Sunday, February 22, 2015

Glycerin and Humidity

Cindy asks a winter inspired question from frigid Wisconsin where humectants are making the winter of 2014-2015 even more frustrating. You need to know that here in the Midwestern U.S.A. (like Wisconsin), winter tends to be very cold and very dry. So even when we see the outdoor humidity is, say, 50%, if the temperature is 10°F (-12°C), the air is still extremely dry and the dewpoint - that temperature indicating how much water the air could hold if it was fully saturated - could be below 0°F. That is desert-dry air.

I zero in on glycerin because it can be a curly or wavy-haired person's dry-air nemesis. But I didn't leave many out, so read on. "Humectant" is a very broad category including salts, glycerin, plant gels like aloe vera or flax gel, algae extracts, hyaluronic acid, hydrolyzed proteins, sodium PCA, lactic acid, urea, witch hazel (without alcohol) and other ingredients that attract water. Not all humectants are "created" equal - different humectants behave differently in hair. I think when people complain about humectants, they are having the most trouble with simple humectants like: glycerin, propylene glycol, sorbitol.

Humectants attract water to themselves. Humectants like glycerin are great at grabbing water vapor out of the air. When you have a hair gel with glycerin in it, when there is ample water in the air (humidity) - the air is going to be hydrating the glycerin in the product, which is going to help your hair stay hydrated. Well-hydrated hair has more bounce and definition. A second benefit of glycerin in products (when there is ample water vapor in the air) is that glycerin keeps hold-providing ingredients that would otherwise create a brittle, candy-like finish from feeling brittle and candy-like. Glycerin (and sorbitol and propylene glycol) take water vapor from the air to hydrate the dry gel in your hair and keep it more flexible.

When there isn't enough water vapor in the air (low humidity and/or low dewpoints), the gel loses that benefit from the glycerin and the gel becomes more brittle, creates friction and that means hair that feels dry and crusty and looks dull.

Whether humectants actually dehydrate the hair - pull water from the hair is not well-studied. And it is an "it all depends" sort of question. It is based on a reasonable hypothesis; that if glycerin attracts water from the air, when the air is drier than your hair, water will move from your hair to the glycerin. For that matter, when the air is less humid than the inside of your hair - the water will tend to move from your hair to the air around it - glycerin or not. So does glycerin create a stronger "pull" (water gradient) than dry air alone? It probably does exert a stronger pull on the water in your hair than dry air alone. But not all humectants do that. Think of glycerin like brown sugar. In humid air, a bag or tin of brown sugar absorbs moisture and forms clumps. But it dries out quickly too and the clumps become hard as a result.

Don't discount the effect of that dehydrated gel sitting on your hair because 1) glycerin can't pull enough water out of your hair to keep a gel from getting brittle and 2) brittle gel creates friction - that means rough, tacky hair that frizzes when it contacts other hairs and objects and snags at cuticle edges. A crusty, dehydrated product in your hair is bad news for how your hair looks and feels.

Mitigating circumstances
If you used oil or leave-in conditioner under a glycerin-containing product, that layer of emollients would slow down water loss from hair. If there are other humectants that are not a ready to give up their water as glycerin in the same product, the effect might be reduced. Oils and conditioners act as "occlusives" - the layer of oil or leave-in conditioner is not water-soluble and that helps slow the movement of water in and out of hair.

Why glycerin, why must you be so fickle?
To get to the heart of why glycerin can be a problem ingredient for some people in some weather, one big issue is the size of the molecule. The smaller the molecule, the less water it can bind and hang on to when exposed to very dry air. Glycerin, sorbitol and propylene glycol are "sugar alcohols" - not alcohol like the kind used in hairspray. They are small molecules. There are not a lot of places on the molecule to bind water. Think of glycerin as a "simple sugar" as you would think of candy. Sure, glycerin and sorbitol and propylene glycol aggressively pull water to themselves, but they also lose it fairly easily. Emollients (oils and conditioners) can slow that down, but not stop it. So when the air is very dry - glycerin is a much less effective ingredient. Glycerin is a fair-weather friend. When the humidity is just right, glycerin can help your hair look and feel great. When the weather gets too dry, glycerin can't pull enough water to itself and it loses it's effectiveness. When the air is very humid and glycerin pulls lots and lots of water in - poof - your hair loses definition. 
Glycerin is a small molecule and not
very complex.

Formulation can be a problem
Often, a problem with a glycerin-containing product is that it uses only glycerin for a humectant and "flexibilizer" and does't use any emollients or film-forming humectants at all. Well-balanced products avoid this pitfall. Different humectants have different actions and a combination of different size and molecular weight humectants might be okay for a person who finds that just glycerin and no emollients or film-formers is a mess.

Is it just me?
There are people who live in climates that are dry year-round and use glycerin with no problems at all. And there are people who can only use glycerin when the humidity is "just right." There is no simple rule to determine how your hair will respond because it's not just a porosity issue. It's an issue of climate and weather, what other products you use in your hair, how sensitive your hair is to increased friction, how often you go outdoors. Trial and error. As usual. 

Is there a winter-proof (dry-weather-proof) humectant?
A great big molecule like the complex carbohydrates in flax seed gel or hydrolyzed proteins behave differently in hair than glycerin. These ingredients don't rely heavily on water vapor to work well. They don't have aggressive water-grabbing force. They're more subtle. There are many places to bind water in these molecules. Not only that, but they also form clear, flexible films over your hair. Water-hugging films that tend to slow water loss from the hair. If these large, moisture-retaining humectants which I call "film-forming humectants" are combined with oils or conditioning ingredients in a styling product, the humectants and oils and/or conditioning ingredients combine to actively attract and hold water and slow water loss, providing longer-lasting hydration and lubrication. The link in the previous sentence takes you to a list of film-forming humectants.
One of the many complex carbohydrates
in flax and other plant gels. It is a larger
molecule and more complex, capable of
forming water-hugging films.

Hair that cannot tolerate simple humectants like glycerin or propylene glycol may still do well with film-forming humectants in styling products. What we want from styling products is extremely personal. If you are looking for hold or definition, these are some styling products which may work:

AG Weightless Volumizer
AG Mousse Gel
AG Re:Coil
Aussie Real Volume Mousse
Aussie Instant Freeze Gel
Camille Rose Aloe Whipped Butter Gel
Curl Junkie Curl Queen
Curl Junkie Pattern Pusha
Biosilk Rock Hard Gelle
Darcy's Botanicals Curling Cream Gel
DevaCurl Set Up and Above
Goddess Curls Gel
Herbal Essences Totally Twisted Curl Scrunching Gel
Herbal Essences Set Me Up Gel
Herbal Essences Naked Volumizing Souffle
Jessicurl Confident Coils Styling Solution
LA Looks Nutra Curl Moisturizing Gel
Salon Care Aloe Vera Styling Gel
Pantene Pro-V Stylers Max Hold or Strong Hold Gel

For products that are based on film-forming humectants, including many natural and plant-based gels, go to  this page on this blog and scroll down to the list of products including film-forming humectants. Some contain glycerin - check the ingredient lists. Most are light to medium hold and can be topped with a gel with stronger hold, like Biosilk Rock Hard Gelee (from the above list) if necessary.

Why are plant-based, film-forming humectants less "fickle?" Stuff about plants.
Flax seed is an example. The gel comes from water contacting the seed. Seeds do this so that when they are in the soil and the soil is moist, the seed can attract water, form that gel which assures the seed will stay moist enough to sprout. If a seed gets wet, begins to sprout and then dries out, it dies. So this is a brilliant adaptive strategy to assure seeds sprout to create new plants and more seeds.

With aloe vera, that is a desert plant. It has thick, leathery leaves with spines on them to discourage animals from eating the juicy leaves and to prevent water loss. The gel in the inner leaf does not dry out quickly, a good strategy for a desert plant.







Saturday, February 7, 2015

Why Does White (or gray, light blonde, highlighted) Hair Turn Yellow: And what to do about it

This applies to white or gray, highlighted and blonde or light brown hair that may tend to become brassy or develop an unnatural color tint - yellow, red, orange or greenish.

White hair has no pigment. Although sometimes that's not entirely the case as a hair turns white. And sometimes there's a dark medulla to add color. The lighter your hair overall, the more likely discoloration from any source will show.


What causes yellowing of light-colored hair?
  • Water chemistry: Hardness or natural minerals, chemicals used for water treatment, seasonal water chemistry changes all impact whether or not your water discolors your hair. For example, if your water source comes from lakes and rivers, it varies greatly (within drinkable limits) with changing seasons and the treatment needed to make the water safe to drink. Some water is high in iron which can give hair an orange, red or yellow cast. Other things in water (metals) can cause green or brown discoloration. Alkaline water can be also problematic (hard water that feels slippery). It's not just minerals that vary, it's nitrates and nitrites, the amount of chlorination required, use of chlorine vs. chloramines for disinfection and whatever your water picks up from pipes on the way to you. 
  • Hair products. Some oils and emollients, preservatives, and colorings can leave a yellowish cast on hair.
  • Scalp oils. Sometimes you own sebum can give your hair a yellowish cast. And your own sebum can vary with seasons - sweat, heat or cold, activity level, microbial activity on your scalp. Natural sebum is a good thing. Don't panic over one. But if you have oily scalp and you are not forcing it to produce lots of oil by over-washing it, wash it regularly - just don't dry it out. If you wear a hat often - wash the hat regularly or put in a hat band or liner that you can remove and wash.
  • Smoke, pollution. Your hair can pick up these things. Especially close-up smoke like that from smoking cigarettes.
  • Swimming pools and ocean water. Minerals in pool fungicides can cause a greenish or yellow tint, chlorine can increase hair porosity. Salt water dehydrates hair and causes porosity-increasing friction.
  • Sunlight: UV light tends to make hair become more porous and it may also induce yellowing in some hair.
  • Chemical processes: Perms, relaxing can make hair more porous so it is more easily discolored.
  • High-heat styling. Heat from hair dryers on the "high" setting or much higher heat from curling irons or straightening irons tends to make hair more porous so it is more easily discolored. 

What to do?

1) Purple shampoos or conditioners - usually made for grey, blonde or silver hair. Purple is meant to cancel out the yellow shade - to deposit a tiny bit of purple to trick your eyes into not seeing the yellow. A purple additive such as "Ardell Red-Gold corrector" is a commercial product which can be added to shampoo, hair gel or leave-in conditioner so that it is a light shade of purple if you prefer not to use an unfamiliar product.

2) Bluing. Mix a few drops of liquid laundry bluing into shampoo or conditioner - or just a little into a leave-in conditioner or hair gel so it is "sky blue." This color of blue is very effective at canceling out yellow shades in white hair and also in toning down brassiness. It especially enhances cool shades of brunette and dark brown hair and can give blonde and light brown hair an ash (cool) tone. If purple doesn't help - blue (bluing) may work better.

1 and 2: a) Use food coloring instead. You can use a few drops of blue food coloring in shampoo or conditioner, or blue + red to create purple. If this mixture, or a purple shampoo almost works, but you still have some reddish shade appearing, add the same number of drops of green food coloring to the mixture (example: 1-2 drops each of blue, red, and green). Have a mirror handy. If you over-did the color additives, wash your hair a second time.

3) If minerals or metals (copper, iron for example) in water are discoloring your hair, try a distilled water wash. Warm some distilled water and use it for your entire wash and rinse. This can help diagnose whether water chemistry is a problem for your hair. If you notice a benefit from doing this, you might try combining it with one of the suggestions from #4 or #5 below to remove minerals from the hair, or with a purple shampoo or a bluing-added product from #1 or #2.

4) Hard water shampoos and treatments (commercial). Ion Hard Water shampoo, Ion Hard water treatment, Malibu Wellness Hard Water Weekly Demineralizer or Malibu Wellness C Blondes Weekly Brightener. These treatments can remove hard water minerals (calcium, magnesium) and other problem minerals from your hair. But if you have more white hairs than colored hairs or you have very light blonde hair or light highlights, you must do a test section first to be sure you will not get discoloration from the treatment.  These treatments combine mineral chelators such as EDTA or citric acid with mineral dissolvers and detergents to remove product build-up. Hard water can exacerbate product build-up.

5) Lemon juice treatment (Do It Yourself). This is shampoo-free. It may help remove mineral deposits and it may brighten blonde and light brown shades. Mix equal parts lemon juice (strain out any pieces of pulp) and distilled water. Apply this to your hair (put it in a squeeze-top bottle for easier application or mix with some xanthan gum to make a gel). Work it in well and cover your hair with a shower cap, treatment cap or wrap your hair in plastic. Leave this in your hair with some heat for 3-5 minutes, then rinse well and follow with cleanser/shampoo and conditioner.
The pH of this treatment is very low, so you may want to do a test-strand first to assure it is not too drying for your hair. The combination of citric and ascorbic acids help dissolve and trap (chelate) minerals and remove them from your hair. 

You can make mock lemon juice with 1.5% each citric acid and ascorbic acid in distilled water. This will also have a very low pH and need to be used on a test-strand to make sure it does not dry your hair.

6) If you notice yellowing after adding a new product, the product may be the problem. Discontinue use of the product for a while. If it is more than one product causing the problem, scan the ingredients of the offending products for ingredients they have in common. Those ingredients may be potential offenders. Oils, some preservatives, herbal ingredients and colorings can discolor hair, for example.

7) If you began using oils in your hair, or if you have been sweating more than usual - you may need to shampoo your hair more thoroughly. You may find that some plant oils cause yellowing and others don't. Or some parts of your hair may be more inclined to yellow than others.

8) Treat any scalp disease you may have (seborrheic dermatitis, for example) so the oils on your scalp have the right composition and are not over-produced. You may want to avoid tar shampoos (unless that is the only thing that works) because they can cause discoloration.

9) Manage porosity in your hair by using conditioners, protein as your hair tolerates it, handle your hair gently (don't brush vigorously, don't rub and scrub it with a towel - just blot and squeeze dry), use oil pre-wash treatments to prevent "waterlogging." See this post for more about managing porosity.

10) Wear a hat, scarf of "UV buff" in the sun or use a UV protectant in hair products such as Octylmethoxycinnamate, Cinnamidopropyltrimonium chloride, Benzophenone-4, Quaternium-95 and Propanediol, or Polysilicone-15 

11) For swimmers, use one of the mineral-removing treatments from #4 and #6 occasionally. If your pool allows, apply a little coconut oil or conditioner to your dry hair and wear a swim cap. The oil or conditioner protects the hair from pool water and the swim cap doesn't allow new water to constantly flow past and through your hair.

12) Other commercial products: 
  • Manic Panic "Virgin Snow" is a conditioning "white hair toner" (it's purple in the bottle) with no peroxide that is left on the hair for 15-30 minutes to correct discoloration. 
  • L'Oreal Colorist Secrets 'Brass Banisher" is a product that does contain peroxide for removing unwanted brassiness (red and yellow colors). If all else fails...

Sunday, February 1, 2015

Hair Porosity: The Float Test Part Two

It's time to examine the float test for hair porosity more fully. I began looking into how the float test could give you an inaccurate result in the previous post. Elsewhere on this blog I have mentioned that this test is not very accurate. This post will show you why.
© Science-y Hair Blog 2015
The really, really short story:
If your hair floats: It probably tells you nothing about the porosity of your hair.
If your hair sinks: It probably tells you nothing about the porosity of your hair.
The "float test" is irreconcilably flawed thanks to having too many variables working at the same time, including how you do the test.

The idea behind the float test follows this line of thinking: If hair is porous, it takes on more water than if it is not porous. Therefore, porous hair might sink because it takes on water and becomes heavy. That is - the weight of the water the hair is absorbing overwhelms the power of surface tension (between water molecules) that keeps the hair suspended on top of the water.

And in a sense this is not wrong but it is incomplete. But there are too many other variables in play to make this an accurate assessment of how porous your hair is by simply grabbing some hair and dropping it in a glass. Your experiment needs to be designed with far more care than you might think to get anything close to an accurate result. Given time and enough dunking - all hair will sink in water and stay sunk.© Science-y Hair Blog 2015

I used some hairs which are low porosity, porous, kinking and porous and mixed porosity (lower near the roots, porous at the ends). I tested the hairs when clean (no products), with conditioner added, with coconut oil added and with hair gel added (homemade flaxseed gel) because these additions can change the floating behavior of hair.© Science-y Hair Blog 2015

In most cases I put some hair on the water's surface and also dunked another of the same hair because some people dunk their hair (push it under the water) for the float test and it tends to give a different result, at least at first. Captions are below each chart. Click photos that follow to enlarge.© Science-y Hair Blog 2015


Time
Untreated
Oil (All dunked)
Conditioner
Hair gel
Start
Floating, Dunked: Sinking
Sinks
Floating, Dunked: Sinking
Floating, Dunked: Sinking
5 minutes
Floating, Dunked: Sinking
Floating
No change
Floating, Dunked: Partly floating
10 minutes
Floating, Dunked: Sinking
Floating
Nearly all floating, dunked and un-dunked
Partly floating, dunked and un-dunked
Porous, coily/curly (Type 4) hair which has been lightened (highlighted). When untreated, it did partly sink over time. But at least half of the hair was on the surface. With oil, it initially sank when dunked (all hairs were dunked in this case), but then floated as the coconut oil repelled water. With conditioner, the un-dunked hair floated until the end of the test when it was partly sinking but the dunked hair sank initially, then floated as the weight and specific gravity of the hair vs. water and the waterproofing of conditioner got the better of it. Hair gel in this case was similar to un-treated hair - though hair gel can make hair more water-attracting.

Time
Untreated
Oil
Conditioner
Hair gel
Start
Floating
Floating, Dunked: Floating
Floating, Dunked: Sinking
Floating, Dunked: Sinking
5 minutes
Floating
Floating, Dunked: Floating
Partly floating, dunked and un-dunked
Partly floating, dunked and un-dunked
10 minutes
Floating
Same as at 5 minutes.
Same as at 5 minutes.
Same as at 5 minutes

Mixed porosity hair (lower porosity at roots, porous at ends), loose curls with kinking. The untreated hairs all floated (none were dunked). The oiled hairs also floated. With conditioner, the wet-ability of the conditioner encouraged sinking, whether the hair was dunked or not. With hair gel, the wet-ability of the hair gel encouraged sinking.

Time
Untreated
Oil
Conditioner
Hair gel
Start
Floating, Dunked: Partly sinking
Floating, Dunked: Floating
Floating, Dunked: sinking
Floating, Dunked: sinking
5 minutes
Floating, Dunked: Partly sinking
Floating, Dunked: Floating
Partly floating, dunked and un-dunked
Floating, Dunked: Partly floating
10 minutes
Floating, Dunked: Partly sinking
Floating, Dunked: Floating
Floating, Dunked: Partly floating
Floating, Dunked: Partly floating

Low Porosity, coily (Type 4), kinking hair. This hair floated as expected when untreated and simply placed on top of the water - but it seems the shape of the hair pulled it down when dunked. It floated when oiled both dunked and un-dunked. Conditioner's wet-ability encouraged some sinking with time, as did hair gel.

Time
Untreated
Oil (All dunked)
Conditioner
Hair gel
Start
Floating, Dunked: Partly floating
Floating
Floating, Dunked: sinking
Floating, Dunked: sinking
5 minutes
Same as at start
Floating
Floating, Dunked: partly floating
Floating, Dunked: partly floating
10 minutes
Same as at 5 minutes
Floating
Floating, Dunked: mostly sinking
Floating, Dunked: partly floating

Porous, wavy hair, which has been lightened (highlighted).
The porosity of this hair encourages sinking when the hair was dunked. The hairs floated when oiled but conditioner's and hair gel's wet-ability encouraged sinking in the dunked hairs.

Comments:
Do you see any trends? © Science-y Hair Blog 2015
  • Porous hair does indeed tend to sink somewhat reliably: 1) if the hair is clean - no products 2) over time, 3) if the hair is dunked under water first.
  • Conditioner and hair gel on hair tend to encourage hair to sink if it has been dunked under water first - but it may float after a little while. 
  • The curl of hair or lack of curl or for that matter if you have hairs touching other hairs, may change the result, especially if you dunk hairs.
  • Oiled hair tends to float - especially coconut oil.
  • Dunked hairs vs. hair placed on the surface may produce a different result. And that result may change if you leave the hair for a few minutes. As you can see from the charts - whether or not a hair that sinks at first may float later on is not predictable, so I don't want to encourage you to try to predict a result based on whether it sinks and then floats. That's not accuracy.
Can you get an accurate result with the float test?
I am inclined to say no. If your hair is very porous like the porous hairs I selected and if it is very clean, then you might get a "porous" result. But if there is oil or conditioner or hair gel on your hair, or if it is just a little bit porous - you will not get an accurate result.

If your clean hair is low porosity at the roots and normal or porous near the ends, your hair will probably float, or sink partly - but if it does sink - is that because you dunked it, because there was some conditioner residue, because it came into contact with the side of the container? What other forces are acting on the hair? How porous is it really? More information is needed!
Untreated, low porosity hair floating after 10 minutes. Talk
about water surface tension!

So how do you test porosity? This post goes into depth. In general, lower porosity hair doesn't have damage. It also doesn't dehydrate easily - and that means it doesn't get dry on the inside and brittle. Lower porosity hair doesn't soak up a lot of oil and conditioner. But sometimes hair won't "soak up" those things because you've used henna, or because your hair is coarse (wide) and not very flexible (lots of inner support). Lower porosity hair doesn't tend to "take" hair dye or permanent waves or chemical relaxing easily. Normal porosity takes hair dye normally and porous hair takes hair dye very quickly. If your hair is generally very tolerant of just about everything, it's probably low to normal porosity. Most hair is more porous on the ends than near the roots. If your hair always seems to dry out easily and get brittle and break, it's more likely to be porous. If your hair is dyed or highlighted, it's more likely to be porous (but some hair will resist becoming porous with dye and bleach). If you spend a lot of time in the sun or swimming, your hair is probably porous - though it may or may not be as "dry" as you might expect porous hair to be.

Powers of observation
At top left, lower porosity curly hair and in bottom, center,
porous, wavy hair with conditioner applied. Blue
arrows indicate where hairs has sunk beneath the surface.
Bubbles tend to appear when products are applied.
Of all the tools and products for hair, your eyes, hands, ears and mind are the most important. If oil and conditioner just sit on top of your hair, if you've never dyed it nor handled it especially roughly, it's probably lower or normal porosity. If your hair doesn't soak up loads of oil and conditioner, but can tolerate whatever a normal amount is for your hair length and thickness and curl pattern without getting greasy immediately and sometimes gets a little dry or lighter-colored, frizzy or flyaway or the ends start to look light (or invisible) - you're probably lower porosity at the roots, normal in the middle and more porous on the ends. If your hair soaks up lots of oil and conditioner and never seems greasy or weighed down and tends to be dry and brittle and always breaking - higher porosity.

You decide how to treat your hair based on your baseline observations and how it responds to what you do to it. This post has recommendations for keeping lower porosity hair or hair that is difficult to moisturize feeling good. This post is about hair that is low/normal/porous and porous hair can use protein (if it's not coarse) and oil pre-wash treatments and deep conditioning to your heart's content. If you use a heavy-handed oil application and see a glimmer of improvement, but you needed to wash your hair 3 times to de-grease, don't swear off oils. Just use less. Maybe a lot less. Observe, make a plan, experiment, observe again, adjust as needed. © Science-y Hair Blog 2015
Mixed porosity, curly and kinking hair, untreated. Still floating
after 10 minutes.
A porous hair (top, lighter brown, coiled up) and low porosity hair
(bottom, more elongated) with hair gel applied. Both are partly
sinking due to the product and having been dunked under the
water. Bubbles tend to form when products have been applied.

Sunday, December 28, 2014

Testing the "Float Test" for Hair Porosity, Part One

Porosity is tricky to define because of these three things:

1) Porosity is a physical condition that belongs to an individual hair - or a portion of a hair. It is the amount of surface area with porosities - gaps and holes through which water and other things can move.

2) Porosity is a behavior or your individual hairs and your hair as a whole - how quickly does water move through any porosities present.

3) We want to use porosity to determine what to do to our hair - but all the things we do can modify our hair's porosity-behavior or even mask actual porosity. For example, sun-damaged and therefore porous hair may feel different than bleach-damaged and therefore porous hair. Or hair which is easily weighed down or low-density (thin hair) may or may not be able tolerate lots of conditioner and heavy oil applications that we usually think porous hair needs. Different porous hair has different needs.

Why does porosity-behavior matter? Let's say you use a henna or cassia treatment on porous hair and it suddenly seems to be water-repellant. It doesn't seem to get wet and dries very quickly. That is a behavior of very non-porous hair. The same thing can occasionally happen with protein treatments or oil treatments, especially with coconut oil or butters.

Has that hennaed, cassia-ed or oiled hair truly become less porous? Yes and no. The porosities that were there before still are there. But the movement of water through those porosities has been delayed by the henna or cassia residue. The hair's behavior is less porous, but the hair still has porosities - it just takes a lot longer for water to move through them. With coconut oil and hair-penetrating oils, the oil repels the water, causing non-porous behavior in normal porosity to porous hair.

Experimental design
When we want to set up a test, one of the first things we have to consider is this: are there any ways this test can be biased? In other words - does anything in our hair's environment change the results of this test?

To do this, I'm taking hairs from one person. These hairs are low porosity on the top 1/3, normal porosity for most of the length and more porous towards the ends. No hair color, no henna, no cassia.

We have 4 "treatment groups."
- Hair which has nothing added (washed and dried with no conditioner or styling product)
- Hair which has coconut oil applied
- Hair which has leave-in conditioner applied
- Hair which has a little oil and flaxseed styling gel.

The water temperature is lukewarm - not warm enough to liquefy oils and not cold. I used a glass dish of water with a large surface area for this - which is actually also important to the results of the test because the hairs did not contact the sides which might override the surface tension of the water. More on that in another post.

I treated the hairs and placed them lightly on the water surface. Every single one floated immediately.
Click to enlarge! Black arrows point to hairs floating on the surface. These are all lighter colored hairs and even with the contrasting color background, the camera had a difficult time "seeing" the hairs on the water. 

I left the hairs for 2 minutes. Still floating. And still floating a minute later. I'm impatient, so I dunked them quickly.

After dunking: The hair with conditioner began to sink. About 1/3 of the hair's length ultimately sank. The rest remained on the surface of the water. Until I gave up after about 10 minutes.
Click to enlarge! Black arrows point to the place where the hair with conditioner on it is submerged (to the right of the arrows) vs. floating on the surface (to the left of the arrows).

Simple conclusion for Part One: Lots of leave-in conditioner or conditioner-enriched styling products can encourage hair to sink that would normally float.

Now we are already asking ourselves - is this a good test if we have to control conditions carefully or we get a biased result?  In science, that is okay. For example: You can't get accurate results from reactions you do in dirty test tubes. Those things that go into your experiment usually need to be controlled in one way or another. But if you just wanted an accurate result from your hair and you have leave-in conditioner or conditioning hair products in it - it's more likely to sink. Though it may not!

Conditioner is a 'wetting agent" so we could have predicted this result. If you need to get your hair wet in a hurry - put conditioner on it first. It will get wet more quickly. Did the conditioner act as a wetting agent here? Probably. It added weight - but not that much weight and the oiled hair also had additional weight and it did not sink.

Did the oil repel water and keep the hair floating? Apparently not. Because the hair which was washed and the hair with a little oil and hair gel also floated right along with the oiled hair.

Should I have left the hairs for 30 minutes? Overnight? I don't think that's going to improve the test. Anybody's hair will get waterlogged after that long in water.

Next time: Hairs of different widths, curl patterns and porosities. I'll be using darker-colored hairs and daylight - the pictures will be much better.




Sunday, December 7, 2014

Laundry Static-Control Tip

Upcoming post news:  I've been a busy blogger - but not busy blogging.  Currently I'm working on a post in which I'll examine (and photograph) the at-home test for hair porosity called the "strand float test." Look for that in the coming week.



Here's a handy laundry tip for cutting static in laundry coming out of the dryer without using fabric softener. Fabric softener tends to make towels less absorbent and coats laundry. It also tends to be heavily fragranced (unless you buy fragrance-free). In winter I like to dry laundry on a rack indoors like in this post. But some things won't fit, like sheets.

So that's where I use aluminum foil. Pull off a large-ish piece of aluminum foil - a little larger than a letter-size sheet of paper. Crumple it up - try to crumple the edges on the inside to make the ball last longer and avoid sharp edges. Make 2 or 3 of these and toss them in the dryer with your laundry. You won't get shocked when you handle the laundry, it won't crackle and pop. And you won't walk around with a sock or a dryer sheet wriggling out of your pant-leg over the course of the day.

These will last for weeks. In some municipalities, you can recycle aluminum foil when you're done. But others will not accept foil for recycling, so be sure to check before you try to recycle it.

It works like this - in your laundry, the clothes build up electric charges from the hot, dry air and tumbling around, colliding with each other. Aluminum foil is a metal and it will conduct electricity - so the charges in the laundry flow through the foil, essentially neutralizing the charge on the laundry.

Monday, October 6, 2014

Huh? Air Drying is Bad for Hair?

Don't panic, air-drying is not going on your list of things you need to feel guilty about. Won't you join me in getting all "critical thinking-y" about this subject?

This post is in response to a blog reader's question about a recent study which reported that air-dried hair acquires some internal damage during drying whereas blow-dried hair accumulates more external damage. The study was published in the Annals of Dermatology, November, 2011: Hair Shaft Damage from Heat and Drying Time of Hair Dryer, Lee et. al. 

If you thought air-drying was best for hair - this catches you off guard, to be sure. But while I did a double-take when I saw that eye-grabbing factoid in what I think of as "hair social media" - after reading the article I think this information was taken out of proper context. In other words, it makes a great headline, but there is not enough information provided to support the idea that air drying is bad. Please, read on.

Some things to consider before digging in:
A) I don't think the authors made a solid case against air-drying, nor did they set out to do that. They are simply reporting an unexpected result, not condemning air-drying of hair. Human hair is made to air-dry. Maybe not to be washed frequently - but air-drying is part of our natural history. 
B) Blow-drying does a fair amount of surface damage; cracking the cuticles of the hair thanks to the rapid change in temperature and moisture. Cracked cuticles are rough and stick up. When cuticles stick up, they break off easily. The result of too much blow drying is dull, dry, rough, porous hair. 
C) Air-drying causes a lot less surface damage so your hair is not so rough or dull. That's why it is better for hair's feel and appearance, long-term.
D) The internal damage recorded in this study of the air-dried hair is of unknown consequence. Human hair has been air-dried for generations upon generations. Are we going to condemn it based on one study that found an interesting result but drew no conclusions based on that result
E) Researchers were not able to control how the hair was dried before it was used as a sample. This is an uncontrolled variable. We don't how the history of this hair sample/these hair samples may have influenced the outcome. Picky, picky! 
F) What is unclear to me is - did they use just one hair sample? How many heads of hair were represented here? The same hair sample for all 5 treatments? It looks like each treatment was a 2 gram sample of hair. This is not enough information for me. I would call a test based on one sample a "case study," not an experimental result.

The actual test was to repeat these treatments once per day, 30 times total in hair which is probably straight or wavy hair (from De Meo Brothers, Inc.), so there might be slight kinking but probably not much. The hair was washed in a shampoo containing 10% sodium lauryl sulfate (the absolute concentration of detergent as a raw ingredient is not stated, but this is actually on the low side for a shampoo), then excess water was "shaken" off and the hair was dried using the following treatments: 

1) Hair with no treatment - no washing or drying (control)
2) Air-dry hair at room temperature of 20°C (68°F)
3) Hair dryer, "low" temperature for 60 seconds, 47°C (116° F) at 15 cm (6 inches) away from hair
4) Hair dryer " medium-high" temperature for 30 seconds, 61°C  (142°F) at 10 cm (4 inches) away from hair
5) Hair dryer "high" temperature for 15 seconds, 90°C (203°F) at 5 cm (2 inches) away from hair.

Note: No conditioner, no oils, no heat protectant, no styling products. This is only meant to test the "naked" hairs.

So what did they find?
-With increasing heat, there is more surface/cuticle damage, despite shorter exposure to heat as they turned the heat up.
-With air drying (which took 2 hours) there was bulging in the portion of the hair beneath the cuticles as a result of the time the hair spent wet. This is the piece of information that has been seized upon by women's magazines and hair social media. I remind you - this may have occurred in a single hair sample. This does not necessarily mean everybody's hair acts like this. We simply do not know. The authors did not provide adequate information about their hair samples and the editors apparently missed that omission.

Why did they get this result in air-dried hair?
When normal porosity and porous hair is wetted, it absorbs water. As it absorbs water, it swells - but it is the inner portion which includes the cell membrane complex which does the swelling. Shampoos increase swelling unless they contain very mild detergents or very dilute detergents. The cuticle layer cannot swell or increase in girth. So we have a problem - a swelling interior and a non-swelling exterior!  That's stress - kind of like frozen water inside a pipe. More about that in this blog post

Is this a problem for hair? We don't know for certain. Too much swelling in hair probably makes hair a little weaker in structure. If you spend a day in the rain with your hair wet, it becomes more troublesome - tangly, behaving differently. If you spend a lot of time swimming - even in fresh water - your hair will weaken. That swelling of hair pushes cuticles up so they are easily broken off and water has access to the cuticle layer and beneath and can leach away anything water-soluble and probably even some oils. These actions increase porosity.

What would be a convincing result? I think a similar test would need to be done on hair from multiple donors, including a variety of hair widths (fine/medium, coarse, very coarse), including curly and kinking and coily (type 4) hair. A more convincing sample size (to me) would be about 3-5 of each of these. A result you can replicate in a variety of specimens is a result you can really get behind! If most hairs showed the same effect from air drying but not from blow-drying, then we can make some real conclusions. But we still wouldn't know the actual implications of the so-called damage. Maybe that's not structural damage at all. Maybe it's normal. It's not as though hair is meant to last forever.

What's good about air drying?
Air drying causes less cuticle damage (porosity) and cosmetic damage than heat-drying, that's a good thing. It makes some people's hair frizz less and that's a good thing too. Air drying doesn't use electricity - so it keeps your carbon footprint smaller and that's a good thing. You can do lots of activities while your hair air-dries - you're not tied to a hair dryer and that's a good thing. Some hair that isn't naturally straight (most of us) looks better when air-dried.

How to Air Dry Without feeling Like We're Slowly Destroying Our Hair? (I enjoy a little hyperbole). One of these may fit your lifestyle and hair styling requirements.

1) Use hair-penetrating oil treatments for 6-12 hours, especially on the length of your hair. Use coconut oil or sunflower oil, or olive or castor oil. These will help normal porosity and porous hair behave as though it is less-porous. It will swell less in water and you can avoid this problem. This really works. You don't have to soak your hair with oil either. See this post for details. You may even find you have a faster drying time with these treatments over time. 
2) Squeeze water out of your hair (styled or not) before air-drying. It will dry more quickly. Use an old t-shirt, a pillowcase or a cotton dish towel (tea towel/flour sack towel) to avoid creating frizz.
3) Limit your time under the water. I.e. wash your hair last. The less time your hair spends under water, the less saturated it will be. Yes, sometimes we need to get our hair all wet and juicy to be hydrated. But too wet for too long = waterlogged.
4) Wash or wet your hair less often. Works for some hair and lifestyles, not others.
5) Go as light on the styling products as possible. Lots of leave-in conditioner and lots of hair gel causes longer drying times.
6) All styling products make your hair take forever to dry? Try a styling foam or mousse - something that doesn't increase drying time, move around while your hair dries, step out in the breeze.
7) If your haircut is all-one-length, thick hair that takes forever to dry, getting some well-placed layers will shorten your drying time.


Best of both worlds?
You can slice your drying time in third or half by using a hair drier with a diffuser (to disperse the heat) either at the beginning of the drying time or at the end - whichever gives you a better result - for a short while. Maybe 3 minutes, maybe 8 minutes. Just to get the air moving and evaporate some water from your hair.

How long is too long to spend with wet hair? Nobody knows for sure. If your hair dries in 1 to 3 hours, you're probably okay. If your hair takes all day to dry, it may be getting stressed from all that time spent in a wet state. For example, if I am caught in the rain and my hair is wet all day, it becomes more tangly than usual and feels mushy or spongy when I wet it again - a sign that it needs a protein treatment for strength. And it will also need an oil treatment before it starts to feel it's normal self. To me, this is an indication that my hair was weakened by having been wet for 6 to 8 hours. I don't experience that result from my short showers and usual 1.5 to 2 hour drying time.
Your experience may be different from mine - watch your hair's behavior under different conditions and let that be your guide. If you use deep conditioning treatments in which your hair is wet all night, or you let your hair be wet overnight - that's probably too long to have wet hair and you may be weakening it.

Bottom line: Air drying is better for the surface of your hair (porosity) than heat-drying with a blow dryer. There isn't any clear evidence that air drying is bad for your hair at all. But spending too long with your hair in a wet state is stressful, including very long dry-times.