In occupational safety and health, an incident is an unexpected, unintentional event that has unwanted consequences, while an accident is a type of incident that results in damage, injury, or harm. Every accident can be an incident, but not all incidents can be termed as an accident. A near miss is an unplanned event that did not result in injury, damage, or illness, but could have done so. Incidents can involve any sort of damage, hazard, or minor injury that threatens the productivity and success of the project, while accidents always refer to a serious, harmful event.

It is important to prevent both incidents and accidents, and most companies define an incident as any harmful worksite occurrence that results in damage to property or equipment, minor injury, or any other unintended negative worksite event that falls short of a serious injury. Investigating a worksite incident, whether it is a fatality, injury, illness, or close call, provides employers and workers the opportunity to identify hazards in their operations and shortcomings in their safety and health programs.

The term "incident" is used in some situations and jurisdictions to cover both an "accident" and "incident". It is argued that the word "accident" implies that the event was related to fate or chance, while the term "incident" is preferred because it avoids calling up unwanted associations when discussing unintended safety and health events with workers. By defining incidents and accidents, companies can lay the framework for determining how they happened and figure out where something went awry, which is important for preventing negative events in the future.