Mounting evidence against benzene

  • First case

    The first case of benzene-induced leukemia is reported.

  • Only safe concentration is zero

    The American Petroleum Institute concludes that “the only absolutely safe concentration for benzene is zero.”

  • Goodyear study

    The National Institute for Occupational Safety and Health launches a study of two Goodyear plants in Ohio where workers are exposed to benzene at high levels — 10 parts per million to 100 ppm. Responding to the study, the Occupational Safety and Health Administration issues an emergency temporary standard for benzene of 1 ppm, down from 10 ppm.

  • Final standard

    OSHA issues its final benzene standard of 1 ppm, sparking a legal challenge from API that lasts nearly a decade and goes to the U.S. Supreme Court.

  • Ohio results

    NIOSH researchers examining the two Ohio plants establish that the exposures increased five-fold the workers’ risk of developing leukemia.

  • Benzene Task Force

    The API’s Benzene Task Force kicks off an industry campaign to counter the Ohio study. The oil lobby acknowledges that “high doses of benzene can cause some forms of cancer,” but not necessarily “low concentrations.”

  • National Cancer Institute study

    A National Cancer Institute study of benzene-exposed workers in Shanghai, China, appears on the petrochemical industry’s radar.

  • National Cancer Institute study

    The first NCI paper reports significantly elevated risks of leukemia, myelodysplastic syndrome and non-Hodgkins lymphoma at levels of benzene exposure around the OSHA limit of 1 ppm.

  • A new Shanghai study

    The Benzene Task Force outlines the strategy for the industry’s own Shanghai study as well as other benzene research efforts “designed to protect member company interests…” Documents paint the research as a counterweight to the NCI study.

  • "Benefits" to bottom lines

    BP, Chevron, ExxonMobil, ConocoPhillips and Shell Chemical sign an agreement with the task force and API launching what will become the Benzene Health Research Consortium to fund what’s expected to be a five-year study costing approximately $20 million.

  • Project unveiled

    The Shanghai study is publicly unveiled at China’s Fudan University, home to the project’s multi-million-dollar, state-of-the-art laboratory.

  • No safe exposure

    The NCI releases its second major study of benzene-exposed Chinese workers. It shows that workers who inhaled less than 1 ppm of benzene had fewer white blood cells than unexposed workers, strongly suggesting there is no safe exposure threshold for the chemical.

  • Shanghai costs soar

    Shanghai project expenses soar to more than $26 million.

  • Benzene regulations launched

    The EPA launches what some experts consider its most substantive effort to regulate benzene in years — a rule requiring the reformulation of fuel to reduce benzene content. “Benzene is the most significant contributor to cancer risk from all outdoor air toxics,” EPA officials state.

  • "Risk management"

    An API memo details the lobby group’s benzene “risk management” program, which aims to “develop scientific data . . . for use in science advocacy, risk management, litigation support.” The memo states that benzene is “of particular concern to the industry” because “tighter regulation . . . could impose substantial costs.”

  • Shangai project ends

    The Shanghai project officially ends, though articles about the research will continue to appear in scientific journals and be used by industry to defend lawsuits by U.S. workers exposed to benzene.

  • Continued impact

    As of October, 30 papers have been published with consortium funds; in general, the Shanghai study has found that only certain subtypes of acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS) show statistically significant associations with the chemical. It also has shown “a possible association” between benzene and a subtype of non-Hodgkins lymphoma — a controversial finding that some industry scientists dispute.