The chemicals have to be in contact with each other in order for any type of chemical reaction to take place. One of the most common examples of a chemical reaction is the rusting of a fence. The combining of the metal and the oxygen causes bonds to break and new ones to be created, which results in the creation of iron oxide or rust.
The ear canal cleans itself with a waxy secretion called cerumen. Cerumen is resistant to water, sticky (to trap dust) and migrates out of the ear canal to self-clean the ear. Sometimes, the wax builds up and causes symptoms, including mild deafness and a sensation of fullness inside the ear.
In the outer part of the ear canal, cells produce a wax called cerumen that traps particles of dust and dirt. The wax also repels water, protecting the delicate eardrum from damage. The wax is moved outward gradually by the lining of the ear canal, carrying any dirt it has trapped. Eventually, the wax dries and falls out of the ear in small, unnoticeable flakes. Normal production of earwax is healthy and good for your ears.