The incident happened at a school for children with learning difficulties in the seaside resort of Ostend. The pupil was held for a while, but later released. The youngster is training to become a professional house painter and was involved in a house renovation when the incident occurred. He alerted the teacher to the doctored water just in time.
The youngster is already under the supervision of a youth magistrate. He had been at loggerheads with the teacher for some time before the incident.
White spirit is used to clean paint brushes and is a toxic substance.