Abstract: A safety strap device for hazardous materials containers includes a hazardous materials container having an outer wall and a retractable safety strap device mounted within the hazardous materials container. The safety strap device includes an extendable and retractable securement strap having an outer end, the securement strap extending outwards from the safety strap device through the outer wall of the hazardous materials container, a biasing device operative to forcibly retract the securement strap into the safety strap device and a strap extension and retraction locking device operative to prevent extension and retraction of the securement strap when engaged. Finally, a latch device is mounted on the outer end of the securement strap for releasably connecting the securement strap to a selected securement point thereby releasably securing the hazardous materials container in an upright position.