Natural gas tens of millions of structures that use the fuel, the individual risk of using natural gas is very low. Natural gas heating systems may cause carbon monoxide poisoning if unvented or poorly vented. In 2011, natural gas furnaces, space heaters, water heaters and stoves were blamed for 11 carbon monoxide deaths in the US. Another 22 deaths were attributed to appliances running on liquified petroleum gas, and 17 deaths on gas of unspecified type. Improvements in natural gas furnace designs have greatly reduced CO poisoning concerns. Detectors are also available that warn of carbon monoxide and/or explosive gas (methane, propane,
Natural gas prices above shale deposits compared to the rest of the US, highlighting that natural gas markets have become less integrated due to pipeline capacity constraints. Prices of natural gas for end-consumers vary greatly throughout Europe. One of the main objectives of the projected single EU energy market is a common pricing structure for gas products. A recent study suggests that the expansion of shale gas production in the U.S. has caused prices to drop relative to other countries, especially Europe and Asia, leaving natural gas in the U.S. cheaper by a factor of three. It is expected that the TTIP trade