“…However, there are several parameters that can be considered when attempting to categorize them. Classifications based on their (a) origin, natural [ 39 , 40 , 41 , 42 , 43 ], synthetic [ 44 , 45 , 46 , 47 , 48 ], or semi-synthetic [ 44 , 49 ], and on their (b) chemical structure, alcohols [ 50 , 51 , 52 , 53 ], fatty acids [ 51 , 54 ], surfactants [ 48 , 55 ], esters [ 46 , 51 , 56 , 57 , 58 , 59 , 60 , 61 , 62 ], amides [ 45 , 62 ], and sulfoxides [ 63 , 64 ] are the most common.…”