Inert gas In food packaging, inert gases are used as a passive preservative, in contrast to active preservatives like sodium benzoate (an antimicrobial) or BHT (an antioxidant). Historical documents may also be stored under an inert gas to avoid degradation. For example, the original documents of the U.S. Constitution is stored under humidified argon. Helium was previously used, but it was less suitable because it diffuses out of the case more quickly than argon. Inert gases are often used in the chemical industry. In a chemical manufacturing plant, reactions can be conducted under inert gas to minimize fire hazards or unwanted reactions.
Phase-out of incandescent light bulbs significant health risks to adults, including pregnant women, or to children. If all electricity was generated by a coal power plant (which produce about half the electricity the U.S. consumes) and fluorescent light bulbs were all recycled with no mercury being lost, nearly 75% less mercury could be released in power plant emissions if incandescent bulbs were replaced by fluorescents, and with significantly less total mercury release even if no recycling occurred. However, a concern is that broken bulbs will introduce the mercury directly into a populated indoor area. Though more recent analysis indicates that the concerns about mercury release