1. What is triethanolamine?
It is a base which does contain three alcohol molecules but it is not an alcohol.
2. Why is TEA found in gels?
It is used to adjust the pH to a neutral region so that the gel can actually form. Most often you will find both TEA and carbomer listed. These two are the backbone of most commercial gels. The TEA is added to water to adjust the pH and carbomer (a polymer) helps to turn the liquid phase (aloe vera or water or both) into a gel. I found a video showing exactly this. Do note how little TEA is required!
3. Does TEA form sodium hydroxide in gel?
Honestly the chemistry when you have 5 or more ingredients is quite complex and it would be highly inaccurate to speculate on this without having done lab tests. Suffice it to say though that even if you directly added sodium hydroxide (which can be done as it too is a base and we need the base to bring the pH to neutral!), this does not mean that your hair will be relaxed. The bottom line is that bases are used for pH adjustment for hair lotions, conditioners and gels which are not intended to relax hair.
4. IF there is sodium hydroxide in the gel, can it give you cancer?
Currently, sodium hydroxide is not classed as a carcinogen. I say currently because information may change but so far, it is not known or listed directly as a carcinogen. This does not mean that it is safe and can be used willy nilly! In high concentration (e.g relaxers), it most definitely is dangerous and associated with skin damage but again not everyone who uses a relaxer ends up with burns, with proper precautions it can be used.
5. Does TEA contain nitrosamines and can this give you cancer?
TEA can indeed contain nitrosamines and nitrosamines are known to be carcinogenic, this is widely accepted. However, cosmetic grade TEA from Dow Chemical Co. has previously been analysed independently and there was no detectable nitrosamine across several batches (J Soc Cosmet Chem, pp 237-252, 1980). The word 'detectable' is important because the instruments used can find nitrosamines if there is at least around a nanogram (1 billionth of a gram) present......yes really that little! Therefore if cosmetic grade TEA of a similar standing is used for the gel, it will probably have no detectable nitrosamine.
6. Is TEA safe?
It is up to you to decide for yourself. In the same way that it is up to you to decide whether parabens are safe or not. I only provide the information :)
If you are worried about nitrosamines then do read up more on frying meat, eating smoked and preserved meat e.g bacon etc as if you have these regularly, your hair gel should be the least of your concerns.
7. Do I (me, Jc) use TEA?
Yes, I am currently liking aloe vera gel (a commercial one) with TEA and preservatives. It would be nice to use the plant leaf directly but that is filed under too much work for me. I also have no issues with parabens or formaldehyde precursors as preservatives..........I say this just so you can see where I lie in the spectrum :)