Conventionally grown lemons and limes may be waxed to protect them from bruising during shipping. Plant, insect, animal or petroleumbased waxes may be used. Carnauba palm is the most common plantsource wax. Other compounds, such as ethyl alcohol or ethanol, are added to the waxes for consistency, milk casein (a protein linked to milk allergy) for film formers and soaps for flowing agents. Since you may not be able to determine the source of these waxes, this is another good reason to choose organically grown lemons and limes.