With the featured capability to allow the fusion of oil and water, surfactants are widely used in foaming, emulsification, lubrication, washing, sterilization, anti-static functions and for other purposes. The applications are indeed quite varied, particularly in respect of cleaning and body care products, such as laundry and dish detergents, shower gel, shampoo, toothpaste and a host of others.
Are surfactants harmful to human bodies? It is not possible to posit a general summarization covering all possible situations because surfactants can be divided into "natural surfactants" and "chemical-synthetic surfactants". All surfactants have both hydrophilic and lipophilic “bi-polar qualities”, but their effectiveness will differ in terms of strength or weakness. Whether a given surfactant is harmful to human bodies does not depend on its "lipophilic and hydrophilic" nature but rather on its chemical structure!
"Natural Surfactants" from Mother Nature In ancient times, there was no great variety of cleaning agents. People came to discover and make use of a variety of natural cleaning substances such as the ashes of plants and wood for cleaning clothes, rice water and Chinese Honey Locust for shampooing and bathing. Such substances taken from nature were prized for their cleaning and decontamination effects. With the development of human civilizations, people began to learn how to use animal or vegetable fats together with alkali, thereby bringing about natural saponification at room temperature. The soap produced thus emerged as a natural surfactant that was not harmful by nature to the human body and decomposed easily and naturally, leaving the ecology and environment completely undamaged.
"Chemical Synthetic Surfactants" from Inexpensive Petroleum By-Products Chemical synthetic surfactants first appeared at the beginning of the 19th century in Europe, and were at the time limited solely to industrial use. By 1933, the United States had succeeded in extracting petrochemical surfactants from petroleum by-products (tar). Thereafter, in tandem with the popularity of washing machines, petrochemical synthetic detergents can now be found in virtually every household! The earliest chemical synthetic surfactant was a “hard” surfactant known as ABS. Because it could not decompose easily in rivers, its foam pollution became a public hazard that proved seriously harmful to ecosystems. The problem was significantly alleviated by the development of LAS, a more easily biodegradable “soft” surfactant than ABS.
However, the new surfactant was still not “perfect”, and therefore non-ionic, anionic, cationic, and zwitterionic surfactants have subsequently been developed. Even so, the modular structures of all these new chemical synthetic surfactants are not found in nature, leaving them highly resistant to microbial decomposition. When we use these detergents for household cleaning and bathing, they will be discharged into nature, with the net result that these decomposition-resistant chemical synthetic surfactants will be eaten or absorbed by animals and plants, and then transported, toxic chemicals and all, back into our bodies through the food chain! And there they will stay, gradually accumulating and exerting their bad effects on our hormone and secretion systems, resulting in physiological system imbalance and leading to diseases!
In general, our living has improved in tandem with the progress of science and technology. We can also find more and more chemical synthetic surfactants made through the artificial synthesis of chemicals because of the low cost of producing cleaning detergents that are more effective with better solubility, higher cleansing power and greater convenience when compared with traditional cleansing methods, including soap. As a result, these chemical synthetic surfactants have been widely used in our daily lives. However, the harm thereby caused to our bodies and the environment has also been discovered gradually and confirmed in one case after another in numerous experimental studies. In the future, perhaps more and more synthetic chemicals will be identified as carcinogens, compelling us to avoid the use thereof and to switch over to natural surfactants, or to detergents without any chemical synthetic additives in order to safeguard our personal health and to protect the environment of our planet.