The incident happened Wednesday at a middle school in Shawnee.
Police say the 12-year-old poured hand sanitizer on his own hand, lit it on fire and flicked it toward the 13-year-old. A school nurse treated the older boy’s face before his parents took him to a doctor.
The 12-year-old is facing juvenile charges. Investigators say he told officers he learned what he thought was a party trick from an older student.
Police said the incident appears to have been meant as a prank but could have caused serious injury.