Hygral Fatigue: A Hair Care Issue?

Is hygral fatique a common hair care issue? Not for most people from what I have read and know. It is not an issue cosmetic chemists write about as such. I searched and came up with nothing on that as a topic, nor was it a specific issue when I worked in the cosmetic industry. Hygral fatigue is said to result from the constant swelling and de-swelling of hair that has too much water in it.

Too much water having access to hair can remove hair dye molecules, causing fading and tangling hair damage. A simple remedy for that can be switching to a gentle shampoo for colour-treated hair, which contains extra conditioning ingredients.

Hair can swell and become "poofy" when there is too much water vapour in it but that is not the same thing, going by the research study on hygral fatigue. The remedy would be the same though, helping to keep too much water in either form from accessing your hair, while your hair is lubricated, to help stop abrasion and keep needed water in your hair from evaporating. Excess water or moisture evaporates.

You can certainly find hygral fatigue written about on the Internet, in blogs like I am doing and have done and articles, all referring to that same study, that no doubt has increased coconut oil sales and more recently, pre-wash treatments. If you swim frequently, there are other considerations, like chlorine and salt water hair damage that can allow more water to enter your hair. Salt water swimming pools do contain chlorine. The links still work in that post.

Hygral fatique appears to have been named as a condition by the researchers in the study and has become a buzzword used by specific marketers, or others referring to the research. If it is a specific hair issue, it would be discussed by cosmetic chemists as a challenge to help overcome and it would be used in advertising and marketing for hair products generally, as a term for the promotion of a product to deal with or help prevent, like dry or porous hair.


Hair samples used and how they are prepared for testing in scientific research impact results, as do all samples and methods used for scientific investigation. In that 2001 research study, according to Page 170, colour added by me,
"The hair sample was black Indian hair obtained from individuals who did not use coconut or mineral oils as hair dressing". 

The control samples were cleaned prior to testing, according to the text provided. Therefore to me, the untreated control samples that were submerged in water for one hour were more vulnerable to swelling because of the cleaning, which also would have removed natural oil from within them.

From Page 171, colour added by me
"The drops of oil were placed on hair swatches and were spread onto the hair fibers with a fine-tooth comb. The samples were stored overnight, and then the oil remaining on the surface was washed with a 20% solution of sodium laureth sulfate and the swatches were rinsed thoroughly, air-dried, and stored at room temperature. Control samples were treated in a similar way, except for treatment with the oils." 

There is room for interpretation of the text on hair sample preparation. In other studies funded by the same company referred to in this blog, in 1999, Pages 328 and 329 and 2003, Page 178, the hair samples used were also pre-cleaned prior to preparation for testing. However, I go by what is actually written in each study. I would need to contact the researchers or company to verify and clarify hair sample preparation in this case.

It gets even more complicated on Page 178 of the 2001 study, colour added by me.
"Characteristic positive ions of mineral-oil-treated hair. The positive spectra obtained from the surface of the cross sections of hair fibers treated with mineral oil are similar to the spectra of the untreated hair (Figure 9). No mineral oil was detected in the treated hair. However, coconut oil and polydimethylsiloxane peaks were observed in the high-mass range, similar to observations made for the untreated hair fiber. This indicates that these hair fibers had been exposed to coconut oil as well as silicones and surfactant."


From this research abstract, dated 2009, colour added by me,
"Hair is one of the most difficult proteins to digest or solubilize. Among the most common dissolving procedures for hair are acidic, alkaline, and enzymatic hydrolysis." 

See also this information
"The keratin found in hair is called "hard" keratin. This type of keratin does not dissolve in water and is quite resilient. .... Hydrogen bonds account for one-third of the hair's strength. The hydrogen bond is a weak physical side bond that is easily broken by water or heat. Hydrogen bonds can be reformed by drying or cooling the hair." 

Information on the elasticity of hair can be found in the book Chemical and Physical Behavior of Human Hair, 2012 by cosmetic chemist Clarence R. Robbins, in a searchable preview here. The swelling of hair can cause damage. Hygral fatigue though is not mentioned.


Effectively neutralizing chlorine immediately after swimming can prevent chlorine from crystallizing in your hair and causing damage once your hair has dried. Removing sea water salt and other minerals helps prevent hair damage too. Saturating your hair with water prior to swimming may help as well. If your hair already has oil or silicone on it from your usual hair care routine, too much water should not be absorbed by doing that.

Damaged hair needs extra protection to not absorb too much water at any time. There are various products that can help. Added oil is one of them but using a lot of oil or other products whether your hair is damaged or not is not necessary.

The shampoo I use contains one silicone and catnip contains some oil. I use mineral oil baby oil in between catnip use and occasionally, a very small drop or so of it in addition to catnip for extra polish. My hair is not dry and it has not become frizzy, even in conditions of high or low humidity in a long time. It used to become slightly frizzy very rarely, a good while back now.

That was most likely because I used too much shampoo. The natural oil in your hair is a defense against too much water entering your hair as well, to a degree. Overusing any product that can remove or emulsify oil reduces that protection.

Hair Protein Loss And Coconut Oil, Hygral Fatigue And Mineral Oil

This is often referred to as the "definitive study"on coconut oil and hair protein loss. However, it is not said in the study, as is often stated on the Internet, that the observed protein loss coconut oil can prevent is from inside the hair shaft. An explanation is given as to why in detail. The hair tested was washed with sodium laureth sulfate only, not shampoo, after initially being cleaned, See Pages 178, 179 and 180. Most commercial shampoos today contain one or more quaternary ammonium compounds, e.g. polyquaternium 10, which also acts as a combing aid.

This text below is quoted directly from the study, on Pages 185 and 186, colour added by me. See Page 180, which names the protein loss testing method used.

"RESULTS AND DISCUSSION
PROTEIN LOSS

The process of cuticle chipping that results from abrasion of hair against objects such as grooming devices or even other hair is a major factor in hair damage. The proteins that constitute the cuticle cells are lost during wet combing. It is well known that wet combing is accompanied by the breaking of the surface cuticle cell because of its brittleness. Histologically, the major component of the cuticle cell consists of the exocuticle and the endocuticle. The exocuticle, being highly cross-linked is not swollen by water. The endocuticle and the cell membrane complex, on the other hand, are less cross-linked and are more vulnerable to swelling damage. This leads to the lifting of the surface cuticle via bending. Such cuticle cells can be broken in the process of combing or teasing. The protein loss observed in these measurements results mostly from the cuticular region. Because of the short time involved in the combing and brief immersion of the combed tress in water, it is unlikely that proteins from the bulk of the fiber are involved in this measurement."

In the first study undertaken by the same company, a commercial shampoo used (shampoo 1), showed almost the same results on curly and straight hair as the use of coconut oil as a "prewash treatment", See the graphs on Page 334. The text on the left underneath the graph "Figure 6.", should have said without coconut oil. See this blog post on pre-wash treatments.


After rereading their 2001 study on coconut oil hair penetration, hygral fatique and mineral oil, it supports what I wrote in the post below and in this one, plus research in this blog post and the 2012 COSSMA reference here.

The researchers submerged untreated and oil-treated hair in water for one hour, See Page 182 and quoted from Pages 183 and 184, colour added by me.

"While both oil-treated categories show a significant decrease in swelling, it is slightly greater for the coconut-oil-treated fibers than the mineral-oil treated specimens. In coconut-and mineral-oil-treated specimens, swelling is reduced by 48% and 33%, respectively. This strongly suggests that the fiber is protected from damage by hygral fatigue (swelling and de-swelling).

It should be emphasized that the reduction in moisturization of the fiber does not make the fiber rigid because of the plasticizating action of the absorbed coconut oil. ...

Mineral oil also shows lower levels of swelling compared to the untreated fiber, suggesting that it may have penetrated into the cuticular regions, thereby preventing further penetration of water into the hair shaft during the swelling experiment.

Significant reduction in swelling suggests that this will prevent swelling and deswelling (hygral fatigue) of the fiber. Hygral fatigue can lead to cuticular damage as well as damage to the cortex, which can, in turn, affect the mechanical properties."

In other words, mineral oil can also reduce too much water from entering the hair shaft and it can penetrate deeper than just the surface of the hair. Coconut oil in experiments on hair without barrier coatings does not make hair stiff when it penetrates hair, See Pages 170 and 171 for information on the hair used and how it was prepared just before the testing for oil penetration (washed with sodium laureth sulfate). 

From results reported on oil shampoo and my own results with it, lauric acid penetration and penetration to a lesser degree by the other fatty acids in coconut oil did not result in stiff or "crunchy" (very dry) hair either, even when coconut oil was used over a period of time. I have read numerous reports online of coconut oil use causing hair to become "hard" feeling and dry.

See Also

This blog post for more details