A zero-emissions vehicle, or ZEV, is a vehicle that emits no tailpipe pollutants from the onboard source of power. Harmful pollutants to the health and the environment include particulates (soot), hydrocarbons, carbon monoxide, ozone, lead, and various oxides of nitrogen. Although not considered emission pollutants by the original California Air Resources Board (CARB) or U.S. Environmental Protection Agency (EPA) definitions, the most recent common use of the term also includes volatile organic compounds, several air toxics (most notably 1,3-Butadiene), and global pollutants such as carbon dioxide and other greenhouse gases. Examples of zero emission vehicles include muscle-powered vehicles such as bicycles; gravity racers; battery electric vehicles, which typically shift emissions to the location where the electricity is generated e.g. coal or natural gas power plant; and fuel cell vehicles powered by hydrogen, which typically shift emissions to the location where the hydrogen is generated. Hydrogen-powered vehicles are not strictly zero-emissions, as they do emit water or water vapor, although they are still usually included in this category. Emissions from the manufacturing process are ignored in this definition, although the emissions that are created during manufacture are of an order of magnitude that is comparable to the one of the emissions that are created during a vehicle's operating lifetime.