All About Hair Porosity
What is porosity?
Porosity is the ability of a material to absorb and hold moisture. It is also a quality indicator of a material’s tendency to allow moisture to penetrate its membrane. When it comes to hair, porosity can be helpful in determining what products will be most efficient as a conditioner. Hair porosity is largely determined by genetics, though it can be affected by external factors such as heat and chemicals.
Other examples of materials with varying degrees In materials like wood, marble, cement, sponge or rock, porosity levels are taken to determine the percentage of open pockets of air (or pores) on the material’s outer-most surface, and based on that, its ability to absorb and retain moisture.
A sponge is an example of a porous material as it has a large percentage of empty spaces covering its outer surface, whereas granite is an example of a material that it less porous (lower porosity) and doesn’t soak up water as easily.
Hair porosity, however, can differ much more from person to person than it does from sponge to sponge or slab of granite to slab of granite. An individual’s porosity level is determined by the molecular structure of the hair cuticle, which is the outermost, membrane-like layer of the hair shaft.
Low v. high porosity hair
Low porosity hair is characterised by a molecularly-tight bound outer layer that makes it difficult for moisture to penetrate and escape the hair shaft. Low porosity hair often takes a long time to dry, is resistant to colouring and other chemical processes, and is prone to product build up.
On the other hand, high porosity hair has many gaps and openings in the cuticle layer, allowing moisture to easily pass in and out. Highly porous hair typically dries quickly, is prone to frizz, and can tend towards feeling dry.
How to check my hair porosity
Other than analyzing basic characteristics such as how it feels to the touch and the length of time it takes to dry, as well as its ability to retain its moisture, there are a few DIY tests that can help you determine your hair porosity level. While these tests are not guaranteed to give an exact result, they can often help understand the general inclination of your hair.
Test #1: The Float Test
For this test, you’ll need a few strands of hair from your brush or comb (product-free) and a glass of water.
Drop the strands into the glass of water and let them sit for a few minutes.
After waiting, check the glass again. If the strands float after the time is up, you likely have low porosity hair. If the strands have sunk, the hair is likely to be high porosity.
If the hair floats somewhere in the middle of the glass, this might point towards medium porosity hair.
Test #2: The Spray Bottle Test
For this test, simply take a small section of your hair and spray it with some water from a spray bottle.
Watch closely to see how/if the water is absorbed into the hair strand. If the water beads up on the hair, it is low porosity. If the water absorbs quickly, the hair is high porosity
If you notice the water sitting on the hair for a couple minutes before absorbing in, the hair is medium porosity.
What does porosity level say about my hair care?
Low Porosity Hair is moisture resistant, meaning that it may be difficult to get moisture into the hair, but once you do, you don’t need to worry as much about your hair drying out.
Low porosity hair is often prone to product build up, so it is recommended that people with this porosity level opt for lighter products over rich ones to keep the hair from becoming weighed down.
Washing your hair with a sulfate free shampoo periodically can also prevent low porosity hair from getting weighed down and open up the hair cuticle to allow moisture to enter more easily.
Medium Porosity Hair has a looser but not quite open membrane layer, allowing for a moderate but steady flow of moisture in and out of the hair.
Medium porosity hair should cope well with styling, colouring, and chemical processes, though it is important to note that these processes can slowly increase the porosity of the hair over time.
Products that are balanced in moisture can help medium porosity hair remain healthy.
High Porosity Hair has many openings in the outer layer which allow moisture to pass easily in and out. High porosity hair has difficulty retaining its moisture
and tends to be more easily damaged as a result of UV exposure, heat styling and chemical processing. This can lead to frizz and tangling in humid weather, and extreme dryness in dry weather.
High Porosity Hair benefits from a lot of nourishment and moisture, so it is recommended to use products rich in moisture to help give the hair proper nourishment.
