These requirements cover accessories intended for direct connection to the low or delivery pressure side of compressed gas regulators. These devices are not intended for direct connection to high or storage cylinder pressures. Accessories covered by these requirements are intended for use with compressed gases such as air@ carbon dioxide@ inert gases@ fuel gases@ nitrogen@ nitrous oxide and oxygen. The suitability of an accessory in combination with a compressed gas regulator shall be judged under the applicable requirements of the Standard for Compressed Gas Regulators@ UL 252. These requirements do not cover: a) Flow characteristics@ b) The physiological effects of accessories to be used with medical gases@ c) Accuracy of pressure gauges and flow indicators@ nor d) Accessories that are covered by other UL standards.