California Cosmetology Written ExamSafety and Infection ControlHard
A client requests an aniline derivative tint service for the first time at a salon. According to standard safety practice supported by California cosmetology law, what must the cosmetologist do at least 24 to 48 hours before the service?
- APerform a predisposition (patch) test on the client's skin to check for allergic reaction
- BApply a strand test using bleach instead of the tint formula
- CHave the client sign a general liability waiver only
- DApply the full-strength dye directly to the scalp as a trial run
Show answer & explanationAnswer & explanation
Correct answer: A. Perform a predisposition (patch) test on the client's skin to check for allergic reaction
Aniline derivative tints can cause severe allergic reactions in sensitive individuals. A predisposition (patch) test must be performed 24-48 hours before the first use of the product, applying a small diluted amount behind the ear or on the inner elbow, to check for a reaction before full application.
Why the other options are wrong
- B. A strand test checks color result/processing, not allergic sensitivity, and uses bleach for a different purpose.
- C. A waiver does not substitute for the required physical allergy screening.
- D. Full-strength application without testing risks a dangerous allergic reaction.
Predisposition (Patch) Test
A skin test performed 24-48 hours before an aniline derivative tint service to detect potential allergic reactions before full chemical application.
- Small diluted product amount applied behind ear or inner elbow.
- Must wait 24-48 hours and check for redness, itching, or swelling.
- Required before every new aniline dye service, even for repeat clients using a new product.
Memory trick: 'Test first, tint later' — 24-48 hour wait before full color application.