A seat back for a vehicle includes a frame and a deployable device. The deployable device includes a back panel fixed to the frame, a front panel opposite the back panel, and a cavity between the back panel and the front panel. The seat back includes an inflator in communication with the cavity of the deployable device. The deployable device is formed of a plastic material. During a frontal impact of the vehicle, the deployable device may be inflated from an undeployed position to a deployed position to absorb impact from an occupant of the vehicle.