SAN FRANCISCO — Corrosion that went unchecked – the suspected cause of a fire at Chevron Corp.'s Richmond refinery in August – has been linked to a fire at the plant in October 2011, the San Francisco Chronicle reported Sunday (). http://bit.ly/OzFQcu

According to state inspection documents obtained by The Chronicle, a state Division of Occupational Safety and Health inspector who investigated the smaller 2011 fire documented allegations from two workers of corrosion at the refinery.

The 2011 fire took place during a scheduled maintenance shutdown and was quickly extinguished.

"We're afraid something is going to fall through the cracks," one worker told Cal/OSHA safety inspector Carla Fritz, who went to the plant to investigate the fire last November.

"We're concerned about increased corrosion – we've increased temperatures and increased rates, and it takes a toll on the equipment," said the worker, who was identified in Fritz's notes as head operator of the lube oil plant – the most senior of a 20-member operator crew.

Cal/OSHA said in a statement that a violation notice was not issued to Chevron over the 2011 fire "because the problem alleged and potential hazard had been already identified and corrected."

The Chronicle obtained Fritz's notes under the state Public Records Act. State officials redacted the names of Chevron employees she interviewed.

A Chevron spokesman told the Associated Press that the 2011 fire was contained in a furnace in the lubricants plant, and that the company took appropriate actions afterward to protect the safety of its employees and facilities.

"We immediately responded, shut down the affected operations, evacuated all non-essential staff, and successfully contained the incident," Sean Comey said in a statement.

He added that workers at Chevron have the authority to stop any operation, without any repercussions, if they believe people or the environment are in danger.

Another fire struck the refinery on Aug. 6, creating a huge plume of black smoke and sending thousands of people to hospitals with health complaints.

Chevron later said it was stepping up inspections after it was determined that the blaze was caused by a failure in a five-foot section of an old pipe.

Earlier on HuffPost:

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  • Chevron refinery over Point Richmond.

    <a href="http://www.huffingtonpost.com/social/NoahC"><img style="float:left;padding-right:6px !important;" src="http://s.huffpost.com/images/profile/user_placeholder.gif" /></a><a href="http://www.huffingtonpost.com/social/NoahC">NoahC</a>:<br />

  • Smoke obscuring the sun

    <a href="http://www.huffingtonpost.com/social/VOOOLN"><img style="float:left;padding-right:6px !important;" src="http://images.huffingtonpost.com/twitter_profile_img/3704700.png" /></a><a href="http://www.huffingtonpost.com/social/VOOOLN">VOOOLN</a>:<br />Taken at 7pm in Richmond, two miles from the Chevron refinery.

  • Chevron refinery from Point Richmond.

    <a href="http://www.huffingtonpost.com/social/NoahC"><img style="float:left;padding-right:6px !important;" src="http://s.huffpost.com/images/profile/user_placeholder.gif" /></a><a href="http://www.huffingtonpost.com/social/NoahC">NoahC</a>:<br />

  • Chevron refinery from Point Richmond living room.

    <a href="http://www.huffingtonpost.com/social/NoahC"><img style="float:left;padding-right:6px !important;" src="http://s.huffpost.com/images/profile/user_placeholder.gif" /></a><a href="http://www.huffingtonpost.com/social/NoahC">NoahC</a>:<br />

  • Chevron refinery explosion captured as it happened

    <a href="http://www.huffingtonpost.com/social/DrewDell"><img style="float:left;padding-right:6px !important;" src="http://i.huffpost.com/profiles/460318-tiny.png?20091110142242" /></a><a href="http://www.huffingtonpost.com/social/DrewDell">DrewDell</a>:<br />Photo: Drew Dellinger

  • Chevron refinery explosion captured as it happened

    <a href="http://www.huffingtonpost.com/social/DrewDell"><img style="float:left;padding-right:6px !important;" src="http://i.huffpost.com/profiles/460318-tiny.png?20091110142242" /></a><a href="http://www.huffingtonpost.com/social/DrewDell">DrewDell</a>:<br />Photo: Drew Dellinger

  • Chevron Oil REfinery FIre

    <a href="http://www.huffingtonpost.com/social/jrdenkin"><img style="float:left;padding-right:6px !important;" src="http://images.huffingtonpost.com/aol_profile_img/3705541.png" /></a><a href="http://www.huffingtonpost.com/social/jrdenkin">jrdenkin</a>:<br />

  • Chevron explodes

    <a href="http://www.huffingtonpost.com/social/MichaelJ2006"><img style="float:left;padding-right:6px !important;" src="http://s.huffpost.com/images/profile/user_placeholder.gif" /></a><a href="http://www.huffingtonpost.com/social/MichaelJ2006">MichaelJ2006</a>:<br />Looking west from Richmond CA.

  • Chevron refinery fire 1

    <a href="http://www.huffingtonpost.com/social/cwishard"><img style="float:left;padding-right:6px !important;" src="http://s.huffpost.com/images/profile/user_placeholder.gif" /></a><a href="http://www.huffingtonpost.com/social/cwishard">cwishard</a>:<br />Taken from the richmond bridge at 6:35 pm.

  • First plume of smoke.

    <a href="http://www.huffingtonpost.com/social/cwishard"><img style="float:left;padding-right:6px !important;" src="http://s.huffpost.com/images/profile/user_placeholder.gif" /></a><a href="http://www.huffingtonpost.com/social/cwishard">cwishard</a>:<br />First sign of trouble on the richmond bridge, 6:35 pm

  • plume

    <a href="http://www.huffingtonpost.com/social/merigorownd"><img style="float:left;padding-right:6px !important;" src="http://s.huffpost.com/images/profile/user_placeholder.gif" /></a><a href="http://www.huffingtonpost.com/social/merigorownd">merigorownd</a>:<br />Plume of smoke over my house from the Chevron Refinery fire.

  • Chevron Refinery Fire

    <a href="http://www.huffingtonpost.com/social/merigorownd"><img style="float:left;padding-right:6px !important;" src="http://s.huffpost.com/images/profile/user_placeholder.gif" /></a><a href="http://www.huffingtonpost.com/social/merigorownd">merigorownd</a>:<br />Chevron Refinery Fire from a tower behind the plant

  • Chevron Refinery Fire

    <a href="http://www.huffingtonpost.com/social/merigorownd"><img style="float:left;padding-right:6px !important;" src="http://s.huffpost.com/images/profile/user_placeholder.gif" /></a><a href="http://www.huffingtonpost.com/social/merigorownd">merigorownd</a>:<br />Chevron Refinery Fire from a tower behind the plant. (Photo: Mimi Vitetta)

  • Chevron Refinery Fire

    <a href="http://www.huffingtonpost.com/social/merigorownd"><img style="float:left;padding-right:6px !important;" src="http://s.huffpost.com/images/profile/user_placeholder.gif" /></a><a href="http://www.huffingtonpost.com/social/merigorownd">merigorownd</a>:<br />A view inside the neighborhood, the Iron Triangle. (Photo: Mimi Vitetta)

  • From Kensington

    <a href="http://www.huffingtonpost.com/social/rododu"><img style="float:left;padding-right:6px !important;" src="http://graph.facebook.com/1148340129/picture?type=square" /></a><a href="http://www.huffingtonpost.com/social/rododu">rododu</a>:<br />

  • Richmond Chevron fire from SF/Oakland ferry

    <a href="http://www.huffingtonpost.com/social/hailfromsf"><img style="float:left;padding-right:6px !important;" src="http://s.huffpost.com/images/profile/user_placeholder.gif" /></a><a href="http://www.huffingtonpost.com/social/hailfromsf">hailfromsf</a>:<br />Photo of Richmond Chevron refinery fire, taken minutes after black cloud formed, from the SF/Oakland ferry.

  • Chevron Oil Fire as seen from Mill Valley in Marin County

    <a href="http://www.huffingtonpost.com/social/prthatrocks"><img style="float:left;padding-right:6px !important;" src="http://graph.facebook.com/1074196206/picture?type=square" /></a><a href="http://www.huffingtonpost.com/social/prthatrocks">prthatrocks</a>:<br />Chevron Oil Fire as seen from Mill Valley in Marin County. Krista busts into the apartment and says, "What is going on with all that smoke?" As seen from our houseboat from the Commodore Marina next to the Seaplane Adventures dock in Mill Valley. The smoke is rising over Tiburon in the distance.

  • Chevron refinery fire.

    <a href="http://www.huffingtonpost.com/social/gjmurphy"><img style="float:left;padding-right:6px !important;" src="http://s.huffpost.com/images/profile/user_placeholder.gif" /></a><a href="http://www.huffingtonpost.com/social/gjmurphy">gjmurphy</a>:<br />Taken in Point Richmond, 8/6/12 at 7pm