The presence of which substance in the hair structure can interfere with a perm and cause damage?

• A. Metallic Salts
• B. Water
• C. Alcohol
• D. Fragrance

Answer: (A)

Metallic salts in the hair can interfere with a perm because they react with the chemical processing agents used to break and reform the hair’s bonds. These metal ions come from mineral-rich water, certain hair products, or previous chemical treatments that left metal residues in the strand. When the perm solution, which is designed to reduce disulfide bonds, meets these metal ions, the reaction can become unpredictable—causing uneven processing, excessive swelling or breakdown in spots, heat buildup, and ultimately hair damage. Because of this potential interference, it’s important to assess for mineral or metal deposits and use appropriate prep steps (like chelating shampoos or strand tests) before attempting a perm. Water, alcohol, and fragrance don’t chemically interfere with the perm process in the same way metallic salts do.