11.2 Permanent Waving: Alkaline, Acid & Non-Thio Systems

A permanent wave wraps hair around a rod, uses a labeled reducing waving lotion to break enough disulfide bonds for the fiber to take that rod’s shape, rinses, then oxidizes (neutralizes) so new disulfide bonds form in the curl. The NIC theory outline groups waving/texturizing as alkaline, acid, and non-thio. Oklahoma’s Board-administered practical currently lists a mock chemical-wave kit rather than a live thio pour: you still have to wrap, barrier, glove, and apply as if the bottle were waving lotion. This section is the written chemistry plus that practical choreography.

Alkaline / cold waves (ammonium thioglycolate)

The textbook alkaline wave or cold wave uses ammonium thioglycolate (ATG) in a lotion typically near pH 9.0–9.6. Alkalinity swells the cortex and lifts the cuticle so ATG can reduce disulfide bonds without a hood dryer in the classic procedure—hence “cold.” These waves process faster on resistant, coarse, or low-porosity hair than a mild acid wave would. The tradeoff is more cuticle lift and more risk on porous, color-treated, or already-stretched hair. If the stem says untreated resistant hair and no added heat, ATG/alkaline is the usual match—if the manufacturer’s strength and timing fit, which OAC 175:10-7-3 still requires you to take from the label, not from salon folklore.

Acid, acid-balanced, and true acid waves (GMTG family)

Most acid waves and acid-balanced waves use glyceryl monothioglycolate (GMTG) as the reducer. GMTG as a chemical is acidic; the working lotion’s pH depends on the activator and formula.

True acid waves are commonly taught in the pH 4.5–7.0 neighborhood. They usually require heat (endothermic) because the lower pH opens the cuticle less. They are the gentler theoretical choice for color-treated or porous hair when the label says so—not because “acid” means harmless, but because swelling and speed are lower.

Acid-balanced waves are often taught slightly above 7 (a common teaching band is about 7.8–8.2). They still swell less than a pH 9+ cold wave. Many modern “acid perms” in kits are acid-balanced rather than truly acidic. Exam stems that say pH below 7 plus heat want true acid. Stems that say slightly alkaline GMTG, less swell than ATG want acid-balanced.

Acid-wave components are often taught as waving lotion, activator, and neutralizer. Mix only as labeled. GMTG can be a sensitizer; gloves and ventilation are part of the service, not optional extras.

Exothermic versus endothermic

Exothermic waves create heat inside the mixed product by a chemical reaction (often when an activator is added). That self-heating helps processing. You still time by the label and by test curls, not by whether the cap feels warm.

Endothermic waves need heat from outside—typically a hood dryer. True acid waves are the usual endothermic story. If a stem says “requires an outside heat source,” choose endothermic. If it says “heat is produced in the product when mixed,” choose exothermic. Do not confuse either word with “thio-free.”

Non-thio / thio-free systems (including cysteamine)

NIC lists non-thio waving/texturizing as its own example class. Textbook and manufacturer families include cysteamine, some sulfite, and other labeled thio-free reducers. They still aim at disulfide rearrangement and still need the labeled neutralization or stop step. They are not a loophole that lets you perm hydroxide-relaxed hair, skip a patch or strand check the label requires, or mix the bottle with a hydroxide cream. Teach them as another reducer family you identify from the ingredient list and SDS, then use exactly as directed. Oklahoma has not published a separate “cysteamine exception” in OAC Title 175; 175:10-7-3 (mix as labeled, ventilate, original containers) still governs the bottle.

Rods, wrap, and papers—shape is physical; bonds are chemical

Rod diameter controls curl size. A smaller rod yields a tighter curl; a larger rod yields a looser wave. Length, density, and how much hair you load on the rod matter, but diameter is the first multiple-choice lever. Wrap direction and base placement control volume and how the curl sits:

• On-base: hair is held 45 degrees forward of the perpendicular and the rod sits on its base—more volume.
• Half off-base: 90 degrees from the head—moderate volume, a common default teaching wrap.
• Off-base: 45 degrees down, rod off the base—less volume, less base lift.

Croquignole wrapping winds from the ends toward the scalp in overlapping layers, the classic medium-length perm wrap. Spiral wrapping winds along the length of the rod, used for longer hair when you want the curl to follow the rod like a spring.

End papers control the last inch of hair so ends are smooth on the rod. Without them, ends buckle into fishhooks. A bookend wrap folds one end paper around the strand like a book cover. A double-paper wrap uses a paper on each side of the hair. Double-tool (piggyback) wrapping uses two rods on one long panel so the scalp portion and the lengths each have a rod to wrap on—conceptually how you keep long hair from stacking so thick that the inner hair never processes.

Sectioning, clean partings, even tension, and not stretching dripping hair into a thinner rod than the length can handle are how you avoid broken hair at the rubber band. Band the rod without indenting the hair; a tight band is a breakage line, not extra curl.

Test curl, underprocessing, overprocessing

A test curl is how you read reduction before you rinse and neutralize. Unwind a rod about one and a half to two turns, without pulling the hair straight, and look for a fully formed S-pattern that holds. If the hair is still too straight or the S is weak, processing is incomplete (underprocessed): too few disulfide bonds reduced. Options then follow the label—more time, or heat if the system allows—not a surprise dump of a stronger leftover bottle.

Underprocessed hair after neutralization looks too straight or too loose for the rod that was used. Bonds were not opened enough to take the shape; an oxidizer “locked” a shape that never formed. Overprocessed hair had too many disulfide bonds reduced. Wet, it may look overly curly or overly soft; dry, it often goes limp, frizzy, or mushy because there is not enough intact cystine left to rebuild a strong curl. Elasticity fails. You cannot safely “fix” overprocessing with more waving lotion. You cut, condition, and wait for growth.

Timing starts when the lotion is applied as the manufacturer directs (often after the wrap is complete for many alkaline waves; always follow that product). Porous hair drinks lotion faster. Body heat at the scalp can process the nape and crown differently than the lengths—another reason for test curls in more than one area when the label or hair condition warrants it.

Neutralizer goes on after a thorough water rinse of waving lotion, with the hair usually still on the rods. Blot excess water so you do not dilute the oxidizer into nothing. Apply, process for the labeled time, rinse, then carefully remove rods.

Oklahoma Board practical: chemical-wave kit (mannequin, mock product)

OSBCB administers the practical; Prov does not. The Board’s cosmetology exam page (supplies list, page last modified August 7, 2025) tells candidates to use a mannequin head (no live models). For the chemical-wave portion it lists:

• 2 white, 2 grey, and 2 pink rods — no 1/2 rods
• 1 all-purpose or tail comb (non-metal)
• Spray bottle for water
• Clips or clamps
• Cotton strip (protective barrier)
• End papers
• Towels
• Chemical cape
• Applicator bottle with water for mock application
• Disposable protective gloves

Bring those colors and counts. Do not substitute a drawer of 1/2-inch rods the Board told you not to bring. The list does not publish a brand’s diameter chart for white versus grey versus pink; diameter still controls curl, and the Board controls which rods you may unpack. Mock application means water in the applicator, not a live ATG pour on the exam floor. Procedure still looks like a chemical service: chemical drape, gloves, cotton barrier at the hairline so product (even water, in muscle memory) is not running onto skin, even saturation of the wrapped sections, and infection-control habits from earlier chapters.

Non-metal combs matter around chemical services: metal can react with waving products and can also be uncomfortable or damaging if you are scraping a coated rod. Keep the chemical cape as a waterproof client-protection drape, not a cutting cape you “already had on.”

Practice the wrap until end papers sit clean, bands are not cutting, and you can glove-and-cotton without fishing for supplies. Theory items will still ask ATG versus GMTG. The practical will ask whether your kit matches Oklahoma’s list.

Read the chart as relative aggressiveness of cuticle lift, not as a license to skip the SDS. A true acid wave near 6 still reduces disulfide bonds. An alkaline wave near 9 still needs a timed rinse and oxidizer. Thio relaxers sit a step more alkaline than a cold wave in this teaching picture; they are the next section’s curl-reduction chemistry, not a perm you wrap on pink rods for volume.