All About Hair Tests

At Freshair, the most important thing to us is to keep our customers happy and safe. If you’ve been a regular customer with us for a while now, chances are you may have been asked to have a test or two in your time. But what are they and why do we do them? Read on to learn all about our tests and how they ensure that you stay safe.

All tests are noted on the individual client’s record card for future reference.


Skin / Patch test (allergy alert test)

One of the most common tests – the skin or patch test is used for customers wishing to dye or perm their hair. Many dyes include the chemical paraphenylenediamine (PPD), whereas perming involves ammonium thioglycolate. Sometimes, skin can be sensitive to these chemicals, so a patch test ensures no negative reaction will occur during the process.

Every manufacturer recommends slight amendments to the standard skin test, however this is an overview.

During this test we will:

• Apply a small amount of the product on the skin – normally behind the ear or the inner elbow.

• Let it dry

• Ask you not to clean it for 45 minutes

• Allow a period of 48 hours to elapse before the full service takes place, to ensure no negative reaction will occur.

Strand testing

This test is not necessary for routine services, but is worth doing for new clients, complex hair treatments or changes in colouring. The strand test will simply test a strand or two of your hair, under the same chemicals that will be eventually going over your full hair. This will allow us to know how your hair will react, and indicate the amount of chemical/dye necessary for the desired results or colour.

During this test we will:

• Take a few strands of hair from an inconspicuous place

• Subject the strand to the same chemicals / dyes as are intended for your hair service

• Monitor the results

Incompatibility test

The incompatibility test checks for metallic salts and other incompatible chemicals that may be present on your hair. Metallic salts can occur due to using some home dyes or living in properties with old copper piping; if you have home dyed your hair or know that you have copper pipes, let us know. This test will be carried out prior to a chemical service, like a perm, to ensure the hair will safely take the necessary chemicals.

During this test we will:

• Cut a small piece of hair off

• Place the hair sample in a mixture of peroxide and perm solution

• Leave the sample for around 20 minutes

• Check for a reaction such as bubbling or fizzing – if a reaction occurs it may be that it is not safe to carry out a chemical service.

Elasticity Test

During this test we check the strength of your hair. Ideally, healthy hair should stretch about 30% and then recoil back to it’s original length. You can rate hair elasticity as either ‘good’ or ‘poor’.

During this test we will:

• Take a few strands of your hair and mist with water

• Pull on your them gently so that they stretch

• Release the hair

Porosity Test

This test checks the cuticle layers of the hair. If they are raised or suffer damage the hair will tend to look dry or frizzy and absorb more moisture – like chemicals or products. If the cuticle scales are damaged in some areas but not in others, it could lead to an uneven finish.

During this test we will:

• Hold some strands of hair and move our thumb and forefinger up and down the hair.


• Take a clean strand of hair and put into a container of water. Floating hair indicates low porosity, sinking hair means high porosity.

If there is damage, the hair will feel rough to the touch; in this case you may need to think about some repairing or soothing conditioning treatments to rectify the damage.

Make sure you book a consultation if you’re planning on changing your colour, or if you’ve changed medication, as both these will require a test to ensure your safety.

As always, we’re here to help! So If you have any question, don’t hesitate to get in touch with our friendly team. We recommend having a consultation prior to any complex treatments, just to ensure you get the look you’re after!

Posted on Apr 26, 2021