Origins of the Antifreeze Rumor
The urban legend that claims Mountain Dew contains antifreeze has several roots, primarily stemming from public mistrust and misinformation about complex ingredient lists. The most significant source of confusion involves the former use of brominated vegetable oil (BVO). BVO, which was once used as an emulsifier in citrus-flavored sodas, was also patented for use as a flame retardant in plastics. This dual-use claim led to fear-mongering and sensationalized headlines, causing many to mistakenly equate a food-grade emulsifier with a completely different, toxic industrial chemical. The rumor was also sometimes confused with entirely different incidents, such as when racing fuel containing methanol was accidentally mixed with Mountain Dew by teenagers, leading to tragic, but entirely unrelated, consequences.
The BVO Controversy and Removal
While BVO was used in small, FDA-approved quantities for decades in the U.S., public pressure led PepsiCo to announce its removal from Mountain Dew and other products. This additive was banned in Europe and Japan, which further fueled public scrutiny in the United States. In August 2024, the FDA officially revoked its regulation allowing the use of BVO in food products entirely. Despite the controversy, BVO is chemically distinct from toxic antifreeze compounds like ethylene glycol.
The Real Science: Ethylene Glycol vs. Food-Grade Ingredients
It is critical to distinguish between ethylene glycol, the primary component of automotive antifreeze, and the food-grade ingredients used in soft drinks. They have vastly different chemical compositions, functions, and toxicities.
Ethylene Glycol
- Formula: $C_2H_6O_2$
- Toxicity: Highly toxic and dangerous if ingested, even in small amounts.
- Use: Industrial applications such as automotive antifreeze, de-icing fluid, and manufacturing.
Mountain Dew Ingredients (U.S. Formulation)
- Key Components: Carbonated Water, High Fructose Corn Syrup, Concentrated Orange Juice, Citric Acid, Natural Flavor, Sodium Benzoate, Caffeine, Sodium Citrate, Gum Arabic, Erythorbic Acid, Calcium Disodium EDTA, Yellow 5.
- Toxicity: All ingredients are FDA-approved for consumption in the amounts used.
- Use: Provide flavor, color, preservation, and stability to the beverage.
Comparing Ingredients: Antifreeze vs. Mountain Dew
The fundamental differences between a toxic industrial chemical and a safe food product are clear. This table highlights how the myth originated from a misunderstanding of chemically distinct compounds.
| Feature | Antifreeze (containing ethylene glycol) | Mountain Dew (as per recent U.S. formulation) |
|---|---|---|
| Primary Use | Automotive coolant, de-icer | Carbonated soft drink |
| Toxicity | Highly toxic; ingestion is lethal | Non-toxic for consumption; contains FDA-approved ingredients |
| Key Ingredient(s) | Ethylene glycol | Carbonated water, high fructose corn syrup, natural flavors |
| Coloring | Often dyed for identification and safety | Yellow 5 (Tartrazine), an approved food coloring |
| Chemical Compound | Simple diol structure ($C_2H_6O_2$) | Complex mixture of water, sugars, acids, and other additives |
| Emulsifier | N/A | Previously BVO (brominated vegetable oil), now removed. BVO is not antifreeze. |
The Role of Additives in Mountain Dew
Several ingredients in Mountain Dew have also been the subject of scrutiny, though none relate to antifreeze. For example, Calcium Disodium EDTA is a chelating agent used to protect flavor by binding trace metal ions, which prevents spoilage. Another component, Yellow 5 (Tartrazine), is a food coloring approved by the FDA, though it has been associated with behavioral issues and allergic reactions in some individuals. Finally, the high sugar content, primarily from High Fructose Corn Syrup, has been linked to potential health concerns like weight gain and diabetes, but this is a separate issue from the antifreeze myth.
Conclusion: The Final Word on the Antifreeze Myth
To be perfectly clear, Mountain Dew does not contain antifreeze. The origin of this persistent urban myth lies in a misunderstanding of brominated vegetable oil (BVO), a food additive that was once used as an emulsifier. The rumor conflated this food-grade ingredient with a toxic, industrial chemical, leading to unnecessary panic. The manufacturer, PepsiCo, has since removed BVO from the recipe. All ingredients currently used are food-safe and approved by the FDA. While consumers may have valid health concerns related to sugar content or other additives, the inclusion of toxic antifreeze is definitively false.
For authoritative information on food safety regulations, consult the official U.S. Food & Drug Administration website: FDA.gov.
