Martinez Refinery Release: Lab Results Show No Ongoing Health Risk

MARTINEZ, CA — Samples of the coke dust released by Tuesday by Martinez Refining Company did not contain high levels of toxic metals, indicating the dust does not pose an increased, long-term risk to public health, Contra Costa Health Services said Friday.

CCH’s Hazardous Materials Program sent samples of the sooty substance for laboratory analysis after it accumulated on cars, garbage cans and other surfaces in neighborhoods around the refinery soon after notification of the release on July 11. Read the full laboratory report here.

MRC reported the release at about 10:20 a.m. Tuesday by activating the county’s Community Warning System at Level 1, the lowest-level alert, used for hazardous materials releases when there are no expected off-site health consequences.

MRC reported the material was coke dust, a black, sooty or powdery residue created during petroleum refining that primarily contains carbon and is chemically similar to charcoal. The material was released about 8:30 a.m. for approximately one minute, according to MRC.

• PREVIOUS COVERAGE: Refinery Releases Coke Dust, Delays Notification: County

CCH and the Bay Area Air Quality Management District are investigating the incident to determine whether the release violated regulatory law.

CCH is also investigating whether MRC properly followed the county’s emergency notification policy and properly used the Community Warning System, as required by law.

Coke dust can be safely washed off surfaces with soap and water. The primary health concern regarding the release of coke dust is irritation of the throat, lungs and respiratory system while the release was occurring and the material was in the air, particularly for people with respiratory conditions such as asthma, county health officials said.

Anyone who believes they have symptoms or health concerns due to breathing material released during the July 11 incident should contact their healthcare provider, the county said.

CCH expects to learn more about the contributing causes of the incident, actions immediately taken, and proposed actions to prevent a similar incident from happening again. The first incident report from MRC to CCH, required by the county’s notification policy, will be available Monday at cchealth.org.

Health Advisory Lifted In June

This week's release of coke dust came after a health advisory was lifted in June after soil samples were tested for any lingering toxicity from the November 2022 spent-catalyst discharge by Martinez Refining Company.

A mechanical failure four days before Thanksgiving started a chain of events leading to a Thanksgiving night discharge from the Martinez refinery. Initial samples of the dust showed elevated levels of aluminum, barium, chromium, nickel, vanadium, and zinc, all of which can cause respiratory problems.

MRC was criticized for not notifying the community or the county once the Thanksgiving night discharge started, as required by law. County health officials said they didn't hear of any problems until residents reported seeing dust on their cars the next day.

A health advisory in March warned refinery neighbors not to eat produce grown in soil possibly contaminated by spent catalyst dust until environmental testing was completed.

Soil samples were taken in May from more than a dozen sites exposed to a 20- to 24-ton plume of dust in an area that stretches from the refinery in Martinez into Benicia and parts of Hercules, Alhambra Valley, Franklin Canyon and El Sobrante. The assessment was done by the contractor TRC, which concluded metals detected in 14 soil samples didn't appear in similar ratios or quantities to spent-catalyst dust samples collected shortly after the release Nov. 24-25, 2022.

CCH said the primary health risk from the November 2022 release occurred during the initial hours and days after the refinery accident when people may have breathed in dust particles.

—Bay City News contributed to this report.