A truck traveling through Phoenix leaked more than 110 gallons of hydrofluorosilic acid on Friday, closing a significant part of downtown and keeping residents inside.
Sixteen people – the truck’s driver, 11 police officers and four civilians – were taken to hospitals for evaluation because they may have stepped into the liquid. Three firefighters also were evaluated for possible exposure.
The acid can cause injuries similar to burns, but only if it is touched, officials said. The chemical was not considered an inhalation hazard in the form it was in.
“We don’t want to overalarm people,” said Assistant Phoenix Fire Chief Bob Khan. “You’ve got to go through it. . . . It’s kind of like a mud puddle. If you walk through it, you get mud on you.”
The spill was discovered shortly after 10 a.m. As a precaution, authorities activated the reverse-911 system, notifying 9,554 people in nearby areas to “shelter in place” – which means to stay inside if possible. Fifth to Seventh avenues from Monroe to Grant streets were closed downtown. Seventh Avenue was reopened Friday evening.
The truck apparently began leaking at Seventh Avenue and Grant, Khan said. The driver then noticed the leak and pulled over at Fifth Avenue and Monroe. Streets along his route with elevated acid readings were power-washed.
The trucking firm, LA Chemical Co. in Las Vegas, has a satisfactory rating with the U.S. Department of Transportation. Records show the company, which ships liquids, gases and chemicals interstate, passed a hazardous-materials inspection within the past 24 months. Its trucks haven’t been involved in any fatal or injury crashes in the past two years.
Hydrofluorosilic acid is an industrial byproduct used in the fluoridation of water and in dry cleaning. Trace amounts of arsenic and lead usually are found with it.
Friday’s incident was yet another nuisance for Phoenix residents, like Jimmy Matthews, 66, who last week were boiling water after problems emerged at the city’s Val Vista water treatment plant.
“I saw all these police officers, and I knew something was going on,” said Matthews, who lives at the nearby Westward Ho. “It’s like one thing happening after another.”