By J. PATRICK PEPPER
DEARBORN — A toxic mixture of swimming pool chemicals caused an evacuation and cancellation of classes one day last week at Fordson High School.
Roughly 2,400 people were shuttled out of the building Wednesday shortly after classes began, when students and staff began complaining of a noxious odor. Dearborn Public Schools officials said the vapor was created when a maintenance employee combined muriatic acid and chlorine in the pool’s filtration system.
The pool is in the basement of the 1920s-built high school, and district officials said the vapors rose through ventilation shafts and stairwells into classrooms above.
Muriatic acid balances pH levels to make pool water comfortable to the human eye, while chlorine is used to neutralize organic materials in the water. Both chemicals are used regularly for pool cleaning, but are supposed to be added separately and at a measured pace, district officials said. When combined in high amounts they produce chlorine gas, which if inhaled can irritate mucous membranes, cause shortness of breath and — in high enough concentrations —even death.
“There’s two separate tanks, one that holds the muriatic acid, one that holds the chlorine,” explained district spokesman David Mustonen. “There is a mechanism that controls the amount of each chemical that’s mixed together with the water. What (the employee) did is they added chlorine into the wrong container, causing a chemical reaction.”
The worker who mixed the chemicals was overcome instantly by the fumes and taken to a local hospital for treatment, district officials said.
Another staff member also went to an area hospital to seek treatment after the incident. A Wayne County hazardous material crew was dispatched to the school, along with Dearborn public safety officers, to oversee the cleanup and dispersal, which took about four hours.
The school was reopened at 2 p.m. for extracurricular activities and teacher conferences that night.
Mustonen said preliminarily the district is considering the incident accidental, but will conduct an investigation to examine whether it was caused by negligence. He added that a regularly scheduled lockdown drill on Thursday also caused some disruption of classes.