Multiple layers of protection are widely advocated as a means of avoiding putting all the eggs in one basket.

The layers of protection that can be improved or are even under the control of a project can vary widely, but are generally based upon the gradually expanding range of influence of a hazard or accident.

For example, the layers of protection for a chemical plant could include: basic design and choice of materials (e.g. chemical pathway), control systems (e.g., automatic shutdown systems), operator control (e.g., alarms and intervention), damage limitation (e.g., firewalls and helmets), emergency response (e.g., sprinkler systems), and evacuation (e.g., plant and surrounding areas).

Some principles of risk reduction overlap with the layers of protection, adding a prioritisation to it.