Emollient

Good
ESTER

A compound formed from the reaction between an alcohol and an acid via the elimination of water. Triesters (groups of three esters) form the backbone of many fats, waxes, and oils that have emollient and skin-conditioning properties. Almost all of the esters used in cosmetic products are non-sensitizing and in most cases are quite beneficial for dry skin.

Reference for this information:

A Dictionary of Chemistry, Third Edition, Oxford Paperback, 1996