Soap: how is it made, and what it's made from?
Definition: Soap is a cleansing agent made from the interaction of fats and oils with alkali.
How does it work?
Most soaps remove grease and dirt because some of their components are “surfactants” (surface-active agents). Surfactants have a molecular structure that acts as a link between water and the dirt particles. This loosens the particles from the underlying fibers or surfaces to be cleaned. One end of the molecule is hydrophilic (attracted to water), and the other is hydrophobic (attracted to substances that are not water soluble). This peculiar structure allows soap to adhere to substances that are otherwise insoluble in water. The dirt is then washed away with the soap.
Much of what is called “soap” today is not really soap at all, but harsh, petroleum-based detergent that dries and irritates our skin and can cause inflammation, itching, and burning. The most common “fragrances” used are also synthetic petrochemicals that trigger allergic reactions in many of us. Toxic colorants and other substances are also often added to what is sold as “soap.”
How is soap made?
Soap is made by combining fats and oils, which contain fatty acids, with lye, which is alkaline. The strong alkali splits the fats/oils into fatty acids and glycerin. Then the sodium (or potassium) part of the alkali joins with the fatty acid part of the fat or oils, forming a salt that we call "soap." Technically, soaps are sodium or potassium fatty-acid salts, produced from the hydrolysis of fats in a chemical reaction called saponification.
Synthetic "built" detergent, containing a surfactant detergent as the basic cleaning ingredient and a chemical “builder” that makes the surfactant more efficient, was first introduced in the U.S. in 1946. Phosphate compound builders vastly improved laundry-cleaning performance,and by 1953, detergent sales in this country surpassed those of actual soap. Synthetic detergents have now almost entirely replaced soap-based products for washing dishes and laundry and doing household cleaning.
Why are phosphates important to know about?
Phosphates are nutrients that stimulate overgrowth of algae, which deplete the supply of oxygen in contaminated waters, destroying plant and fish life. It is estimated that 50 to 75 per cent of the phosphorus in our lakes and rivers comes from detergents. By 1983 over 2 million tons of phosphorus were used annually in the US for detergents, with the average American contributing from 1.5 to 2 pounds of phosphorus per year to our surface waters. Today’s use is even greater. One pound of phosphorus can stimulate the grow 700 pounds of algae.
In 1970 Congress “strongly recommended” that the phosphate content of detergents be immediately reduced, and that it be phased out entirely by 1972. Municipalities in several states passed laws limiting detergent phosphate content or even banning it altogether, and Canada limited detergent phosphate content to 2.2%. Proctor & Gamble, the makers of Tide, the most popular American detergent, led a successful lobbying effort against a federal ruling to lower phosphate content to 8.7%, as U.S. detergent makers to agree to reduce detergent phosphorus concentrations to 8.7% voluntarily. Many companies, however, have not kept this promise.
What can I do to help the environment?
Let companies that still use phosphates know you’re not buying their products for this reason. Use liquid organic cleaners instead. (And keep all cleaning products out of the reach of small children, as the ingestion of some brands has proven to be fatal.)
We have even taken thoughtlessly to washing ourselves with detergent. Most of the products now used for bathing (as well as for shampooing and cleaning our teeth) are actually synthetic detergents. They are popular because they foam abundantly, work well in hard water, and don’t leave the “soap scum” that forms when soap reacts with the calcium in hard water. Because their advertising refers to them as “soap,” few people realize that they are in fact detergent.
The bar “soaps” contain additional chemicals added to make them hold their shape and move smoothly through factory machinery, and the naturally humectant glycerin that is a byproduct of natural saponification is removed. The liquid “soaps” are composed almost entirely of chemicals of varying toxicity. Both the bars and liquids are harsh and drying to our skin. They also contain petrochemical fragrances and colorants, many of which are toxic and some of which are actually carcinogenic.
