Discover how to perform an incompatibility test process on the hair before a chemical service in the essential MHD testing video tutorial. You will explore why an incompatibility test checks for the presence of metallic salts, and when to perform the test with MHD Instructor Tracey Sajno. If metallic salts are present in the hair and a chemical service is applied, the results can be quite severe and may lead to hair disintegration.

It is important to follow the manufacturer's instructions when carrying out these tests.