*Originally published on July 30, 2010*
There’s been a lot of discussion lately about the pH of various products and how they affect the cuticle.
We all know that the pH of relaxers is very high (frequently above 10) and can actually have a disintegrating effect on the hair. But what about other products like baking soda (8), apple cider vinegar (5 to 7) and aloe vera juice (about 3.4)?
The Natural Haven addressed this topic in a recent article. To give some reference: the pH of water is 7. Anything above 7 is alkaline, below it is acidic. The lower the number the more acidic it is, the higher the number the more alkaline it is. The pH of hair ranges from as low as 3 to as high as 6.7–6.8.
Q1: Does pH raise or close cuticles?
There are two authoritative studies on this with pretty similar results. There is very little change to hair structure between the pH ranges of 4 to 9. Hair protein resists changes due to acid or base. Tests were performed using hydrochloric acid (powerful acid) and sodium hydroxide (a strong base).
1. Hair does not absorb noticeable amounts of acid or base between pH 4–10 ( J Soc Cosmet Chem, pp 393–405, 1981)
2. The cuticle separation distance is within the same range between pH 4 ‑9 (J Invest Dermatol 105: pp96-99, 1995)
Q2: Do the cuticles not open at high pH?
I insist on using correct terminology. The cuticle is not a door that can open and close. It is a protein whose structure can be affected causing it to lift. Yes the cuticle does lift around a pH of 10.
Q3: Are you really saying that hydrochloric acid and sodium hydroxide really do not affect hair?
In the range of pH 4 to 9 yes, there is not much change to hair. In fact soaking hair in water (yep plain ole water) for a long time (circa 10 minutes is long) actually yields greater change to the step height (see above) than acid or base.
Q4: What happens outside the pH 4 to 9 range?
At both low and high pH there appear to be structural changes to hair causing it to become more dense. This is thought to be a result of the acid or base changing the protein.Very high pH can actually dissolve hair.
And since we’re on the topic of pH, I wanted to share some information I found via LongHairCareForum.com. Now to give some perspective, alot of this information is dated (1999), so I don’t know if these pH levels still maintain, but it still gives pretty sobering insight.
The information gathered came from September 1999 edition of Consumer Reports and is not reported in any particular order. Its corresponding pH balance follows the product name/description.
1. TCB Bone Strait No-Lye Relaxer contains lithium hydroxide: 12.8
2. Revlon Realistic Extra Conditioning Crème Relaxer System contains sodium hydroxide: 13.2
3. Gentle Treatment No-lye Conditioning Crème Relaxer contains lithium hydroxide, guanidine carbonate and calcium hydroxide: 13.0
4. Soft and Beautiful No-lye Conditioning Relaxer Regular contains guanidine carbonate and calcium hydroxide: 13.1
5. Curl Free Natural Curl Relaxer contains ammonium bisulfite: 7.6
6. Dark & Lovely No-lye Conditioning Relaxer System contains guanidine carbonate and calcium hydroxide: 13.0
7. Revlon Crème of Nature No-lye Crème Relaxer System contains guanidine carbonate and calcium hydroxide: 13.1
8. African Pride Miracle Deep Conditioning No-lye Relaxer System contains guanidine carbonate and calcium hydroxide: 13.3
9. Soft Sheen Alternatives No-lye Relaxer System contains guanidine carbonate and calcium hydroxide: 13.3
10. Optimum Care No-Lye Relaxer guanidine contains guanidine carbonate and calcium hydroxide: 13.2
11. Rusk Radical Anti-curl Original Formula 1 contains Ammonium thioglycolate: 9.1
12. Revlon Realistic Crème Relaxer System 1 contains sodium hydroxide: 13.3
The following relaxer pHs were taken from, “Don’t Go Shopping for Hair Care Products Without Me” by Paula Begoun.
13. At One with Nature Botanical Strongends Sensitive Scalp Relaxer, Regular w/ Herbs and Moisturizers: 14
14. Dark & Lovely Beautiful Beginnings No-mistake No-lye Children’s Relaxer System Regular: 13
15. Dark & Lovely Plus Ultra-Deep Conditioning No-Lye Relaxer System: 12
16. Luster’s Pink Conditioning Super No-lye Crème Relaxer: 14
17. Raveen No-Lye Conditioning Crème Relaxer with Multiple Conditioners: 14
18. Revlon Crème of Nature No-Lye Crème Relaxer System: 13
19. Revlon Fabulaxer Multiple Conditioning No-lye Relaxer Kit: 13
20. Soft & Beautiful Just for Me No-Lye Conditioning Crème Relaxer, Children’s Formula: 14
21. Soft & Beautiful Super No-lye Conditioning
22. TCB Naturals No-Lye Relaxer, Regular with Olive Oil, Aloe and Henna: 14
The manufacturers provided the following relaxer pH’s:
23. Dark & Lovely Beautiful Beginnings Relaxer for Fine Hair: 10.25
24. Phytospecific Index 1 Relaxer for Fine Hair: 9–12
25. Phytospecific Index 2 Relaxer for Coarse Hair: 9–12
26. Lady Velvet Lye Relaxer: 10–13
Ladies, do you factor pH into your haircare?