It is imperative that organizations assess the risks inherent to volunteering as well as the management strategies to minimize and respond to those risks. This means asking what risks exist for volunteers (working outdoors, operating machinery, stress and fatigue) as well as what risks could volunteers pose to the organization (liability, representing the organization inappropriately, harm to vulnerable populations).
With a fuller understanding of potential risks, the organization can then determine if they have the capacity to address those risks. For example, are there enough staff to oversee volunteers? Is there access to screening facilities? Is the organization eligible for insurance coverage? How would/could staff handle an emergency situation? Answering these difficult questions will help make sure your volunteers, and your organization, are well-cared for and protected.
An additional note: Risk management should be ongoing, so consider scheduling regular reassessments.
When it comes to risk management resources, it's difficult to find a better source than the Nonprofit Risk Management Center; they offer numerous tools and training opportunities, including the free online No Surprises Volunteer Risk Management Tutorial.