Safety systems and material testing systems including safety systems are disclosed. An example material testing system includes: an actuator configured to control an operator-accessible component of the material testing system; an actuator disabling circuit configured to disable the actuator; and one or more processors configured to: control the actuator based on a material testing process; monitor a plurality of inputs associated with operation of the material testing system; determine, based on the plurality of inputs and the material testing process, a state of the material testing system from a plurality of predetermined states, the predetermined states comprising one or more unrestricted states and one or more restricted states; and control the actuator disabling circuit based on the determined state.