Florida Cosmetology Licensing ExamHair ServicesHard
A client has decided to receive a chemical relaxer. During the hair analysis, the cosmetologist observes that the client's hair has been previously treated with a thio relaxer and is now exhibiting some breakage and dryness. Which type of relaxer should *not* be used on this client?
- AGuanidine hydroxide relaxer
- BLow-pH thio relaxer
- CSodium hydroxide relaxer
- DAmmonium thioglycolate (ATG) relaxer
Show answer & explanationAnswer & explanation
Correct answer: C. Sodium hydroxide relaxer
Sodium hydroxide relaxers are incompatible with thio relaxers due to their different chemical compositions and how they break the disulfide bonds. Mixing these relaxer types can lead to severe hair damage, breakage, and scalp irritation. It is critical to avoid using a sodium hydroxide relaxer on hair that has been previously treated with a thio relaxer.
Why the other options are wrong
- A. Guanidine hydroxide relaxers (no-lye) are generally considered safer and less damaging than lye-based (sodium hydroxide) relaxers, but still require careful consideration on previously relaxed hair.
- B. Low-pH thio relaxers are a milder form of thio relaxers and might be an option if the hair can tolerate it, but they are still in the thio family and not the 'forbidden' type.
- D. Ammonium thioglycolate (ATG) relaxers are the same chemical family as thio relaxers, so using another thio relaxer on previously thio-relaxed hair is generally acceptable if the hair condition allows, though caution is needed.
Relaxer Incompatibility
The principle that certain types of chemical hair relaxers cannot be used on hair previously treated with an incompatible relaxer type, due to severe risk of damage.
- Thio relaxers (ammonium thioglycolate) are incompatible with hydroxide relaxers (sodium hydroxide, potassium hydroxide, lithium hydroxide).
- Applying an incompatible relaxer can cause severe hair breakage, melting, and scalp burns.
- Always perform a thorough client consultation and hair analysis to determine previous chemical services.
Memory trick: THIO and HYDROXIDE: NEVER mix, or the hair will be a FIX (broken mess).