Fossil Fuel Companies Distorted the Science about the Dangers of Benzene

Benzene is a colorless, sweet-smelling liquid that ranks among the 20 most widely used chemicals in the United States. Present in crude oil, gasoline, and cigarette smoke, benzene was once commonly used as an industrial solvent and gasoline additive but is now mainly used as a starter material for other chemicals. The Environmental Protection Agency, the National Toxicology Program, and International Agency for Research on Cancer all classify benzene as a known human carcinogen.  

Petrochemical companies have long been aware of the dangers posed by benzene. In 1948, a toxicological review prepared for the American Petroleum Institute (API), the oil and gas industry trade group, stated: “it is generally considered that the only absolutely safe concentration of benzene is zero.” Two years later, a memorandum to Shell Development Company noted that benzene was one of only “relatively few instances” in which “the origin of environmental cancer can be traced to contact with well-defined chemical agents possessing established carcinogenic qualities.”

Yet despite the fact that petrochemical companies knew for as long as 70 years that benzene was dangerous—even lethal—for workers at their facilities, that knowledge was not enough to deter major companies’ executive and legal teams from pouring millions of dollars into industry-shaped science “designed to protect member company interests” that downplayed the link between benzene and disease.

In 1997, the National Cancer Institute (NCI) published a major study of Chinese workers suggesting that benzene’s dangers went beyond acute myeloid leukemia (AML), the cancer most closely linked to benzene exposure. The authors concluded, “the results of the study suggest that benzene exposure is associated with a spectrum of hematologic neoplasms and related disorders in humans.” In other words, benzene exposures at even low limits could trigger diseases other than leukemia, in particular non-Hodgkin’s lymphoma and myelodysplastic syndromes (MDS).

The idea that benzene could be tied to multiple types of cancer was of grave concern to petrochemical companies—not necessarily because of worker safety, but because of potentially expensive reforms the companies would have to make to prevent exposure to benzene. As a series of documents obtained and analyzed by the Center for Public Integrity reveal, the major petrochemical companies—BP, Chevron, ConocoPhillips, ExxonMobil, and Shell Chemical—all worked through API to plan and fund $36 million worth of scientific research on benzene exposure intended to bring “tremendous economic benefit to the petroleum industry” by reducing “onerous regulations” and “litigation costs.”

API’s proposal explicitly noted that the research project, to take place in Shanghai, would be designed as a direct response to the 1997 NCI study. Even before the Shanghai study began, API had identified expected outcomes for the research. In its proposal, API wrote that “the planned research is expected to…provide strong scientific support for the lack of a risk of leukemia or other hematological disease at current ambient benzene concentrations to the general population,” to “establish that adherence to current occupational exposure limits…do not create a significant risk to workers exposed to benzene,” and to “refute the allegation that Non-Hodgkin’s lymphoma can be induced by benzene exposure.”

Many of the industry-funded scientists involved dispute the allegation that the science was a sham. But the 30 scientific papers deriving from the Shanghai research project found comparatively limited links between benzene and disease, and the industry has used these papers to defend itself in multiple lawsuits.