Cerumen is produced in the outer third of the cartilaginous portion of the human ear canal. It is a mixture of viscous secretions from sebaceous glands and less-viscous ones from modified apocrine sweat glands. The primary components of earwax are the final products in the HMG-CoA reductase pathway, namely, squalene, lanosterol, and cholesterol.

There are two distinct genetically determined types of earwax: the wet type, which is dominant, and the dry type, which is recessive. Asians and Native Americans are more likely to have the dry type of cerumen (grey and flaky), whereas Caucasians and Africans are more likely to have the wet type

http://en.wikipedia.org/wiki/Earwax