What about food waxes?
Some fruit such as apples and plums produce their own natural waxy coating, called the cuticle, to help retain moisture and to form a barrier to prevent microorganisms from entering the fruit. About half of this natural wax is removed when produce is washed and scrubbed to remove dirt and chemical residues. Prior to packaging, food processors often apply wax to the surface of produce.
These commercial waxes are routinely applied to many fruits and vegetables to help preserve and protect them during shipping and storage. These waxes help prevent moisture loss, limit bruising and spoilage, improve appearance, inhibit mold growth, and extend shelf life. Aesthetics matter in the marketplace; consumers are drawn to shinier, glossier produce. Dyes may also be added to improve appearance.
Foods commonly waxed include: apples, oranges, tangerines, lemons, peaches, bananas, melons, avocados, cucumbers, tomatoes, bell peppers, eggplant, turnips, cassava and potatoes. Waxes are typically applied by dipping, brushing or spraying the produce. The amount of wax applied is small, perhaps a drop or two per item.
These waxes are edible; they must meet U.S. Food and Drug (FDA) regulations for food additives, and have been declared safe for human consumption. Produce that has been so treated must be labeled. Signs may read: “Coated with food-grade vegetable, beeswax, or lac-based wax or resin to maintain freshness.”
These waxes are typically esters of fatty acids combined with long-chain alcohols. Some of these coatings are synthetic (petroleum-based), while others are natural. These include: vegetable (from sugar cane or soy), as well as carnauba (from carnauba palm leaves), or bayberry wax (from bayberry fruit). Others originate from insects: beeswax and shellac (from the female lac beetle). Organic produce will not be coated with synthetic waxes, but may include shellac or carnauba wax. These are the waxes most commonly applied to apples. The waxy coating is typically not visible, but may turn white if the produce has been subjected to excessive heat and/or moisture.
Note that these waxes are not digestible by humans. We lack the ability to break down or absorb these waxy compounds.
The FDA does not recommend using detergent to remove wax. “FDA recommends washing fruits and vegetables under running water just before eating, cutting or cooking. FDA does not recommend the use of soap, detergent, or commercial produce washes” — according to the FDA’s website. However, you can use a 50-50 mixture of vinegar and water to remove the wax. Of course, the surest way to remove wax is to peel the fruit.
Some snack foods and candies, such as M&Ms, Skittles, Gobstoppers, Fruit Chews, Tic Tacs and Good ‘n Plenty are also coated with carnauba wax — which gives them a glossy finish.
Called the “Queen of Waxes,” as well as Brazil wax and palm wax, carnauba wax comes from the leaves of the tropical palm, Copernicia prunifera (copernica cerifera), native to Brazil. It is a complex mixture of aliphatic (waxy) esters, hydroxyl esters and cinnamic aliphatic diesters, along with free acids, free alcohols, hydrocarbons and resins.
It is also used in shoe polishes, furniture polish, automobile wax, and a coating for dental floss. Carnauba wax is widely used in the pharmaceutical industry to coats pills, and make tablets easier for patients to swallow. The coating adheres because the wax is insoluble in water. It is also the hardest of the commercial vegetable waxes.
Carnauba wax is used in the cosmetic industry in mascara and eye liner. It imparts the gloss to lip gloss and lipstick. Making Cosmetics labels it a “Non-gelling thickener, viscosity and consistency enhancer (provides good texture and stability due to high melting point), emollient and moisturizer, good skin protectant properties.” Its high melting point allows lipstick to resist melting, particularly if left in your purse in a hot car.
For those who make their own cosmetics, carnauba wax is even available on Amazon, where it is advertised: “Natural thickener with softening effect.”
The European Food Safety Authority (ESFA) reaffirmed the safety of carnauba wax at current usage levels, with its toxicity within the margins generally classified as No Observed Adverse Effect Levels (NOAELs). Their Scientific Opinion states: “The panel considered that carnauba wax would be predicted to not be significantly absorbed from the diet and that if hydrolyzed its main constituents could be absorbed and incorporated into normal cellular metabolic pathways. Based on the available data nd the lack of structural alerts on carnauba wax it was concluded that there is no concern for genotoxicity for carnauba wax. Subchronic and reproductive and developmental toxicity studies did not show adverse effects related to carnauba wax intake. No chronic toxicity or carcinogenicity studies were available on carnauba wax.” No data was obtained with respect to allergenicity, hypersensitivity, or intolerance. The ESFA concluded, “Overall the Panel concluded that long-term toxicity data on carnauba wax were lacking and therefore did not establish and ADI (Acceptable Daily Intake).”
And yet, the Material Safety Data Sheet (MSDS) for carnauba wax lists the product as “Very hazardous in case of ingestion”. No doubt this was determined for lab rats who ingested substantial quantities of carnauba wax. But note that data for carcinogenic effects, mutagenic effects, teratogenic effects and developmental toxicity are listed in Section 3 as “Not available.”
What exactly is an Acceptable Daily Intake? How much carnauba wax might a person ingest in a year? There seems to be little data on long-term toxicity for carnauba wax.
Best ways to wash produce
Wax can be removed from fruits and vegetables by washing in warm water and scrubbing with a brush. A study by the Connecticut Agricultural Experiment Station indicated that friction was more important than water temperature in removing residues. Produce with nooks and crannies such as broccoli or cauliflower or lettuce should be soaked in clean cold water for several minutes. For more about washing produce, see Food Safety Facts.
There are commercial washes such as Fit Fruit & Vegetable Wash — which claims to be 100% Natural and able to “remove 98% more pesticides, waxes, people-handling residues and other contaminants vs. washing with water alone.” The ingredients include Purified Water, Oleic Acid, Glycerol, Ethyl Alcohol, Potassium Hydroxide, Baking Soda, Citric Acid, and Distilled Grapefruit Oil. Fit is available as a spray bottle and soaking solution. Instructions call for the consumer to spray the solution to completely cover the produce, rub for one minute (or let sit for 2 to 3 minutes), then rinse under running water. For produce with irregular surfaces — such as broccoli or cauliflower — it is recommended to soak the items in diluted Fit for 2 to 3 minutes, then rinse.
Are these products necessary? The FDA’s website states: “Wash all produce thoroughly under running water before eating, cutting or cooking. this includes produce grown conventionally or organically at home, or purchased from a grocery store or farmer’s market. Washing fruits and vegetables with soap or detergent or using commercial produce washes is not recommended.”
Personally, I keep a spray bottle of 50-50 water and vinegar handy for washing fruits such as apples.