Chemical Chemistry & pH
This type of permanent wave has a pH between 9.0 and 9.6 and processes at room temperature without added heat.
Alkaline (or Cold) Wave
The innermost layer of the hair shaft that is sometimes missing in fine or blonde hair and plays no role in chemical texture services
Medulla
In permanent waving, this tool directly determines the size of the curl.
The perm rod
Commonly referred to as "lye relaxers," this chemical compound is the oldest and most common type of hydroxide relaxer.
Sodium hydroxide
If you observe these during a scalp analysis, you must immediately refuse to perform any chemical service.
Scalp abrasions, lesions, or open sores (or diseases)
The active reducing agent or primary ingredient found in most alkaline permanent waves.
Ammonium Thioglycolate (ATG)
These weak, physical side bonds are broken easily by water or heat and reform as the hair dries.
Hydrogen Bonds
This end-paper wrapping technique uses one paper placed under and one paper placed over the strand of hair being wrapped.
Double flat wrap
Guanidine hydroxide relaxers are commonly advertised as "no-lye" relaxers and require mixing these two components prior to application.
Relaxer cream + activator
Hair that has been treated with this type of metal-containing product will fizz, heat up, or break if perm solution is applied
Metallic salts or compound dyes
Acid-balanced waves process faster and produce firmer curls than true acid waves because they fall within this pH range.
Accept: 7.8–8.5
The hair’s ability to absorb moisture, which directly dictates the processing time and strength of chemical formulations needed.
Porosity
Wrapping hair tight at a 45-degree angle beyond perpendicular to its base section produces this specific type of base placement.
On base placement
To protect the client’s scalp from irritation or chemical burns, this petroleum-based product is applied to the hairline, ears, and scalp prior to a hydroxide relaxer.
Base cream or protective base
To test for the presence of metallic salts before perming, you can immerse a strand of hair in a mixture of 20-volume peroxide and 20 drops of this chemical
Ammonia
Hydroxide relaxers are not compatible with thio relaxers because they permanently remove a sulfur atom from a disulfide bond in this chemical process.
Lanthionization
These strong chemical side bonds account for about one-third of the hair's overall strength and can only be broken by chemical agents like perms or relaxers.
Disulfide bonds
Unwinding a perm rod 1.5 to 2 turns during processing to inspect the formation of an "S" pattern is called this.
A test curl
During a virgin relaxer application, the chemical is applied first to these zones, avoiding the scalp and porous ends until the middle section processes.
The mid-shaft (1/2 inch away from scalp) up to the ends
You should never perform a thio perm on hair that has previously been treated with this category of chemical relaxer.
Hydroxide Relaxer
The primary chemical ingredient found in most perm neutralizers that rebuilds disulfide bonds by removing hydrogen.
Hydrogen Peroxide
Before applying a chemical service, you test a hair strand’s ability to stretch and return to its original length without breaking to determine this property.
Elasticty
This wrapping method involves wrapping the hair from the ends straight down to the scalp in overlapping concentric layers.
A croquignole or straight wrap
To check if the hair has reached the desired level of straightness during processing, the stylist performs this test using the back of a comb or fingers.
Scrape test or smooth test
The mandatory test performed 24 to 48 hours prior to a chemical service if a client shows signs of sensitivity or allergic reaction.
Patch or predisposition test