No well-defined regulatory requirements exist regarding the frequency, extent, or method of routine sampling for compressed air or other process gases. None of the pharmacopeia monographs specifies limits for particles or total viable counts (bacteria), but some consensus standards and US FDA guidance documents provide additional information and should be consulted as part of the risk analysis process.Some monographs stipulate that the moisture content of compressed air and other process gases should be below -46°C (-50°F).10 USP monographs indicate no standard methods for air sampling.