Hints & Tips

Metallic Salts Test

Incompatibility Test

Some products that a client may have used on their hair can react badly to chemicals used within the salon. These typically include hair colour restorers, which leave behind a chemical residue of metallic salts that can cause hair to turn green, steam or break off when combined with hydrogen peroxide or similar.

Often a client will forget or fail to mention the use of a product, and in the context of hair restorers the terminology implies that hair is truly restored to its original colour; this is obviously not the case!

If the previous use of a chemically based product is suspected, or there is a possibility that a previous treatment hasn't been removed, use the following test:

  • Mix 40ml of 20 volume (6%) hydrogen peroxide with 2ml of ammonia
  • Cut a few hair samples from the client's head (make sure this is from the suspected area) and hold them together with cotton or sticky tape
  • Place the hair samples in the solution and leave for up to 30 minutes

If the hair has changed colour or bubbles have formed, or if the solution is warm, do not proceed with any hairdressing process that contains hydrogen peroxide.


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