Basic, But Not Too "Basic"

Do you wash your hands? I hope your answer is yes! The main chemical in soap formation is sodium hydroxide (NaOH). You can find this chemical in many things you probably use everyday without even knowing it's there. Most of the time, its main job is to balance out the acidic properties of the other ingredients, just like in moisturizers (1). 

A surprising fact about sodium hydroxide is that it isn't found naturally, but it is produced from mainly salt and water (3). When a salt molecule is split using a technique called electrolysis, the free salt and water molecules can now come together to make sodium hydroxide (3). By itself, sodium hydroxide is actually quite corrosive; even though it is a basic chemical it can cause serious burns, pain, vomiting, blurred vision, and redness (4, 5). Being in direct contact with a concentration as small as 0.5% of sodium hydroxide can cause these problems (5). So you should always handle it very carefully or have someone assist you when dealing with sodium hydroxide. 

When you think of sodium hydroxide, you probably think it’s this boring, basic chemical that doesn’t do much. Surprisingly, sodium hydroxide is in a lot of things we use in our daily lives! You can find it in detergents, moisturizers, hair conditioner, and even soap (1). In soap specifically, sodium hydroxide plays an important role in its production. In order to make soap work, the sodium hydroxide binds to oils or fats, which turns it into soap (2). A single soap molecule had two sides, a top and a bottom; the top binds to water and the bottom binds to the dirt (2). When this process happens, you end up with a clean, dirt free area.

So, sodium hydroxide isn't that bad. By itself, it can be dangerous so you have to be careful, but in the products we use the manufacturers know just how much is needed to not cause burns or redness when we use things with sodium hydroxide in them. 

References

[1] Household Product Database. https://householdproducts.nlm.nih.gov/cgi-            

            bin/household/brands?tbl=chem&id=19&query=sodium+hydroxide&searchas=Tb

lChemicals (accessed March 22, 2016).

[2] Saponification - The Process of Making Soap.

http://amrita.olabs.co.in/?sub=73&brch=3&sim=119&cnt=1 (accessed March 22,

2016).

[3] Sodium Hydroxide. http://www.essentialchemicalindustry.org/sodium-hydroxide.html

(accessed March 22, 2016)

[4] The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals, 12th ed.;

Budavari, S.; O'Neal, M.J.; Smith, A.; Heckelman, P. E.; Kinneary, J. F., Eds.;

Merck & Co.: Whitehouse Station, NJ, 1996; entry 4857

[4] U.S. National Library of Medicine. Sodium Hydroxide.

https://pubchem.ncbi.nlm.nih.gov/compound/sodium_hydroxide#section=Top

(accessed March 21, 2016)