Federal investigators this month will release preliminary findings from a probe into the deadly 2010 Deepwater Horizon oil spill that may be more extensive than previous government reports and could directly point the finger at regulatory shortcomings.

The U.S. Chemical Safety and Hazard Investigation Board, or CSB, said earlier this week that it plans to hold two hearings July 23-24 in Houston to roll out the early findings and hear more testimony from experts.

CSB's investigation is the last of several government findings to be released, and there is speculation that it may be more revealing than others because of CSB's status as an independent agency charged with studying fatal chemical accidents and providing recommendations of what the government can improve.

The agency's chairman, Rafael Moure-Eraso, said earlier this year that the investigation will represent "an opportunity to make fundamental safety improvements to offshore oil and gas exploration to prevent future catastrophic accidents" (Greenwire, April 20).

CSB is planning for the first day of hearings to focus on downstream refining and the petrochemical sector, featuring a presentation from the American Petroleum Institute on an industry safety standard that was developed following the BP Texas City refinery fire that killed 15 workers.

The agency will then release preliminary findings on the second day, which will feature testimony from representatives of Norway, the United Kingdom and Australia.

"CSB's public hearing will provide a unique opportunity for safety experts from around the world to share information and discuss the most advanced work in the area of safety performance indicators for major accident prevention in high-hazard industries," Moure-Eraso said this week.

The House Energy and Commerce Committee asked CSB in 2010 to investigate the Deepwater Horizon spill. The agency has since reviewed "tens of thousands of documents from over 15 companies and parties in order to examine the use of safety indicators."

In an interview with Greenwire last year, Moure-Eraso said CSB is looking into why the United States does not require a "safety case" hazard system for offshore drilling operations. Such a system is required for most international drillers, and it mandates that companies submit documents on potential hazards and safety measures put in place to address them -- including accident response protocols (Greenwire, Sept. 29, 2011).

CSB is also looking into whether worker fatigue may have played a role, noting earlier this year that Transocean Ltd.'s workers had changed from 14-day shifts to 21-day shifts on board the rig before the accident.

The agency's investigation, however, has run into some roadblocks. CSB said Transocean wasn't cooperating with the probe, and Transocean -- while denying that charge -- questioned CSB's jurisdiction over the matter. The Department of Justice eventually sued Transocean for not complying with CSB's subpoenas.