Benzene is a chemical compound that occurs in small quantities naturally when it is emitted from forest fires, volcanic eruptions, and other organic processes. But the substance is also produced and used in a multitude of industrial applications and in concentrations that can – and often do – prove to be deadly for workers.
Benzene was first discovered and isolated from coal tar in the 1800s. Today, benzene is mostly a derivative of crude oil refining, hydraulic fracturing, and other processes in the petroleum industry. Once isolated, the chemical is provided in its liquid form to manufacturers across the world, who use it to synthesize chemicals or make plastics, rubber, dyes, detergents, explosives, pesticides, and a spectrum of other products, even pharmaceuticals. In fact, benzene is the 17th most widely produced chemical in the U.S. and one of the most commonly used.
Despite its many uses, benzene is also extremely toxic to the environment and harmful to human health. Liquid benzene is a highly flammable, colorless-to-pale-yellow liquid that evaporates rapidly when exposed to air. Releases of benzene vapor can accumulate in poorly ventilated workspaces and become explosive. Even in well-ventilated areas, benzene exposure can sicken exposed workers, either in the short term or over the course of several years.
Benzene Exposure and Toxicity
According to the Agency for Toxic Substances and Disease Registry (ATSDR), benzene’s sweet aromatic odor becomes detectable at concentrations of 60 parts per million parts in air and generally provides adequate warning of hazardous levels for acute exposure.
However, by the time a worker recognizes the smell of benzene, usually at concentrations of 100 ppm, he or she has already been exposed to a level of benzene several times the general maximum level of 1 part per billion and will likely start to feel the effects of short-term exposure, such as drowsiness, dizziness, headaches, tremors, confusion, and loss of unconsciousness. Due to these dangers, the U.S. Occupational Safety and Health Administration (OSHA) sets a short-term airborne benzene exposure limit of five ppm for any 15-minute period.
Benzene exposure over the long term, even in lesser concentrations, is particularly dangerous for U.S. workers. Exposure to benzene over several months or years can lead to anemia and other blood disorders. Long-term benzene exposure causes anemia and acute myeloid leukemia (AML) and may also lead to acute and chronic lymphocytic leukemia, non-Hodgkin’s lymphoma, and multiple myeloma. Such cancers are higher than normal among workers in certain industries, such as chemical manufacturing, shoemaking, ship-building, oil refining, and coal distillation. The maximum exposure limit for U.S. workers over the long term is just 1 ppm for an eight-hour workday.
According to the latest research, there is an association with leukemia at a chronic exposure level of 10 ppm or lower. A worker exposed to 10 ppm of benzene for 40 years is 155 times more likely to die from leukemia than an unexposed worker.
In “An American Tragedy,” a report looking at the deadly effects of benzene exposure on U.S. workers, the Center for Public Integrity says that a mounting number of lawsuits filed by sickened workers and their families over the past decade has “uncovered tens of thousands of pages of previously secret documents detailing the petrochemical industry’s campaign to undercut” the science linking benzene to leukemia and other cancers.
“Taken together, the documents … depict a ‘research strategy’ built on dubious motives, close corporate oversight and painstaking public relations,” the Center for Public Integrity explains. “They comprise an industry playbook to counteract growing evidence of benzene’s toxic effects, which continue to command the attention of federal and state regulators and be fiercely debated in court.”
Among the recently uncovered documents is an alarming study financed by five major petrochemical companies — British Petroleum, Chevron, ConocoPhillips, ExxonMobil and Shell Chemical — and the American Petroleum Institute (API) to examine benzene research in Shanghai, China, where benzene pollution continues to exist at dangerously high levels.
But rather than an objective inquiry, the $36-million “study” attempts to counter research “tying benzene to more types of cancer and at lower exposure levels than previously known,” according to the Center for Public Integrity. “They show how company executives and scientists plotted objectives and ‘expected’ results before the study began, banking on conclusions that would play down health hazards.”
This dubious research, which represents just one part of what resembles a massive industry coverup, means that more than five million U.S. workers continue to be exposed to benzene levels that could be slowly destroying their health.
Workers who are exposed to benzene at a concentration at or above 0.5 ppm over the course of eight-hour workdays or at or above 10 ppm in the past, have rights to information from their employer as well as a medical evaluation. Workers who are accidentally exposed to benzene on the job, either by ingestion, inhalation, or skin/eye contact, have a right to view employer documents, such as special laboratory tests concerning benzene. OSHA also guarantees workers several other rights when it comes to benzene exposure, including the right by you or your designated representative to observe benzene monitoring procedures and to record the results.
Centers for Disease Control and Prevention
Agency for Toxic Substances & Disease Registry
World Health Organization
The Center for Public Integrity
Environmental Protection Agency
The Daily Nonpareil
Los Angeles Times