Nitric Acid Spill in Arizona

A couple of news reports (here and here) about a truck rollover accident on I-10 in Arizona yesterday feature a release of fuming nitric acid. The Fox News report includes a video of cars driving through the orangish cloud of nitric acid fumes. Both articles note that the driver was killed in the accident, not sure if it was from the physical effects of the rollover or from chemical exposure.

While a section of I-10 is closed for cleanup of the mess, the CNN article downplay the hazards of nitric acid exposure, noting that the CDC reports that exposure “to it can cause irritation to the eyes, skin and mucous membrane.” The Fox article is less cavalier noting that “it can cause delayed pulmonary edema, pneumonitis, bronchitis, dental erosion, and irritation to the eyes, skin and mucous membrane”.

The short term exposure limit (STL) for nitric acid fumes is 4 ppm, but ‘short term’ is set by OSHA at 15-minutes, so folks driving through the cloud probably (a nasty word to be used in a chemical incident) would not be affected. It could be a different story for anyone with respiratory problems. As a general life rule, I tend to avoid chemical clouds without appropriate PPE.

Since this is a transportation related incident, it is not a CSB reportable accident. Any federal investigation of the incident would be conducted by the National Transportation Safety Board.