Friday, July 26, 2013

A couple of chemistry myths making the rounds...

Baking soda and oil will not create a soap. There is a fascinating process called saponification during which oils and a very alkaline thing like sodium or potassium hydroxide are mixed together to create a soap. We can't extrapolate this to mean that every alkaline and every oil will mix to create a soap. Lye works because it's very alkaline - over 13 - and baking soda is pH 8 to 9.

Try this at home! Dissolve some baking soda in a small amount of water. (Acid and base reactions require water to create an aqueous solution.) Then add it - let's say 1 tsp - to something like 1 tbsp oil. Mix and mix and mix. You will not get soap. You could do equal amounts of 1 tsp baking soda and 1 tsp oil and you won't see a soap. (The same thing with boric acid - it's an acid, so it's not going to create a soap on its own.) If this were the case, why wouldn't we just throw some baking soda into our batch of oily dishes and create our own dishwashing liquid? It would be so much easier, cheaper, and better for the environment.

You cannot saponify the oils in your hair with baking soda. The pH of baking soda isn't great enough to create a soap. If you don't believe me, try the experiment above. It's okay if you like washing your hair with baking soda, but this is not the mechanism by which it might be working for you.

Alkaline + acid = doesn't always mean reaching pH 7 or neutral. This rarely the case. If you have something that is pH 14 (like lye) and pH 5, you aren't going to get to pH 7 or a neutral state. It depends on the pH and concentration of the acid and the pH and concentration of the base.

If you combine a strong acid and a strong base in equal amounts, you'll get a pH around 7. If you combine a strong acid and a weak base in equal amounts, you'll get a pH in the acidic range (and one that might not change at all, depending upon how weak your base). If you combine a strong base and a weak acid in equal amounts, you'll get a pH in the alkaline range (if it changes at all). If you combine a weak base and a weak acid, you'll have to do some work to see what you get. This is called a neutralization reaction, but it doesn't mean the end result is pH 7.

Besides, neutralizing something to pH 7 isn't a good thing. Let's say you have just enough of an alkaline thing and just enough of an acidic thing to get you to pH 7, is that really the best thing for that body part? If your skin is intended to be pH 4.5 to 5.5, neutralizing it to 7 is going to cause you great pain and misery. If your hair is intended to be pH 3.5 to 6, getting it to 7 is going to cause all kinds of cuticle lifting and damage.

The CEO of my pharmacy wrote an article in his company coupon book/newsletter a few weeks ago in which he stated that we could tell shampoo was toxic because it makes our eyes water. This is silly! The reason our eyes water near shampoo is because they have a pH of about 7.4 and body wash, facial cleanser, shampoo, and so on are around pH 4.5 to 6, which means they aren't similar pH levels. If we put coffee, baking soda, or orange juice in our eyes - natural and non-toxic things - you'll experience eye watering. If you get sand or an eyelash in your eye, we'll have watery eyes because of irritation.

And I'm sure you've seen the alkaline water stuff around. (I'm not linking to it because I don't want to give it more promotion.) Everything they say is pretty much untrue. Think about this - if you have gastric acid in your stomach (pH 1.5 to 3.5, so it could be considered a strong acid at 1.5 - reference) and you add weakly alkaline water to it, what's going to happen? (Strong acid plus weak base equals acidic pH levels.) Will the pH of your stomach change? And how can it possibly get to any other part of your body when it hasn't changed your stomach pH by a tiny bit? There's nothing of this alkaline water left mere seconds after you ingest it! And don't get me started on the idea of microclustering!

I'm not saying you need to take a degree in chemistry, but a little good and correct knowledge can be a powerful thing when you're assessing claims about products or processes! Do you have a question about a chemistry claim? Send it to me!

Related posts:
Chemistry Thursday: Let's take a look at pH
Chemistry Thursday: How to measure pH
pH (general)
pH and our skin care products
An aside: pH and lotions
A few thoughts for the day: ...pH of our bodies
pH and bath products

Related links:
Neutralization reactions (Wikipedia)
Neutralization reactions (Elmhurst University)


Diane said...

Hi Susan,'
A late post, I just wanted to share a very simple lotion that I make bi weekly.

H20 75%
Sodium lactate 5%

FCO 13.5

Germall .5
various goodies 1

This time I used sea buckthorn berry oil at about 10 drops then lemon ironbark EO and DISTILLED lime EO, about 5 drops each.

I work outdoors in a high desert environment with generally single digit humidity. I also have fair skin. The sbb is supposedly good for general maintenance and possibly regeneration of cells; the ironbark is a very mild and pleasant aldehyde (citral) which is an acknowledged insect repellent and this is "quenched" by an oil heavy on limonene (in all citrus but the cold pressed EOs are often phototoxic and the lime is the only distilled citrus I know of.

I am using sodium lactate since I am out of honeyquat, my usual extra humectant. I vary the water proportion, about 85% separates my crèmes from my lotions and I vary the oils (although some coconut oil is always used) and I vary the emulsifiers; I'm happier with BTMS than Polawax; it's noticeably drier going on.

I use this freely before going out, some during and again freely after the sun exposure. I'm not making any claims but I have been out in the sun a whole lot for two years and never had a sunburn.

I'm happy with this and sometimes use a lot more goodies but generally just the emulsion and a bit of EOs and I'm good. Your blog was/is my inspiration to start all this. Keep on!

Bailey said...

Hi Susan,

I am reminded of a time I went camping with SCA friends. Turns out, after my group had finished fixing breakfast over the fire, we discovered no one had brought dish soap. Since one of the things cooked in the pan was (streaky) bacon, and it was over an open fire, I simply scooped some of the ashes into the pan, added a bit of water, swirled it around a bit til it was cool enough to touch and scrubbed with a rag, then rinsed it out. Clean as new! My fellow campers were amazed, and I reminded them what soap was originally made from. *impish grin*


Susan Barclay-Nichols said...

Hi Bailey! Great story! I've used it in today's Weekend Wonderings!

Hi Diane. Why are you making it bi-weekly? Why not make a giant batch and store it. This lotion could last up to two years, depending upon the goodies. This looks like a great and simple recipe - a wonderful example that shows that we don't need to get really complicated to make something awesome! One thing that jumps out to me - sodium lactate is sun sensitizing above 2.5%. Just be careful!

Diane said...

Thanks for the heads up, Susan.

I make it biweekly to keep my chops up! also, just like eating a variety of vegetables I think it's optimum to change carrier oils, emulsifiers etc.

BTW, the EO chart from Ananda still talks about ml and not mg - and I don't agree with it. Anyone who has lost circulation in the hand waiting for a Vetiver drop to make a move and then find it to be quite close numerically to lemon, say, or tea tree, on the chart, might find her faith drawn into question.

and some oils such as clove and cinnamon have been proven effective in incredibly small proportion

So I play with essential oils biweekly - or so

I was trying to make deodorant with your gel stick recipe but as of now am discouraged by the difficulty getting the ingredients. Currently I am using a hand sanitizer with aloe gel - I just remembered I have some Crothix ...

Diane said...

..but maybe that's too much information . . .