Hair coloring products that contain metallic salts are not compatible with

• A. Thio relaxers
• B. Lye relaxers
• C. Guanidine relaxers
• D. Ammonia-treated dyes

Answer: (A)

Metallic salts left in hair color introduce metal ions into the hair, and those ions can react with the thioglycolate reducing agent used in thio relaxers. That interaction disrupts the relaxing chemistry, leading to unpredictable results such as uneven processing or hair damage. Because of this, hair coloring products containing metallic salts are not compatible with thiol-based (thio) relaxers. The other relaxer systems use different chemistry, so the primary incompatibility highlighted here is with thio relaxers.