Why Is There Petroleum In My Breakfast Cereal?

If you have turned on the news or opened Twitter/X recently, you may have seen a lot of discussion about processed foods, additives, food dyes, etc. It has become a very hot topic that deserves a wide discussion, but what exactly do we mean by processed foods? What is THE PROCESS? As with most things in our modern life, food production for 6 billion humans means a lot of technology, infrastructure, and engineering. One of the most talked about aspects of processed foods are artificial food dyes that have become ubiquitous in the United States. How do Fruit Loops and Mountain Dew get their vibrant yellow color? Is it from Bananas? Lemons? Ground up butterflies?? No, it comes from….. petroleum?! Yup, it comes from oil, and the process for creating it (along with all other artificial dyes) is very much an industrial process.

Yellow 5, also known as Tartrazine, emerged from the early days of synthetic dye development, which began as chemists explored byproducts of coal tar in the mid-19th century. Coal tar is a thick, sticky byproduct of coal processing used for gas and coke production, and it was found to contain numerous aromatic hydrocarbons (complex organic compounds with a stable ring structure). These hydrocarbons became the starting materials for an entirely new class of colors that would change multiple industries forever.

The story of Yellow 5’s discovery, like that of many synthetic dyes, begins with a bit of serendipity in coal tar research. In the 1850s, chemists experimenting with coal tar found they could modify its compounds to create vibrant synthetic dyes, which were far brighter and more stable than natural dyes derived from plants or animals. Chemists discovered that by manipulating coal tar derivatives with various chemical treatments, they could create a wide range of colors—one of which was the brilliant, stable yellow that became known as Tartrazine or Yellow 5.

The turning point in synthetic dye discovery came with William Henry Perkin, a British chemist who, while attempting to synthesize quinine (an antimalarial drug), accidentally created the first synthetic dye, mauveine, in 1856. Perkin’s “mauve” discovery triggered an industry-wide race to develop more dyes, setting off a wave of research and experimentation with coal tar derivatives. Over the next several decades, chemists discovered methods to produce almost every color of the spectrum through synthetic means.

In this race, Tartrazine was one of the early colors created, as chemists tinkered with chemical compounds to produce yellow tones. Tartrazine specifically belongs to the “azo” dye family, named for the nitrogen-to-nitrogen double bonds (N=N) at its core, which give azo dyes their characteristic vibrancy. By adding different chemical groups, including sulfonate groups, and manipulating the structure of the molecule, chemists were able to create a stable, water-soluble yellow dye with a bright, appealing hue.

Once discovered, Yellow 5 quickly became popular for food, textiles, and cosmetics due to its stability, vivid color, and relatively low production cost. Its synthetic origin also meant it was not dependent on seasonal or geographical variations, unlike natural dyes, allowing for consistent quality and supply. The discovery of Tartrazine as a coal-tar derivative thus marked a significant advancement in the chemistry of color, cementing Yellow 5 as a mainstay in industries worldwide, particularly in processed foods where its vibrant color could enhance visual appeal and consumer interest.

Today, the production process involves several key chemical steps: diazotization, which introduces nitrogen to create a diazonium salt, followed by a coupling reaction that forms the dye’s signature azo bond, resulting in a stable, vibrant yellow color. To make the dye water-soluble, a sulfonation process adds sulfonate groups, allowing it to blend well in food and beverages.

After synthesis, the dye undergoes thorough purification and quality testing to meet food and safety standards before it’s packaged and distributed. With its vibrant color and stability, Yellow 5 is widely used in foods, cosmetics, and pharmaceuticals, providing the recognizable yellow hue seen in products from sodas to candies to medications.

Yellow 5 has been linked to all sort of health issues, a list too long to include here, but it’s just non-toxic enough to still remain legal in most places. Global health agencies are concerned to the point that Europe requires a warning on anything containing Yellow 5, it’s use is restricted in Canada, and there is a renewed push in the US to re-evaluate its extensive use.