You Ask: Patch Answers Questions About the Chevron Refinery Fire

This week, we asked readers what they still had about the Chevron refinery fire. wanted to know more about the acrolein the Bay Area Air Quality Management District reported in an update after first declaring that the fire did not produce dangerously high levels of toxins. 

We're still working on the other questions. 

What was the concentration of acrolein measured by the BAAQMD?
The air sample that prompted an update from the Bay Area Air Quality Management District contained 3.23 parts per billion (ppb) of arcolein.

When and where was the measurement taken?
The sample was taken on the night of the fire at 8:05 at the corner of Arlington Boulevard and Potrero Avenue in El Cerrito, so it was downwind from the fire at the refinery in Richmond.  A second sample measured about 25 minutes later and seven blocks away showed arcolein levels of .19 parts per billion.

At what concentration is acrolein considered dangerous?
Acrolein is a byproduct of burning gas and oil and is also produced by burning wood, animal fat and tobacco.

The California Office of Environmental Health Hazard Assessment determined that the acute Reference Exposure Level of acrolein is 1.1 ppb.

According to Lisa Fasano of BAAQMD, reference exposure levels are not standards but rather a measurement of pollutants that could trigger a health issue in the most vulnerable populations.  “It will be protective of everybody in the community regardless of age, size, health condition, chronic conditions,” said Fasano.  “At this level or below, nobody should see any health effects.”

On any given day the normal background level of acrolein in the Bay Area is between 1 ppb and 4.5 ppb, and levels as high as 16 ppb have been detected in other parts of the state, according to the BAAQMD.

See all of Patch's Chevron refinery fire coverage.