Bloated and bed-ridden, his skin browned by blood transfusions, John Thompson succumbed to leukemia on November 11, 2009.

A carpenter by trade, Thompson, then 70, had spent much of his life building infrastructure for the petrochemical industry in his native Texas — synthetic rubber plants in Port Neches, chemical facilities in Orange. Throughout the 1960s and early 1970s, he often encountered benzene, stored on job sites in 55-gallon drums, which he used as a cleaning solvent. He dipped hammers and cutters into buckets full of the sweet-smelling liquid; to expunge tar, he soaked gloves and boots in it.

Thompson never figured the chemical could do him harm. Not when it stung his hands or turned his skin chalky white. Not even when it made him faint. But after being diagnosed with a rare form of leukemia in 2006, relatives say, he came to believe his exposure to benzene had amounted to a death sentence. Oil and chemical companies knew about the hazard, Thompson felt, but said nothing to him and countless other workers.

“They put poison on his skin and in the air he breathed,” said Chase Bowers, Thompson’s nephew. “He died because of it.”