Chương 4 / 515% của kỳ thi

Chemical Services

Shampooing & Conditioning

Shampoo cleanses the hair and scalp of dirt, oil, and product buildup.
Conditioners and acid-balanced rinses help close the cuticle and detangle the hair.
Natural hair and skin are slightly acidic, about pH 4.5 to 5.5 (the acid mantle).
On the pH scale, 7 is neutral; below 7 is acidic and above 7 is alkaline.

Chemical Texture Services

Relaxers break disulfide bonds to straighten curly or coiled hair, then are neutralized.
Perms break and then reform disulfide bonds around rods to create curl.
The neutralizer (fixative) reforms the bonds and locks in the new shape.
Apply a protective base cream to shield the scalp from caustic relaxer chemicals.

Haircolor Basics

Permanent (oxidation) color deposits color in the cortex for a lasting change.
Hydrogen peroxide is the developer that lifts natural pigment and develops color.
Temporary and semi-permanent colors coat or lightly penetrate and fade with shampooing.
Highly alkaline products swell and open the cuticle, which can weaken hair if overdone.

Safety, Testing & Allergies

Perform a patch (predisposition) test 24 to 48 hours before aniline-derivative color.
Do not proceed if the client reacts to the patch test; advise them to see a physician if needed.
Use a strand test to preview color result, timing, or curl before treating the whole head.
Assess porosity, since porous hair absorbs chemicals and color faster, affecting timing.
Kiểm tra kiến thức của bạn
Câu hỏi luyện tập về Chemical Services
Luyện tập ngay →

Last updated: July 2026

Báo lỗi