Volunteers are not members of staff, but the law requires that the school should safeguard their health and safety. Ultimate responsibility rests with the employers: the LEA, or governors or trustees. But the day-to-day responsibility will be delegated to the head and staff.
The competence and suitability of volunteers working with children must be checked. DfES guidance, Child Protection: Preventing Unsuitable People from Working with Children and Young Persons in the Education Service, provides details of the pre-appointment checks that should be made. Volunteers are also expected to have the same standards of expertise, discipline, relationships and risk management expected of all adults working with pupils. It is essential that they are aware of safe practices that are expected.
Sometimes it is acceptable for a volunteer with a particular expertise to work away from a teacher. But a teacher should always be present when a high-risk activity is taking place and the school must carry out a risk assessment.
Volunteers are covered by the employer's public liability insurance, but they may not be covered by the employer for personal injury. Schools should make clear the insurance position to the volunteer.