Reducing energy use is important because most energy production contributes to problems such as carbon dioxide emissions (tied to global warming), mercury releases, acid rain, volatile organic compoundsCompounds that evaporate easily (volatile) at room temperature and often have recognizable odor; primarily used in solvents; many are chlorinated hydrocarbons and some are carcinogenic (e.g. benzene, chloroform, and methyl ethyl ketone)., and nuclear waste. The U.S. Environmental Protection Agency and U.S. Department of Energy developed the Energy Star label to help purchasers identify energy-efficient products. These products reduce utility bills and help the environment.