Due to the ease of creation, the cost of Liquid Nitrogen is on par with that of bottled water in the United States. It should also be noted that, due to extreme cooling associated with nitrogen (which boils at around 77 Kelvin, or -196 Centigrade), the additional problem of "frozen air" is encountered when transfering and storing the stuff. Oxygen, for instance, boils slightly hotter, about 90 kelvin, and so, particularly when dealing with rapidly expanding gases coming from a dewar of nitrogen, it is quite possible to accumulate solid Nitrogen and/or Oxygen during transfer or creation processes. This is markedly similar to the issue of solid nitrogen, which becomes a serious impediment to much low-temperature scientific work at liquid helium temperatures.