If you want to show how well your product protects hair from particulate pollution, then you may consider performing an anti-pollution test.

This test uses a custom-built pollution chamber that is able to deposit pollutant particles evenly, accurately and reproducibly over the surface of a number of tresses. The method evaluates the ability of test products to repel or clean particulate matter from the hair surface. A typical anti-pollution test involves measuring hair properties before product treatment, after product treatment, after pollution, and after cleansing again with the products. The levels of particle deposition can be measured using a colorimeter (hair greying) and with microscopy. Dry combing experiments can measure the effects of pollution on hair smoothness. Tests can be performed over single or repetitive pollution cycles.