Also called dilution ventilation, is different from local exhaust ventilation because instead of capturing emissions at their source and removing them from the air, general exhaust ventilation allows the contaminant to be emitted into the workplace air and then dilutes the concentration of the contaminant to an acceptable level (e.g., to the PEL or below). Dilution systems are often used to control evaporated liquids. Hazardous Material means a material that has one or more of the following characteristics: (a) has a flash point below 140F, closed cup, or is subject to spontaneous heating; (b) has a threshold limit value below 500 ppm in the case of a gas or vapor, below 500 mg/m3 for fumes, and below 25 mppcf in case of a dust; (c) has a single dose oral LD50 below 500 mg/kg; (d) is subject to polymerization with the release of large amounts of energy; (e) is a strong oxidizing or reducing agent; (f) causes first degree burns to skin in short time exposure, or is systemically toxic by skin contact; or (g) in the course of normal operations, may produce dusts, gases, fumes, vapors, mists, or smokes which have one or more of the above characteristics