The healthy scalp dry shampoo with light-as-air dry cleansing technology for scalp and hair that feel just washed without buildup or powdery residue. **OLAPLEX products are thoroughly tested in-house and by independent third-party laboratories for safety and efficacy. This product testing includes the industry standard Human Repeat Insult Patch Test (HRIPT), which tests for skin irritation or sensitivity. All of OLAPLEX products passed the HRIPT, meaning the products show no signs of causing irritation, inflammation, or sensitivity. **