OSHA posts its inspection records online, and it's possible to search through them by business name. The Office of Pipeline Safety and the Minerals Management Service also post accident data online, but neither organizes the information by company. One could attempt to cobble together a holistic safety record by poring through all of the disparate agencies' inspections records, but that would still leave out global operations. Most big oil companies have production outfits all over the world.

    Nibarger says the American Petroleum Institute tracks incidents across different categories but that the information isn't public. API spokesman Bill Bush says the trade group only follows and publishes injury data.

    "All of the government agencies focus on their piece of the pie, and no one is likely to have the big picture," he says. "It would be nice if they did, but they don't."

    With such scattershot information, what can oil investors do to evaluate a company's safety performance? Not much, says Deutsche Bank's Sankey, who thinks the federal government should aggregate the data so there's an industry benchmark. Without such information, he says, there's no way of accounting for risk until it's already too late.