end of their lifetime or if stressed enough. While not as violent as the explosion of a xenon short-arc bulb, they require caution. As a result, HMI lamps should not be used beyond half of their rated life, and care should be taken with larger lamps when striking (turning on the lamp), as a lamp is most likely to explode within the first five minutes of striking. For this reason, each HMI lamp will usually carry with it a detailed log of the number of strikes and number of hours it has been used. Care should be taken transporting the lamp and replacing lamps. The gases in an HMI lamp are under a very small pressure, but it does increase with temperature. As with quartz-halogen bulbs, care should be taken not to touch the glass directly as skin oils left behind on the envelope can heat beyond the working temperature of the envelope and cause bubbling and/or a weak point. For this reason, anytime a lamp is handled it should be cleaned with an isopropyl alcohol wipe. Most lamp housing designs are inherently tougher and thicker than traditional tungsten units so that in the event of a bulb explosion, those nearby are protected from flying debris. There is the possibility of the front lens element on the lamp head cracking from thermal shock (though not completely blowing out or shattering). Proper safety procedures should always be followed when using HMI units, as they can be dangerous if misused. In 2014, journalist Kerry Sanders reported that he had been blinded for 36 hours as a result of overexposure to ultraviolet light from a malfunctioning HMI lamp. Had the fixture included UV protection as is required by OSHA, the output from the lamp would have had no effect. See also High-intensity discharge lamp (HID) List of light sources Large Image Projection Large Format Slide Projector References General Box, Harry. Set Lighting Technician's Handbook 3rd Ed., Focal Press, 2003. Short Arc Metal Halide Lamps Technology and Application: Metal Halide Lamps, Photo Optic. OSRAM Gas discharge lamps Film and video technology