Police said the substance an 11-year-old Tulsa elementary student put in his teacher's coffee cup turned out to be decorative sand.
A bag containing the red powder was found at the school Tuesday and taken to the Tulsa Police Department's laboratory for testing, Officer Lucky Lamons said.
Lamons said lab tests performed Wednesday determined the substance was sound. He said there were no traces of poison or drugs in the coffee.
The teacher drank some of the coffee before learning something might have been put in it. She did not become ill and returned to work the next day.
Police said a witness told them the boy said he did not like the teacher and that he was going to poison her and all the other teachers at the school.
District spokesman John Hamill said no child has been disciplined as a result of the incident because ``it was inconclusive as to which child was responsible.''