Diesel fuel has become an essential part of modern life. It powers our trucks, trains, ships, generators, and equipment. While gasoline is typically stored in red containers, diesel fuel is often stored in yellow containers. This distinctive yellow color serves an important purpose – to quickly identify diesel fuel and prevent accidental misfueling. In this article, we’ll explore the history behind diesel’s yellow gas cans and drums, the science behind the color, and the safety benefits of this standard color-coding system.
The History of Yellow Diesel Cans
Prior to the 1950s, there were no standardized color codes for fuel containers. Gasoline and diesel cans came in all colors and were often indistinguishable. This resulted in diesel engines frequently being misfueled with gasoline, which can cause serious engine damage.
In the 1950s, the American Trucking Associations (ATA) partnered with the United States government to develop a standardized system of colors to identify petroleum-based fuels. This was done through a joint effort between the ATA, the Society of Automotive Engineers (SAE), and the American Petroleum Institute (API).
They decided that red would be designated for gasoline and yellow for diesel fuel. This color-coding system was formally adopted in 1957. The familiar yellow diesel can was born.
The Science Behind Yellow
But why was yellow chosen? The color yellow stands out against other colors and is easy to spot. This high visibility makes it ideal for identifying hazards and marking caution.
In optical science, yellow has the highest luminance of all colors in the visible spectrum. This means it seems brighter to our eyes and draws attention more easily. Its luminous intensity helps the yellow diesel cans clearly stand out from gasoline cans.
Psychological research has also shown that yellow elicits feelings of optimism and confidence. Seeing the bright yellow can may give diesel equipment operators a sense of safety and reassurance that they have the right fuel for their engines.
| Color | Wavelength range (nm) | Luminance |
|---|---|---|
| Red | 620-750 | Low |
| Orange | 590-620 | Medium |
| Yellow | 570-590 | High |
| Green | 495-570 | Low |
| Blue | 450-495 | Low |
| Violet | 380-450 | Low |
This table shows the luminous intensity of colors in the visible light spectrum. Yellow, with its wavelength range of 570-590 nm, has the highest luminance of all the colors.
Safety Benefits of Yellow Diesel Cans
Using yellow containers for diesel provides three major safety benefits:
- Prevents misfueling accidents: Distinguishing diesel from gasoline reduces the chance of accidentally pouring gasoline into diesel engines. Gasoline can cause catastrophic failure in compression-ignition diesel engines.
- Avoids fuel mix-ups: Keeping diesel and gasoline physically separated ensures fuel purity. Mixing diesel and gasoline can create an unusable blend.
- Improves visibility: The high visibility of yellow containers helps prevent spills. Yellow cans are easy to spot if tipped over, punctured, or leaking.
By quickly signaling “caution, diesel fuel only”, the yellow cans have prevented untold engine disasters and fuel waste over the past 70 years.
Diesel Can Color Regulations
While voluntary industry standards led to the initial adoption of yellow diesel cans in the 1950s, federal regulations have since solidified yellow as the required color for diesel fuel containers in the United States and Canada.
In the US, diesel cans are regulated by the Occupational Safety and Health Administration (OSHA). OSHA Standard 29 CFR 1910.144 states that diesel “shall be kept in containers painted yellow with BLACK letters ‘DIESEL’.”
In Canada, the Canadian Centre for Occupational Health and Safety echoes this requirement. Diesel containers must be yellow with a black stripe and lettering identifying the contents as “diesel fuel”.
However, certain exceptions are made for fuel tanks permanently mounted on vehicles and equipment. So you may see excavators with black diesel tanks, for example. But external diesel cans and drums still must meet the yellow color mark.
Diesel Container Labeling
In addition to being yellow, diesel cans and storage tanks must contain explicit wording identifying that they contain diesel fuel. This labeling requirement serves as a secondary visual indicator.
Required labeling text includes:
- “Diesel fuel”
- “Low sulfur diesel fuel”
- “Ultra low sulfur diesel fuel”
The label lettering must be black and a minimum of 1 inch high. On smaller diesel cans, such as 5-gallon jugs, the lettering can be proportionally smaller but still clearly legible.
Other Diesel Container Standards
Beyond being yellow and labeled, diesel cans and drums must meet other specifications for safe fuel handling:
| Specification | Requirement |
|---|---|
| Material | Must be non-reactive to diesel, such as steel or high-density polyethylene plastic |
| Leak proof | Containers must seal to prevent spills and evaporation |
| Vents | Caps must allow venting to prevent pressure buildup |
| Durability | Construction must withstand wear and tear |
| Labeling | Contents marked clearly as diesel fuel |
Meeting these physical standards ensures diesel cans remain intact, sealed, and properly labeled through repeated handling and use.
Diesel Container Sizes
Diesel fuel containers come in a range of sizes to suit different applications:
- 5 gallons – Portable cans for small engines and generators
- 10 gallons – Larger portable cans for tractors and machinery
- 30-55 gallons – Drums for refueling at shops and garages
- 100-500 gallons – Intermediate bulk storage tanks
- 1,000+ gallons – Large fuel tanks for farms, industry, and bulk fuel supply
Regardless of the size, diesel containers must follow the yellow color standard and labeling requirements.
Global Use of Yellow Diesel Cans
While standardized in North America, yellow diesel cans are also common in many other countries. However, localized regulations and custom vary region to region globally.
Europe largely follows the yellow diesel can standard, especially for retail sale and transport. However, some European countries allow different colors for stationary diesel storage tanks.
In the United Kingdom, yellow is mandated by regulation for diesel jerry cans. But larger storage tanks are often black or green.
Australia closely adheres to the yellow standard for diesel. But in nearby New Zealand, no container color is mandated by law. Yellow is customary for diesel in New Zealand, but not universal.
Parts of Asia and Africa frequently use black or other colors for diesel cans and tanks. However, yellow diesel cans are becoming more widely available and used.
So while exceptions occur, yellow is considered the international norm for diesel fuel containers in most countries.
Alternative Diesel Colors
While nearly all retail diesel cans and drums sold today are yellow, colors have varied historically. What other colors have been used for diesel?
Black
Before color standardization, black was a common color for all fuel cans, including diesel. Black is still seen today, especially for stationary diesel tanks. It provides UV protection to help reduce fuel degradation.
Green
Olive green was previously used for some diesel containers, especially military surplus cans. Green provides camouflage and mimics typical paint colors used on combat vehicles and equipment.
Blue
Blue has been used in some regions to denote high-sulfur “dyed” diesel for off-road use. This distinguishes it from clear road diesel. However, blue is not common for diesel now.
White
White tanks and cans were historically used for various petroleum products. White is still seen for kerosene containers. But white diesel tanks could cause fuel confusion.
While other colors have existed, the superiority of yellow for visibility and recognition has made it the universal color for diesel cans and tanks.
Confusion With Kerosene and Other Fuels
Despite standardization, diesel cans are sometimes still confused with containers for other petroleum products. What other fuels have yellow containers besides diesel?
Kerosene
Kerosene is probably the most common source of confusion with yellow diesel cans. Some kerosene containers are yellow, while others are white or blue. Yellow kerosene cans should always be distinctly labeled “kerosene” to avoid mix-ups.
Heating Oil
Heating oil is essentially the same product as diesel fuel without road taxes added. So heating oil cans are also typically yellow. However, they should display a heating oil label to prevent mistaken use in engines.
Ethanol
E85 ethanol blend fuels are sometimes stored in yellow containers, especially at fueling stations offering ethanol. Yellow E85 cans should be labeled as “Ethanol” or “E85”.
Overall, explicit labeling is important whenever a non-diesel product is stored in a yellow container to prevent use in incompatible engines and equipment.
Conclusion
The distinct yellow color of diesel cans and tanks has become an indispensable visual cue for engine owners and equipment operators worldwide. Since being popularized in the 1950s, yellow has served as a vital safety standard.
The high visibility and luminance of yellow make it instantly recognizable against other container colors. This allows workers to quickly identify diesel fuel and avoid disastrous mix-ups with gasoline or other products.
Mandated by regulation in North America and widely adopted internationally, the yellow diesel can is now a ubiquitous sight wherever diesel engines are running. With its unique ability to signal “caution” and “diesel fuel only”, the yellow diesel container continues to prevent fuel mishaps and drive safety on worksites and roads worldwide.
