Garner police charged 18-year-old Andrew Garrett Eye, of Raleigh, with possession of a weapon of mass death and destruction.
They say Eye mixed chemicals in a two-liter bottle to set off the blast near a mobile classroom around 10:45 a.m.
No one was hurt and the explosion didn't cause any damage.
Police don't believe Eye is affiliated with any group.
Eye was arrested and taken to the Wake County Jail.