Porosity of Hair

Porosity of hair is the ability of the hair to absorb liquid or moisture. It is important when doing any sort of chemical treatment that the hair is not overly porous as it can soak up the chemicals too quickly and damage the hair.

If the hair does not have the same porosity over the entire head, some areas will process too fast. An easy test for porosity is to take a lock of hair and let it float on water for two minutes. If it floats, the outer layer is healthy. If it sinks, the outer layer is too open and will allow chemicals to absorb too quickly—in this case don't process with any chemicals until treated with the proper reconstructors.