Organisations staffed entirely by volunteers aren't required to carry out a risk assessment. However, it may be difficult to demonstrate that you have fulfilled your duty of care if you don't.
The legal obligations for the health and safety of volunteers are:
- a general duty of care to avoid causing injury
- a duty to ensure that people not in your employment, and who may be affected by your operations, are not exposed to health and safety risks
It is good practice to treat volunteers with the same consideration for health and safety as you would treat paid staff.