California Cosmetology Written ExamHaircoloringMedium
Per manufacturer safety guidelines for aniline derivative tints, how long before the actual color service should a predisposition (patch) test be performed?
- AOnly after an allergic reaction occurs
- BOne week before application
- C24 to 48 hours before application
- DImmediately before application
Show answer & explanationAnswer & explanation
Correct answer: C. 24 to 48 hours before application
Manufacturer instructions for aniline derivative tinctures (containing PPD) require a predisposition/patch test 24 to 48 hours before each application to detect potential allergic reactions.
Why the other options are wrong
- A. Testing must occur before application, not reactively after a reaction.
- B. One week is longer than the manufacturer-required window.
- D. Testing immediately before does not allow time for a reaction to develop.
Patch (Predisposition) Test
A skin test performed 24-48 hours before applying aniline derivative tint to check for allergic sensitivity to PPD.
- Required before each new color application
- Tests for PPD allergy reaction
- Positive test = redness, itching, swelling - do not proceed
Memory trick: Two days' wait keeps allergies at bay.