The Problem

Do You Know What’s in Your Gas? Because It’s Harming Your Health

It’s a problem that’s too small to see but too big to ignore. Every day, we breathe in harmful emissions produced by our vehicles. At least 25 percent of gasoline contains aromatic compounds, which are known and suspected carcinogens such as benzene, toluene, ethylbenzene, and xylenes (BTEX group). These aromatics are added to boost octane in gasoline and are being used as replacements for lead. Yet like lead, we know these aromatics are also extremely dangerous to our health. The EPA has even classified them as a hazardous air pollutant because they don’t fully combust and escape into the atmosphere hurting our health.

So Why Are They Allowed in Gasoline?

From our perspective, the EPA has primarily focused on emissions from diesel and coal plants, ignoring gasoline emissions, which are actually the most harmful. UAI has been ringing the alarm for years hoping that the mounting body of health-related evidence will compel the EPA to act. The EPA not only has the authority to regulate air toxics but is required to do so under the 1990 Clean Air Act. UAI is pushing for changes to be made through improved public policy and public education.

Choose an Issue Below to Learn More

Frequently Asked Questions

  • What are aromatics?

    Aromatic hydrocarbons already exist in crude oil sources, but are also added to gasoline during the oil refining process. Aromatics are used to increase octane. These are generally toxic and often carcinogenic substances that are regulated by the U.S. Environmental Protection Agency (EPA) as air toxics. These aromatics include benzene, toluene and xylene and are often referred to as the BTEX Group. However, there are many other aromatics that exist in the final gasoline blend.

  • Why are aromatics used in gasoline?

    One of the greatest successes of the 1970’s Clean Air Act was mandating the removal of lead – the predominant source for increasing octane in gasoline. Lead is a known poison and presented numerous health problems. Unfortunately, phasing out lead resulted in a new problem as refiners looked to boost octane and prevent engine knocking by using more aromatic compounds. Though these aromatic compounds are health hazards themselves, but still considered less toxic than lead.

  • What are the health issues associated with aromatics?

    Whether it’s spikes in low birth weights in Los Angeles or off-the chart asthma cases in Minneapolis, the patterns are consistent, and exposure to urban air and high levels of traffic pollution can have profound health effects. This is due to the fact that aromatics come out of our vehicles as ultra-fine particulates that bypass the lungs and directly enter the bloodstream. Ultra-fine particulates are not found in nature, they are only man-made. So, our body’s natural defenses can’t filter the threat of something that’s smaller than the width of a human hair.

    In March 2011, an EPA report estimated that reducing particulate matter (PM) according to Clean Air Act requirements would save nearly 230,000 people from early death in the year 2020 and save nearly $2 trillion in health-related expenses.

  • What percentage of my gasoline contains aromatics?

    Today’s gasoline contains, on average, 25 percent aromatic compounds. According to the U.S. Department of Energy, the current gasoline pool is estimated at 135 billion gallons sold annually.  With 25 percent being aromatic compounds, that means about 30 billion gallons of aromatics are used each year.

  • How much air pollution from aromatics is due to gasoline combustion?

    The EPA estimates that 85 percent of aromatic benzene and its derivatives in urban areas comes from motor vehicle exhaust. EPA calculations related to Mobile Source Air Toxics show reducing just 0.15 percent of particulates that are produced from these aromatics is worth $15 billion in health-related benefits.

  • Can ethanol be used as an octane substitute for aromatics?

    Yes, ethanol can provide a clean octane source to gasoline, reducing the need for aromatics. Ethanol offers twice the octane increase when simply added to gasoline compared to any other gasoline component, making it also the most economical choice. Right now most gasoline in the United States has 10% ethanol in it. That alone replaced 7.2 billion gallons of aromatics in 2017.

    To learn more about how ethanol works in different kinds of engines, visit Fueling the Truth.

  • Does Congress have to approve the replacement of aromatics with ethanol?

    No. More than 20 years ago, Congress acted by voting overwhelmingly for clean octane provisions in the Clean Air Act Amendments of 1990. The Clean Air Act clearly gives the EPA the statutory authority and legal obligation to reduce aromatic pollutants in motor vehicle exhaust.

  • Is there enough ethanol to replace significant levels of aromatics?

    Yes. The ethanol industry produced more than 15 billion gallons in 2017, which means a growing and stable ethanol supply can meet more of the octane needs of petroleum refiners.