10 CFR §431.282

Ballast means a device used with an electric discharge lamp to obtain necessary circuit conditions (voltage, current, and waveform) for starting and operating. High intensity discharge lamp means an electric-discharge lamp in which— Mercury vapor lamp means a high intensity discharge lamp, including clear, phosphor-coated, and self-ballasted screw base lamps, in which the major portion of the light is produced by radiation from mercury typically operating at a partial vapor pressure in excess of 100,000 Pa (approximately 1 atm). Mercury vapor lamp ballast means a device that is designed and marketed to start and operate mercury vapor lamps intended for general illumination by providing the necessary voltage and current. Specialty application mercury vapor lamp ballast means a mercury vapor lamp ballast that—

(1) The light-producing arc is stabilized by the arc tube wall temperature; and

(2) The arc tube wall loading is in excess of 3 Watts/cm 2, including such lamps that are mercury vapor, metal halide, and high-pressure sodium lamps. (1) Is designed and marketed for operation of mercury vapor lamps used in quality inspection, industrial processing, or scientific use, including fluorescent microscopy and ultraviolet curing; and (2) In the case of a specialty application mercury vapor lamp ballast, the label of which— (i) Provides that the specialty application mercury vapor lamp ballast is ‘For specialty applications only, not for general illumination’; and (ii) Specifies the specific applications for which the ballast is designed.