What Is Meant by E100? Deciphering the Many Meanings

January 3, 2026 •

3 min read

A single code, E100, can refer to both a fuel for vehicles and a common ingredient in your food, creating considerable confusion. The meaning of 'E100' is entirely dependent on the context, which is why it’s important to distinguish between its various applications to avoid misunderstandings.

Quick Summary

The term E100 refers to different substances in various industries, most notably pure ethanol fuel used in specialized vehicles and the food coloring curcumin derived from turmeric. Other uses include industrial chemicals and a type of photographic film.

Key Points

Dual Identity: E100 most commonly refers to either 100% ethanol fuel or the food additive Curcumin, found in turmeric.
Fuel Characteristics: As a biofuel, E100 offers a high octane rating but has a lower energy density compared to gasoline, resulting in reduced fuel economy.
Food Coloring Source: E100 (Curcumin) is a natural yellow colorant used in a wide variety of food products, derived from the root of the turmeric plant.
Not for All Engines: Most conventional cars are not compatible with E100 fuel, with use restricted to specialized flex-fuel or racing engines.
Beyond Fuel and Food: Other, less common meanings include a blend of ethyleneamine chemicals used in industry and a type of professional photographic film.

E100 as a Fuel: 100% Ethanol

In the automotive and energy sectors, E100 refers to 100% ethanol fuel. This biofuel is a clear, colorless, and highly flammable liquid derived from plant materials like corn and sugarcane. It is often denatured with small amounts of gasoline or other additives like denatonium benzoate to make it undrinkable, avoiding liquor taxes and consumption. E100 is a renewable and cleaner-burning alternative to gasoline, which helps reduce greenhouse gas emissions and dependency on fossil fuels.

Properties and Uses of E100 Fuel

E100 fuel has a high octane rating (113 RON), which is beneficial for engine performance, particularly in high-performance or turbocharged vehicles. It also burns cooler than gasoline, which can prevent engine overheating. Despite these benefits, E100 has a lower energy density than gasoline, meaning vehicles typically achieve fewer miles per gallon when running on pure ethanol. Most standard passenger cars are not designed to run on E100 and require significant engine modifications to use it effectively. Flexible-fuel vehicles (FFVs) can use varying ethanol blends, but in North America and Europe, they are optimized for E85, not E100.

Brazil is a leader in E100 fuel adoption, with many flex-fuel vehicles capable of running on pure hydrous ethanol. This is thanks to decades of policy and infrastructure development focused on sugarcane-based ethanol production.

E100 as a Food Additive: Curcumin

In the food industry, E100 is the E number for Curcumin, a bright yellow, natural food coloring. Curcumin is extracted from the root of the turmeric plant, Curcuma longa, a member of the ginger family. It is a polyphenol known for its vivid orange-yellow color and is used to color a wide range of food and beverage products.

Applications and Properties of E100 Curcumin

Curcumin is used in many foods to impart a yellow hue. Some common examples include:

Mustard
Cheeses, butter, and margarine
Curry spices
Confectionery, jams, and jellies
Beverages and dairy products like yogurt and ice cream

Curcumin is sensitive to light and pH levels. In alkaline solutions (pH greater than 8), its color shifts from yellow to reddish-brown, while in acidic and neutral solutions, it remains yellow. It is only slightly soluble in water but dissolves well in ethanol and oils. The additive is generally considered safe and even offers some therapeutic properties, including anti-inflammatory and antioxidant effects.

Other Meanings of E100

Beyond fuel and food, the term E100 has a few other, less common meanings in specific contexts.

Ethyleneamine E-100

In chemistry and industrial processing, E-100 can refer to a complex mixture of ethyleneamines, including tetraethylenepentamine (TEPA) and others. This mixture is used in various industrial applications, such as:

Epoxy curing agents
Corrosion inhibitors
Asphalt additives
Lube oil and fuel additives

Kodak Ektachrome E100 Film

For film photographers, E100 refers to Kodak Ektachrome E100, a professional daylight-balanced color transparency film. This film is known for its fine grain, vibrant colors, and neutral tone scale, making it a popular choice for capturing highly detailed and richly colored images.

E100 Comparison: Fuel vs. Food Additive


Feature	E100 (Fuel)	E100 (Food Additive)
Composition	Approximately 98% ethanol, 2% denaturant	Curcumin, a natural extract from turmeric
Origin	Plant-based materials like corn or sugarcane	Extracted from the root of the Curcuma longa plant
Primary Use	Vehicle fuel, primarily for flex-fuel or specialized engines	Food coloring (yellow/orange), and flavoring
Key Property	High octane rating (113 RON), lower energy density	pH-sensitive color, antioxidant properties
Compatibility	Requires specific flex-fuel or race engines	Compatible with most foods, safe in specified quantities

Conclusion: Context is Everything for E100

The multifaceted nature of the term E100 underscores the importance of context in understanding scientific and technical language. While it can be a clean-burning biofuel offering a high octane boost for specialized engines, it is also the safe and widely used natural food coloring curcumin derived from turmeric. In more niche fields, it denotes a specific industrial chemical or a type of photographic film. Whether in an energy discussion, a food ingredient list, or a chemical catalog, the surrounding information is essential to accurately deciphering what is meant by E100. This is a common phenomenon with alphanumeric codes, and recognizing their different interpretations is the key to clarity. For further reading on flex-fuel vehicles, Wikipedia provides a comprehensive overview of how these technologies work with varying ethanol blends.

Frequently Asked Questions

No, you should not use E100 fuel in a standard gasoline car. E100 is intended for specific flex-fuel vehicles (FFVs) or race engines that are specially built to handle the fuel's properties. Using it in an incompatible vehicle can cause significant engine damage.

Yes, E100, or Curcumin, is a natural food colorant derived from turmeric and is approved for use in the food industry in many countries, including the European Union. It is considered safe for consumption within specified limits.

E100 is virtually pure ethanol (approx. 98% ethanol, 2% denaturant), while E85 is a blend of 85% ethanol and 15% gasoline. E85 is more widely available for flex-fuel vehicles, which are optimized for this blend, whereas E100 requires more specialized engine configurations.

Ethanol fuel is denatured, typically with a small amount of gasoline, to make it undrinkable. This serves two main purposes: to avoid being subject to beverage alcohol taxes and to prevent consumption.

As a food additive, E100 (Curcumin) is used in a variety of products to provide a yellow or orange color. Examples include mustard, cheeses, certain beverages, confectionery, and baked goods.

In addition to fuel and food additives, E100 can refer to a specific mixture of ethyleneamine chemicals used in industrial applications, such as epoxy resins and corrosion inhibitors. It is also the designation for Kodak Ektachrome E100 photographic film.

Yes, as a biofuel derived from renewable plant sources, E100 fuel burns cleaner than gasoline and can help reduce greenhouse gas emissions. It is considered a more sustainable alternative to fossil fuels.