Texas Cosmetology Operator Written ExamHair Care ServicesHard

A cosmetologist is performing a hair coloring service on a client who previously had her hair colored with metallic dyes. What is the primary concern and potential risk when applying oxidative hair color over hair treated with metallic dyes?

  1. AThe new color will not penetrate the hair shaft.
  2. BA severe chemical reaction, discoloration, or hair breakage may occur.
  3. CThe hair will appear dull and lifeless after coloring.
  4. DThe metallic dyes will cause the hair to become overly porous.
Show answer & explanation

Correct answer: B. A severe chemical reaction, discoloration, or hair breakage may occur.

Metallic dyes contain metal salts that can react severely with the hydrogen peroxide in oxidative (permanent or demi-permanent) hair colors, leading to extreme heat, chemical burns, or severe hair damage and unpredictable discoloration.

Why the other options are wrong

  • A. While penetration can be affected, the primary and most dangerous concern is a chemical reaction.
  • C. Dullness is a possible negative outcome, but it is secondary to the more severe risks of chemical reaction and damage.
  • D. Metallic dyes can make hair feel coated, but the main issue isn't increased porosity, it's the dangerous chemical interaction.

Metallic Dyes & Oxidative Color

Applying oxidative hair color over hair previously treated with metallic dyes can cause a dangerous chemical reaction due to the interaction of metallic salts with hydrogen peroxide.

  • Metallic dyes are progressive, building up color with each application.
  • Contain lead, silver, copper, which react with peroxide.
  • Always perform a strand test and metallic salt test before applying oxidative color.

Memory trick: METALLIC + OXIDATIVE = MELTDOWN!

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