No. Safety and reliability are often linked but are not the same thing. Safety is defined in the IEC 61508 standards as “freedom from unacceptable risk.”
A safe system should protect from hazards whether it is performing reliably or not. Safety engineering assures that a safety system performs as needed, even when pieces fail. In fact, safety engineers assume that systems will fail, and design accordingly.
Reliability is a measure of how well the system does exactly what it is intended to do when operated in a specific manner. A reliable system may not always be a safe system. The challenge in functional safety is to ensure that a system is both reliable and safe.