The present invention is a nitrous oxide safety system or method that provides a safety control valve actuated by low-vacuum fluids to control the release of nitrous oxide therethrough. The nitrous oxide safety system may include a low-vacuum fluid, a nitrous oxide fluid, a scavenging mask assembly, and a safety control valve. The low-vacuum fluid is generated by a vacuum source operating to achieve a predetermined parameter and the nitrous oxide fluid is provided by a nitrous oxide source. The scavenging mask assembly is fluidly connected with the nitrous oxide source and the vacuum source. The safety control valve is fluidly connected to the fluid connection between the nitrous oxide source and the vacuum source. The safety control valve is configured to be actuated when the low-vacuum fluid is input to the valve to release a flow of the nitrous oxide fluid through the safety control valve.