CQAs are best determined by risk analysis when considering the intended use of the compressed gas in the facility. Without restricting the type of gas under consideration, the CQAs are most generally defined as:• Moisture content• Total hydrocarbons• Particles• Viable particles (bacteria)During the design and construction phases, other potential contaminants may be introduced as distribution systems are built, such as cutting oils, cleaning agents, or other materials used during system construction or subsequent maintenance activities. A risk analysis should be conducted to assess the likelihood of these other contaminants being present, to assist with the mitigation of their sources, and to develop testing strategies that may be applicable.