Police used pepper spray to restrain two 15-year-old pupils after officers were called to a school disturbance.
Teachers reported a boy was acting violently and causing damage at St Benedict's School in Whitehaven, Cumbria, on Tuesday.
The pupil resisted arrest before a girl got involved, who allegedly bit an officer's hand. Both were arrested.
The girl was charged with obstructing an officer and assaulting an officer. The boy was bailed.
Cumbria Police said the girl, who cannot be named, will appear in youth court on 19 December.
The boy had been questioned on suspicion of criminal damage, resisting arrest and a public order offence.
PAVA (pelargonic acid vanillylamide) spray has recently been used by forces and is said to be safer than the previously-used CS spray.
The spray causes the eyes to close and is extremely painful.
A Cumbria Police spokesman said: "Before the deployment of PAVA spray, officers are trained to assess the situation and make a decision on the appropriate use of force necessary to resolve the incident.
"This case is unusual given that PAVA spray was used on school premises.
"However, the officers attending the incident believed the use of PAVA was appropriate given the violent situation they were confronted with.
"The effects of the spray wear off quickly and there is no lasting damage."