The American Standard Safety System, or ASSS, is a connection system for gas cylinders with a volume exceeding 25 cubic feet. The connections differ in thread type and size, right and left handed threading, internal and external threading, and nipple-seat design. This variability reduces the risk of errors such as administering the wrong gas to a patient, or utilizing equipment calibrated for one gas with another. However, as there are only 26 connections for the 62 gases and mixtures recognized by the CGA, connections are not unique.