SEMINOLE — It started as a simple chemistry assignment.
Students were to bring to class an item representing an element of the periodic table. Some brought aluminum foil, salt and water.
But some brought sodium, lithium and even mercury.
As a precaution, a teacher called the principal, who called authorities.
Within minutes, fully equipped hazmat investigators and firefighters bore down on the building. School officials rummaged through the bookbags and lockers of the 125 students assigned the project.
Some 2,200 students were locked down in first-period classes.
"It's almost stupid," said sophomore Kyle Salvaggio.
In the end, about 10 projects — "anything that could potentially be dangerous" — were taken from students, said Pinellas Schools spokeswoman Melanie Marquez.
The mercury came in thermometers, Marquez said, but it was unclear what the lithium and sodium were brought in.
She said calling authorities was a cautious reaction.
The incident will be reviewed by school principal Walter Weller, who did not return a call for comment.
School officials also declined to disclose the chemistry teacher's name.
Weller called authorities, Marquez said, because he wanted to make sure none of the items were hazardous and to avoid any spills that could expose students. Exposure to mercury can cause renal and neurological problems.
Seminole Fire Rescue and some of their hazmat personnel arrived at the school at 8401 131st St. N about 8 a.m. Investigators from the Pinellas County Hazardous Materials Response Team also responded.
Investigators talked to school officials and determined there were no spills or exposure to hazardous materials, said Seminole Fire Rescue Division Chief of Training Thomas Winkler.
A Pinellas Schools employee retrieved the potentially hazardous projects, Marquez said.
HazMat officials left within 18 minutes. After 50 minutes, the lockdown was lifted.
Some Seminole High students said the lockdown was uncalled for.
Mandi Karkheck, a junior, said officials later said over the school's intercom that the lockdown was triggered by the assignment.
"I don't think it was a big deal," she said.
But Winkler said people can never be cautious enough with hazardous situations.
"It's a good intent call from the school administrator," Winkler said.
Times staff writer Curtis Krueger contributed to this report. Laura C. Morel can be reached at (727) 893-8713, or email@example.com.