California Cosmetology Written ExamEyelash and Eyebrow ServicesMedium
A technician plans to perform an eyebrow tint using an aniline derivative dye. Per standard safety practice, how long before the service should a predisposition patch test be performed?
- AOne week before the service
- BImmediately before the tint is applied
- C24 to 48 hours before the service
- DA patch test is not required for eyebrow tinting
Show answer & explanationAnswer & explanation
Correct answer: C. 24 to 48 hours before the service
Aniline derivative tints can cause allergic reactions, so a small amount is applied to the skin (such as behind the ear or inner elbow) 24 to 48 hours before the actual service to check for sensitivity. If irritation occurs, the tint service must not be performed.
Why the other options are wrong
- A. One week is longer than necessary and not the standard timeframe used.
- B. Testing immediately before service does not allow enough time for a delayed allergic reaction to appear.
- D. A patch test is required due to the allergenic potential of aniline derivative tints.
Predisposition Patch Test
A skin test performed 24-48 hours before using aniline derivative tints to check for allergic reactions before full application.
- Applied behind ear or on inner elbow
- Client must wait full 24-48 hours before service
- Any redness, swelling, or itching means tint should not be used
Memory trick: Two days to test, before you dye the rest.