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"Being an inventor, I invented my way out of it." The chemist Robert H. Black is the inventor of Clean Shower, a spray-on product for rinsing the shower after each use. Black was motivated by his wife, who made him clean the shower. The inventor realized that this is a particularly nasty task, and that any invention to ease this task would have tremendous market potential.

Since Clean Shower came onto the market in 1995, sales have indeed soared. Annual U.S. retail sales for Clean Shower and competing brands such as Shower Shine, Mist Away and Fresh Shower were already up to $70 million in 1998.

Judging by sales figures, these products appears to do what they were designed for. This raises the question how exactly these shower cleaners work. The key to understanding this is knowledge of the types of residues are formed in the shower, and the way they are deposited. Organic residues consist of oils and debris from the body, usually coated with soap or shampoo. There are also inorganic deposits like calcium, magnesium and iron from the water. If left to dry, these deposits build up over time. The damp environment is also a breeding ground for a third type of residue, namely mold and mildew.

According to the patent, one important ingredient of Clean Shower is Antarox BL-225 surfactant (a mixed ethylene glycol ether nonionic surfactant). This compound lowers the surface tension of the water droplets on the shower walls, causing them to coalesce. This is called sheeting action: the water glides down the surface in a thin film.

A second important ingredient is Hamp-ene diammonium EDTA, a chelating agent. This compound sequesters the ions of the inorganic salts, rendering them soluble. Most of the inorganic salts are washed away by the sheeting action. Some of the inorganic salts remain behind, but the chelating agent and surfactant act as a barrier against residue buildup; next time the shower is used, the remaining salts are washed down with the chelating agent and the surfactant.

The sheeting action alone is not sufficient to avoid the growth of mold and mildew and therefore, Clean Shower also contains a disinfectant. Other ingredients are isopropyl alcohol, which helps to dissolve all the ingredients in water and to remove oily human debris, fragrance, and water.

Brands other than Clean Shower use different compounds to achieve similar results and not infringe on patents.


Factual sources:

Chemical & Engineering News - December 3, 2001
US Patent 5,910,474: Method of rinsing showers clean

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