How safe is e85 (Ethanol) and other alternative fuels?

Most people are familiar with gasoline, so they rarely question its safety. However, people who are unaccustomed to alternative fuels may have misconceptions or doubts about their safety in vehicle applications. Some safety issues associated with the use of alternative fuels are outlined here.

Biodiesel is biodegradable, meaning it dissipates quickly after a spill. It has a high flashpoint and low volatility, so it does not ignite as easily as conventional diesel, increasing the margin of safety in its handling. Biodiesel degrades four times faster than conventional diesel and is not particularly soluble in water. It is nontoxic, so it is safe to handle, transport, and store. As with all alternative fuels, adequate training is recommended to operate and maintain biodiesel vehicles. (Source: EPA Biodiesel Fact Sheet, 6698.)

Compressed Natural Gas (CNG)
The fuel is odorless, and odorants must be added to ensure users can detect leaks and spills. In the event of a leak, the gas will rise to the ceiling and create a potential risk in enclosed areas. Sturdy, heavy storage tanks must be used to avoid possible hazards from the high-pressure storage.

Electrical circuits are self-contained and grounded to prevent the risk of shock from the vehicle frame. Electric vehicle battery packs store enough energy to produce a dangerous, even lethal shock. Electrolytes in the batteries may cause chemical burns, so protective gear must be worn when handling the batteries.

E85 (Ethanol)
If used in an E85-compatible vehicle, E85 is as safe as gasoline.

Liquefied Natural Gas (LNG)
The fuel is cooled cryogenically to -260F. At this temperature, bodily contact with the liquid fuel, cold metals, or cold gas can cause cryogenic burns (frostbite). Methane gas detectors must be installed to detect leaks because odorants cannot be added to LNG.

Liquefied Petroleum Gas (LPG)
Strong tank construction is required, but the pressure hazard is less than with CNG. LPG should be odorized, and detectors are recommended to help detect leaks or spills. The fuel is extremely volatile, and LPG fires burn twice as hot as gasoline fires.

Methanol is corrosive to several metals, rubberized components, gaskets, and seals. Low flame luminosity makes M85 fires difficult to detect in the daylight. Unhealthy exposure can occur through fume inhalation, ingestion, or direct contact with skin.

Ethanol Fuel, E85 Specifications and Handling

The American Society of Testing and Materials (ASTM) has developed E85 fuel specifications to ensure proper starting, operation, and safety. Please refer to the table below for ASTM D5798-99 Standard Specification for Fuel Ethanol for Automotive Spark-Ignition Engines.
This table of minimum commercial standards is also found on page 10 of the Handbook for Handling, Storing, and Dispensing E85 (PDF 3 MB) Download Adobe Reader. Please ensure the fuel delivered to your storage tank is guaranteed by your supplier to meet these standards. Include this spec as a requirement in your supply contract.

E85, like gasoline and diesel fuels, is seasonally adjusted to ensure proper starting and performance in different geographic locations. For example, E85 sold during colder months often contains 70% ethanol and 30% petroleum to produce the necessary vapor pressure for starting in cold temperatures. An E85 fueling site operator typically cannot carry over summer-blend E85, but rather must "blend down" any remaining summer fuel to make an E70 mixture. This may be done with relative ease by adding additional gasoline to the storage tank. There is no concern with carrying over winter-blend E70 into warmer months as flexible fuel vehicles operate on any blend of E85 and gasoline in during warmer times. For retail service stations, seasonal fuel adjustments are handled automatically at the wholesale fuel terminal.

Please refer to the Handbook for Handling, Storing, and Dispensing E85, Table 3 (p. 10) and Appendix A (pg. 22-23), for seasonal blending requirements in your area. In Table 3, the Value of Class refers to the Volatility Class by Month found in Appendix A. We encourage you to provide a copy of this reference guide to your personnel, equipment, or fuel suppliers or any prospective service station that will be working with E85.

Table 3. ASTM D 5798-99 Standard Specification for Fuel Ethanol for Automotive Spark-Ignition Engines
PropertyValue of ClassTest Method
ASTM volatility class123N/A
Ethanol, plus higher alcohols
(minimum volume %)
797470ASTM D 5501
(including denaturant) (volume %)
17-2117-2617-30ASTM D 4815
Vapor pressure at 37.8�C
ASTM D 4953
D 5190
D 5191
Lead (maximum, mg/L) D 5059
(maximum, mg/L) D 3231
Sulfur (maximum, mg/kg)210260300ASTM D 3120
D 1266
D 2622
(maximum, volume %)
Higher aliphatic alcohols, C3-C8
(maximum volume %)
Water (maximum, mass %)1.0ASTM E 203
Acidity as acetic acid
(maximum, mg/kg)
50ASTM D 1613
Inorganic chloride
(maximum, mg/kg)
1ASTM D 512
D 7988
Total chlorine as chlorides
(maximum, mg/kg)
2ASTM D 4929
Gum, unwashed
(maximum, mg/100 mL)
20ASTM D 381
Gum, solvent-washed
(maximum, mg/100 mL)
5.0ASTM D 381
(maximum, mg/100 mL)
0.07ASTM D 1688
AppearanceProduct shall be visibly free of suspended or precipitated contaminants (shall be clear and bright).Appearance determined at ambient temperature or 21�C (70�F), whichever is higher.

N/A = Not applicable

Benefits of ethanol E85 fuels

This information can be utilized to understand the benefits of E85 ethanol fuel to see why ethanol fuel has great potential for large scale applications.

  • E85 is easy to use and handle – E85 fueling equipment is slightly different and of similar cost to equipment used to store and dispense petroleum fuels. In some cases, it may be possible to convert your existing petroleum equipment to handle E85.
  • Ethanol supports our America’s farmers – With the nation’s farmers begining to sell their land to home developers, their land will once again become valuable for growing the corn necessary for ethanol prodcution and will preserve America’s Heart Land.
  • Using E85 reduces petroleum consumption – Use of E85 will reduce a fleet’s overall use of petroleum and replace it with a renewable-based fuel produced ("grown") in the United States.
  • E85 is good for the environment
    – Beyond operational ease, E85 offers considerable environmental benefits. To learn more about fuel economy, greenhouse gas scores, and air pollution scores for individual vehicles, go to the U.S. Department of Energy/U.S. Environmental Protection Agency’s on-line Fuel Economy Guide. You can search for E85-fueled vehicles
    by selecting "flexible-fueled vehicles" in the "Select Vehicle Type" pull-down menu. Once you are there, select individual vehicles to get fuel economy, greenhouse gas, and air pollution details.
  • Reduced ozone-forming and overall toxic tailpipe emissions
  • Reduced fuel lifecycle greenhouse gas emissions (carbon dioxide)
  • It is primarily composed of ethyl alcohol (ethanol), derived from renewable resources
  • Ethanol is biodegradable and much less of a spill threat to surface and ground water than petroleum-based fuel spills.
  • Flexible Fuel Vehicles (FFVs) are available and affordable
    – FFVs specifically designed to run on E85 are becoming more common each model year, and FFVs are typically available as standard equipment with little or no incremental cost. See the current model year FFVs.
  • FFVs have flexible fueling options
    – FFVs may operate on gasoline, and, in fact, most of the 4 million FFVs on US roadways do today. Although that is not a positive from an E85-use standpoint, it does underscore the flexibility FFVs offer fleets. When E85 is not available, or an FFV travels outside the fueling network, a driver may simply fuel with either fuel as the situation dictates.