour line as a thermal straighten; thermal irons themselves were Chapter 12.

The NIC New Jersey Cosmetologist-Hair Stylist written exam is 120 items / 110 weighted / 120 minutes. Domain 2 is the largest slice. Item 2.E.1 d is not a brand-name trivia line. It asks whether you can pick the right chemistry family, apply virgin versus retouch correctly, protect the scalp, stop the reaction the way that family requires, and refuse when the scalp or the fiber cannot take it. Chapter 7 already taught why thio and hydroxide are incompatible as chemistry. This section is the hair-care procedure that Domain 2 grades.

NJ curriculum hours: relaxing sits with pressing, not with the perm clock

Permanent waving is a separate 13:28-6.29 subject: 25 class + 90 practical = 115 hours (Section 14.2). Thermal curling and waving is another line (10 class + 35 practical = 45 hours) and belongs with Chapter 12 tools. Do not steal perm hours to explain a relaxer, and do not re-teach Marcel or ceramic irons here.

Pressing (hot comb or thermal press) temporarily straightens by rearranging hydrogen bonds with heat and tension. The pattern returns when hair is shampooed or takes on humidity. Chemical relaxing changes cortex disulfide chemistry so the fiber stays looser or straighter until it grows out. New Jersey schools clock them together because both are straightening services in one curriculum unit, not because a press is a hydroxide cream. If a Prometric stem says pressing, think thermal, temporary, hydrogen bonds. If it says relaxer, think permanent cortex change until new growth appears.

The Board does not publish a numeric pH cap for relaxer cream in N.J.A.C. Read pH, timing, and first aid on the product label and SDS. Textbook ranges below are teaching values, the same way Chapter 7 labeled acid-mantle pH.

Three CIB families: hydroxide, thio, keratin

Lye means sodium hydroxide (NaOH). It is fast, highly effective on resistant coil, and a high scalp-burn risk. Textbook charts often place sodium hydroxide relaxers around pH 12.5–13.5. That band is a textbook range, not a New Jersey statute.

No-lye usually means a hydroxide system that is not sodium hydroxide: commonly calcium hydroxide mixed with guanidine carbonate to form guanidine hydroxide, or lithium or potassium hydroxide. No-lye does not mean no alkali and does not mean safe on an abraded scalp. Some no-lye systems are marketed as milder on skin and can still dry the fiber and overprocess. If an exam stem treats no-lye as pH-neutral conditioner, the answer is wrong.

Thio relaxers use ammonium thioglycolate (or a related thio) at a higher concentration than a typical waving lotion. Textbook pH often sits near alkaline-perm territory (about 9–10 on many charts). Because bonds are reduced then oxidized, thio-straightened hair is not the same chemical object as hydroxide-lanthionized hair. Curl reduction and curl reformation (soft-curl systems) live in this thio family when the goal is a looser pattern rather than bone-straight hair. They still need analysis, timing, and a real oxidizer step.

HARD STOP: thio and hydroxide on the same hair

Do not apply a thio perm or thio relaxer over hydroxide-relaxed hair, and do not apply hydroxide over a thio service, unless the manufacturer's conversion or rebuild system expressly allows that sequence on that fiber. Lanthionized bonds are not waiting to be re-oxidized by perm neutralizer. Mixing families without that protocol causes extreme breakage, heat, and possible chemical burn. If the client cannot name the last cream — lye, no-lye, thio, or keratin iron — strand test and treat the hair as incompatible until proven otherwise. A signed release does not authorize a contraindicated mix.

Base cream, virgin application, and retouch

Base cream is a protective petroleum or similar barrier on the scalp, hairline, ears, and nape for base hydroxide services. It is not the relaxer, not a timing substitute, and not a license to scratch the scalp with the comb. No-base formulas carry more oily protection in the cream; you still follow the label. Drips on skin are wiped immediately. Burning, welting, or weeping means rinse and stop — you do not “push through” for straighter roots.

Virgin relaxer (first-time chemical straighten of those lengths):

• Analyze scalp integrity and elasticity before you open the jar.
• Curl is often most resistant mid-shaft; body heat makes the scalp zone process faster.
• Standard teaching: apply to resistant lengths first, typically about 1/4–1/2 inch away from the scalp (and often slightly off already-porous ends), smooth with the back of the comb without scraping, then bring product to the scalp area last for a shorter contact window — always per the manufacturer's diagram. Those distances are textbook procedure, not an N.J.A.C. measurement.
• Goal: even reduction without burning the scalp or mashing porous ends.

Retouch:

• Product goes on new growth only.
• Do not overlap previously relaxed hair. Overlap is the classic breakage at the line of demarcation.
• Timing is often shorter because the target band is short and sits in body heat.
• Do not “refresh” old lengths with a full hydroxide coat for shine.

Perform a strand test when history, color, or elasticity is questionable. A mushy, gummy strand is a stop, not a cue to add heat.

Neutralization: two different stop buttons

After thio relaxing you rinse, then apply the oxidizing neutralizer for the full directed time. That oxidizer rebuilds disulfide bonds in the new shape. Skipping it leaves the fiber weak and chemically open. Residual thio that was not rinsed will keep reducing while you think you are oxidizing.

After hydroxide you do not rebuild disulfide bonds with a perm oxidizer. You rinse until the cream is gone, then use the line's neutralizing shampoo to drop pH and remove alkali. Calling that shampoo “the same as perm neutralizer” is an exam fail. Chapter 7's pH story and this Domain 2 procedure are the same rule in two rooms: lanthionization is not reversed by hydrogen peroxide waving neutralizer.

Keratin as a CIB relaxing and restructuring category

NIC New Jersey lists keratin next to hydroxide and thio for relaxing, restructuring, and curl reduction. In the salon that usually means keratin smoothing, Brazilian-type blowouts, and related heat-sealed systems, not a sodium hydroxide cream. Results are often semi-permanent (they wash down over weeks to months) compared with hydroxide permanent lanthionization. Heat plus chemical still damages if you over-iron, over-process, or work on a broken scalp.

Published science and federal safety materials — not New Jersey Board numeric limits:

• Many smoothing products use formaldehyde, formalin, or methylene glycol. OSHA treats those names as formaldehyde under 29 CFR 1910.1048. When heated with a flat iron, formaldehyde can off-gas. OSHA's Hazard Alert on hair-smoothing products documented salon air samples and products labeled “formaldehyde-free” that still released formaldehyde.
• OSHA's formaldehyde permissible exposure limit is 0.75 ppm as an 8-hour time-weighted average, with a 2 ppm 15-minute short-term limit and a 0.5 ppm action level. Those are federal OSHA figures, not N.J.A.C. numbers and not a Prometric “New Jersey keratin ppm.”
• FDA warns that heated smoothing products can release formaldehyde gas; ventilation matters. FDA does not license New Jersey shops — that is the State Board of Cosmetology and Hairstyling plus OSHA workplace rules. A nationwide FDA formaldehyde-in-smoothing-products ban was proposed; teach the warning and SDS duty, not an invented in-force New Jersey product ban.
• Glyoxylic acid and related “formaldehyde-free” aldehyde chemistry (including glyoxyloyl carbocysteine systems) is common in newer smoothers. Published 2024 health-agency reports (including France's ANSES) associated some glyoxylic-acid straightening with acute kidney injury cases. That is published science, not a New Jersey case count and not a Board hour table. Read the SDS, ventilate, and do not promise “non-toxic” because the bottle says keratin.

Contraindications and a New Jersey chair

Scalp abrasions, open sores, fresh tracks from braids or weaves, contagious scalp disease, and non-elastic or already mushy hair contraindicate chemical relaxing. Alkaline cream on broken skin is a chemical-burn path. Poor elasticity is a breakage path. Unknown prior hydroxide versus thio is a conversion path. Metallic (progressive) dyes plus oxidizers can heat or melt fiber — refuse chemical texture on that history.

A Camden Saturday: the client wants “just a little more straight” on hair relaxed six weeks ago. You measure about 1/2 inch of new growth, you do not re-coat the lengths, you base as the product requires, you time from the strand test, and you stop if the scalp stings beyond ordinary warmth. That is Domain 2.E.1 d in a New Jersey shop: hydroxide, thio, or keratin — chosen, mapped, and stopped correctly — or not done today.

Exam traps

• Trap: No-lye means pH 7 and cannot burn. It is still a hydroxide-family alkali.
• Trap: A retouch is a whole-head shine refresh. Retouch is new growth only.
• Trap: Perm oxidizer rebuilds hydroxide-relaxed hair. Lanthionization does not reverse that way.
• Trap: Pressing and relaxing are the same chemical. Pressing is thermal and temporary on the NJ hour line.
• Trap: Keratin needs no ventilation because it is protein. Heated aldehyde systems still off-gas.

Aftercare that protects the 90-hour skill

Relaxed hair is permanently altered until it grows. Home care is moisture and gentle handling, not a weekly hydroxide “touch-up” on old lengths. Wait the manufacturer-directed interval before the next shampoo when the line requires it. Schedule the next retouch from regrowth, not from a desire to re-coat shiny mid-shafts. For keratin clients, teach wash rules, chlorine caution, and realistic longevity — and keep the salon ventilated while you iron. Implements still go through N.J.A.C. 13:28-3.2 disinfection after the chemical: an EPA-registered tuberculocidal product for the label contact time, or an FDA-registered autoclave. Chemistry on the hair does not excuse chemistry on the tools.