Three fourth graders in a New York elementary school plotted to kill their teacher with hand sanitizer in December, The New York Daily News reported.

The 9-year-old students, who attend Elba Elementary School in upstate New York, allegedly told fellow students they were going to kill their teacher “by putting antibacterial products around the classroom,” according to the police report.

The teacher is extremely allergic to hand sanitizer and banned it from the classroom, and so the students planned to poison her with it. However, the plot was foiled when a fellow student told their parents, who then referred it to the school board.

Chief Deputy Jerome Brewster of the Genesee County Sheriff’s Department told the Daily News that police had found little motive for the scheme beyond the fact that the children said the teacher “is mean.”

However, Brewster also said that authorities considered the plot to be “idle chatter” and did not charge the student with crimes, instead referring the matter to the school district who are treating the threats “very seriously.”

Click for more from The New York Daily News.