NIC Cosmetology Written (Theory) ExamHair Care and ServicesHard
A cosmetologist is preparing to perform a chemical texture service on a client whose hair has been previously colored with a permanent hair color. What is the most critical pre-service test to perform to ensure the hair's integrity and prevent damage?
- AElasticity test
- BPatch test
- CMetallic salt test
- DPorosity test
Show answer & explanationAnswer & explanation
Correct answer: C. Metallic salt test
When hair has been previously colored, especially if the client is unsure of the product history, a metallic salt test is crucial. Metallic salts, found in some progressive haircolors or color restorers, are incompatible with most chemical texture services and can cause severe damage, heat, and discoloration when combined with waving or relaxing solutions.
Why the other options are wrong
- A. An elasticity test assesses the hair's ability to stretch and return, which is important for overall hair health, but a metallic salt test specifically identifies a dangerous incompatibility.
- B. A patch test (predisposition test) is for allergic reactions to the chemical product, not hair integrity with previous treatments.
- D. A porosity test assesses the hair's ability to absorb moisture, which is important but not the most critical for preventing damage from *previous chemical treatments*.
Metallic Salt Test
A pre-service test to determine if hair contains metallic salts, which are incompatible with chemical texture services.
- Performed on a strand of hair placed in a mixture of peroxide and ammonia.
- If metallic salts are present, the hair will lighten rapidly, give off an odor, and/or get hot.
- Presence of metallic salts means chemical texture services should not be performed.
Memory trick: Colored hair and chemical waves, metallic salts mean danger saves.