What causes a colored pencil to smell?

Question

When using colored pencils, why is such a pungent odor produced? What chemical/substance creates the smell?

Answer 1

In order for the color to adhere to the paper often time a wax like substance is used in the pencil to hold the color powder together.  In turn, when disturbed by the action of writing , it releases a chemical with a pungent odor, or it smells rancid.  It is the oxidation of the grease in the wax.