A student has been charged after eight other students from a western Sydney high school were allegedly pricked with a used syringe found at a local bus stop.

Emergency services were called to Plumpton High School shortly before midday on Thursday, in response to a report that eight young people had been pricked with a needle.

Four ambulances and seven paramedics went to the school to assess the eight students.

There were no serious injuries and none of the students required treatment, although an ambulance spokesman said all would be taken to a local hospital or GP for a series of tests, "to eliminate risks of hepatitis B, hepatitis C and HIV".