- Urea-hydrogen peroxide, UHP
- Hydrogen peroxide, H2O2
Published June 2009
Ear wax slowly oozes from sebaceous glands in the ear and is a mixture of squalene, lanosterol and cholesterol. Depending on its composition, earwax can vary from a runny oil to a hard plug.
Urea-hydrogen peroxide, UHP (aka percarbamide) is the active ingredient and Otex contains 5% UHP which is a 1:1 combination of urea and hydrogen peroxide. These molecules cling to each other by interlocking hydrogen atoms and this stabilises the hydrogen peroxide which is normally a liquid and prone to decomposition to oxygen and water. In the ear UHP penetrates the earwax and there it reacts to release bubbles of oxygen gas which break up the wax. UHP is added to some cosmetics, toothpastes and pharmaceuticals as a means of keeping the product germ-free. UHP is used in chemistry as an oxidising agent.
Urea (NH2)2CO (aka diaminomethanal, carbamide) is present in human urine and produced by the liver as a way of getting rid of excess nitrogen from the body. It is also produced on a vast scale (100 million tonnes per year) by industry from ammonia and carbon dioxide and used mainly as a fertilizer. It is also used to make urea–formaldehyde adhesives and plastics like melamine.
Hydrogen peroxide, H2O2 is a safe and powerful disinfectant and oxidising agent produced on a large scale by a process devised by the Nazis who needed it to launch V1 rockets (flying bombs) against London in World War II. In July 2005 it was again used to attack London, this time by four terrorists who exploded home-made triacetone triperoxide bombs that they made by combining hydrogen peroxide and acetone, the solvent of nail varnish remover. (They killed 56 people and injured 700.) Hydrogen peroxide has many uses, from bleaching hair and paper to removing stains and disinfecting wounds. In high concentration (90%) it can be used as a rocket fuel. When in the presence of a silver or platinum catalyst it releases massive amounts of energy as it decomposes to oxygen and steam. The bombadier beetle makes hydrogen peroxide as the fuel it uses to squirt an irritant spray to defend itself.
8-Hydroxyquinoline (aka quinolin-8-ol) is a powerful antibacterial agent and it was formerly used as a spermicide. It is also produced naturally by the roots of the invasive white knapweed which affects crops in North America. It releases 8-hydroxyquinoline to discourage other plants from growing nearby.
Glycerol (aka glycerine, propane-1,2,3-triol) is the anchor molecule to which long hydrocarbon chains attach themselves in the formation of fats and oils (lipids). It is a useful solvent, which is its role in Otex. Glycerol provides the beads of perspiration on the brows of movie actors because it doesn't evaporate like normal sweat. When glycerol is reacted with concentrated nitric and sulfuric acids it forms nitro-glycerine which is the explosive component of dynamite.