Chemical of the Month – Benzene

Published 3:24 pm Saturday, September 24, 2022

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The area known as Cancer Alley was once home to thriving, rural Black communities, with fertile land nourished by the Mississippi River. But petrochemical development that began in the 1960s has poisoned the air, water, and life in the area. Trees fell; crops withered; flowers died. Few households today are untouched by cancer, asthma, or premature birth.

But today, the water in these communities is not safe to drink, the air is choked with foul smells, and the soil no longer yields healthy crops. One chemical which may have contributed to this great dying is benzene. Benzene prevents plants from completing the photosynthesis process. It chokes plant respiration by replacing the carbon dioxide that plants breathe. And animal studies show low birth weights and bone marrow damage in infants exposed to airborne benzene during pregnancy.

While new laws and technologies have prevented many benzene-related deaths, certain workers and residents of industrialized neighborhoods are regularly exposed to dangerous levels of benzene. Louisiana has the highest rate (per land area) of industrial benzene emissions in the United States. These emissions (also called air pollution) are highest overall in Calcasieu Parish, followed by the “Cancer Alley” parishes, including St. James and St. John the Baptist. While benzene is less potent than some other cancer-causing chemicals like ethylene oxide, it is far more common. The result is that benzene and ethylene oxide contribute to a significant chunk of the pollution-related cancer risk for most residents of southeast Louisiana.

The EPA recognizes benzene as a human carcinogen, and the U.S. Agency for Toxic Substances Disease Registry (ATSDR) establishes the acute level of harm, or the level at which short-term exposure to benzene can cause health effects, as 29 micrograms per cubic meter of air. But for the two week period from August 24-September 7, 2021, the benzene concentration at Valero’s New Orleans Refinery in Norco was 10 times higher than ATSDR’s harmful level. Even though the EPA requires refineries to conduct fenceline monitoring for benzene, refineries and other petrochemical facilities regularly violate safe levels. These facilities are not required to release their air monitoring data to the public. If industry and LDEQ won’t help protect us from hazardous air pollution, or even let us know what is already in the air, then we need community powered air monitoring to fill this gap.

In humans, long-term exposure, even if below the “safe level” of benzene- such as working at a plant that emits it, or living or going to school nearby- is linked to leukemia. Benzene is metabolized in the liver, lungs and bone marrow; exposure, even during a single release event, can cause liver damage that later presents a cancer risk. Short-term exposure to benzene can cause headaches, dizziness, and irritation to the eyes, skin, and respiratory tract, as well as damage to the immune and blood systems. Long-term exposure can lead to blood disorders and increase the risk of leukemia. Benzene is also found in cigarette smoke and gasoline-powered car emissions.

Benzene already poses a danger to Louisiana communities. In 1997, a barge spilled up to 400,000 gallons of benzene into the Mississippi River, which required the evacuation of the entire Southern University campus. Exxon Mobile’s three Baton Rouge plants have been a frequent source of rogue benzene emissions, including a 2020 fire, a 2017 settlement that addressed years of unsafe discharge, and a 2012 leak of over 31,000 pounds which caused widespread harm to plant workers and fenceline community members. Since benzene exposure can cause harm years later, the effects of these releases are not short-term. Many towns and parishes currently lack the infrastructure to properly warn and evacuate residents from existing dangers- so adding in more hazardous benzene production is adding fire to an already boiling pot. We already have a benzene problem in Louisiana, and there’s no need for more.

Last week, a Louisiana judge canceled Formosa Plastics’ air permit, in part because of the health risks related to its emissions of benzene and other carcinogens. This decision was celebrated by residents and community advocates in St. James Parish, where the massive petrochemical plant would have been built. The permit would have allowed Formosa Plastics to emit more than 35 tons per year of benzene – making it one of the highest emitters of benzene in Louisiana. Because any exposure to a cancer-causing chemical increases a person’s cancer risk, we can say with 100% certainty that the judge’s decision lowered the risk of blood cancer for everyone who would have been exposed to Formosa Plastics’ benzene emissions.

We’ve all heard the argument that these chemical plants bring jobs. No one deserves the false choice of a chemical plant job that poses a serious risk to their health. A worker exposed at 10 ppm of benzene for 40 years- which is normal exposure for a plant worker- is 155 times more likely to die from leukemia than an unexposed worker. A job with benzene exposure at Formosa Plastics would not have been a long-term career- simply because its workers may not have long to keep living.



  • Benzene is used to make chemical detergents. Switch over to plant-based detergents, like Dr. Bronner’s or 7th Generation.
  • Synthetic clothing dyes derived from benzene are extremely toxic, and the workers in countries like Bangladesh, Vietnam, and India who handle them develop chemical burns, lung damage and cancer. When buying new clothes, search online for producers using naturally dyed fabrics.
  • Many pesticides are derived from benzene, but USDA Organic food is produced without such pesticides. Ask your local farmers at the farmer’s market if they are currently spraying their food crops with pesticides, and which kind. There are lots of small farms out there which are “no spray”, even if they do not meet all of the costly requirements to be certified organic.


The Community Scientists’ Chemical of the Month is a service program of RISE St. James; Caitlion O. Hunter, Juris Doctor, Class of 2022, past president, Loyola Environmental Law Society; Tim Schütz, PhD sesearcher, Anthropology University of California, Irvine; and The Community Scientist (TCS) Research Team.