Agilent Technologies has agreed to pay Sonoma County $120,000 to settle a case stemming from a chemical explosion that severely injured an employee at the company's Santa Rosa campus in April 2011, the District Attorney's Office announced Tuesday.

Agilent failed to report two smaller explosions in 2010, the District Attorney's Office said. As part of the settlement, the company is required to change the way it reports hazardous materials incidents.

"It is imperative that first responders have adequate information about workplace hazardous materials releases so that they may safely respond," District Attorney Jill Ravitch said in a news release. "Businesses should know that the law requires businesses to report the release or threatened release of a hazardous material that could present a danger to either employees or first responders."

The Santa Rosa Fire Department headed the investigation that revealed Agilent was not complying with mandated reporting requirements under the state Health and Safety Code that would inform first responders of releases of hazardous materials.

In the 2011 explosion, Patrick Colbus, now 48, suffered major burns when the machine he was working on exploded, shooting glass and several hazardous substances into his face and upper torso.

The Santa Rosa resident and Sonoma State University graduate was cleaning a molecular beam epitaxy machine, which produces thin coatings on integrated circuits.

Colbus was not wearing the required protective equipment and clothing at the time of the explosion, which released hazardous substances including phosphorous, arsenic and lead, according to the state Division of Occupational Safety and Health.

More than 20 workers underwent decontamination after complaining of respiratory problems after the explosion, which spewed smoke with a chemical odor.

Agilent paid $40,000 in fines to state regulators.

The company already has changed the way it reports hazardous materials incidents and has scheduled a training to inform employees of the policy, Agilent spokesman Jeff Weber said. He said the company thought it did not need to report the two 2010 explosions.

"We do acknowledge that there were two prior incidents," Weber said. "We mistakenly believed we were not required to report those incidents."

Weber declined to comment on any potential pending or future litigation from the incident, citing company policy.

Colbus remains an employee on "inactive status," Weber said.

"The injured employee is receiving disability payments and other income replacement benefits," he said.

He declined to comment on Colbus' condition citing the employee's privacy.

You can reach Staff Writer Matt Brown at 521-5206 or